Rozprawy doktorskie na temat „Weaning weight”

The objective of these studies was to evaluate the effect of piglet nursing location on weaning weight, and its dependence on essential oil supplementation on sow and piglet performances. Piglets that nursed anterior teat pairs had heavier weaning weights and higher gain for the lactation period. Additionally, piglet birthweight did not impact their overall teat selection and nursing location. These results provide some insight into the biological aspects of sow milk production, and implied that milk yield may vary between teat pairs along the udder line. Supplementation of essential oils (EO) during late gestation and lactation had no effect on sow fecal dry matter (DM), immunoglobulin content of colostrum and milk, but it did increase the lactose content in milk from sows supplemented with EO, with an increase from 5.84% to 5. 97% (P = 0.04). There was an increase in sow weight loss during lactation (P = 0.002), and there was a significant effect on piglet birthweight, with sows supplemented with EO producing heavier piglets at birth, 1.56 kg in EO sows, compared to 1.49 kg in the control (CON) sows (P = 0.03). Overall, piglet weaning weight is impacted by their selected nursing location along the udder line. Supplementation of EO may have limited effects on sow performance, such as fecal dry matter (DM) but may positively impact piglet birthweight. Furthermore, including EO into sow diets during late gestation and lactation can potentially impact the nutrient levels of sow milk.

This study was carried out in swine production facilities of the School of Veterinary Medicine and Zootechnic Studies at the Rural Academic Unit of Carmen Pampa. The objective of this study was to evaluate the effects of weaning male and female piglets at different times on their weight gain and the fertility of the sows. Four three year old sows that had a total of 40 piglets (25 males and 15 females) were used. The piglets were distributed across the following treatments: T1 - weaning 9 piglets (5 males and 4 females) at 56 days, T2 - weaning 13 piglets (7 males and 6 females) at 46 days, T3 - weaning 7 piglets (5 males and 2 females) at 36 days, and T4 - weaning 11 piglets (8 males and 3 females) at 26 days. This was followed by three weekly weight management phases in both sexes: Beginning (1-56 days), Growth (1-112 days), and Finished (1-150 days). A completely randomized design with different numbers of repetitions was used to analyze the results. The ANOVA test for weight gain did not show significant differences between treatments (p>0.05) in the beginning, growth, and finished stages for male piglets. The ANOVA test for weight gain in females during the initial phase showed significant differences (p<0.05). The Duncan test showed that T3 (12.50 kg) and T1 (10.80 kg) as well as T1 (10.80 kg) and T2 (9.41 kg) are equal. In addition, T2 (9.41 kg) and T4 (7.20 kg) are similar. In the growth phase there were no significant differences (p>0.05). In the fattening phase there were significant differences (p>0.05). The Duncan test showed that T3 (60.50 kg), T2 (56.42 kg), and T1 (54.75 kg) are equal and that T1 (54.75 kg) and T4 (43.33 kg) were similar at the end of the trial. The comparison of males and females was done via the student t test and indicated that there was no significant difference between males and females. The sow in T3 (44 days) recorded the best postpartum fertility. In general, treatment T3 (weaned at 36 days) showed the best results for both weight and fertility.

Thesis (M.Sc.) (Agriculture) --University of Limpopo, 2007
The objectives of this study were to evaluate the effect of pre-weaning selection on estimates of genetic parameters for post-weaning average daily gain in Phases C (ADG-C) and D (ADG-D) and to estimate genetic relationships between average daily gain in the two phases. Performance records of the South African Angus cattle breed was used in the analysis. (Co)variance components and genetic parameters for weaning (WWT), AGD-C and ADG-D were estimated by REML procedures fitting three different models (Models 1, 2 and 3) that differed in how they integrated sequential selection in the analysis of post-weaning traits. Model 1 was a univariate model of WWT, ADG-C and ADG-D. Model 2 was a two trait model of WWT and either ADG-C or ADG-D. Model 3 was a three trait model of WWT, ADG-C and ADG-D. Estimates of heritability for ADG-C were 0.39±0.08, 0.42±0.06 and 0.44±0.01 from Model 1, 2 and 3 respectively. Corresponding estimates of heritability for ADG-D were 0.18±0.021, 0.19±0.021 and 0.21±0.02 respectively. An estimate of genetic correlation between ADG-C and ADG-D was 0.58± and it suggested that the two traits may not necessarily be under the same genetic control. Rank correlations for all bulls based on ADG-C estimated breeding values (EBV’s) were 0.92, 0.83 and 0.94 for Model 1 vs. Model 2, Model 1 vs. Model 3 and Model 2 vs. Model 3 respectively. Corresponding ADG-D EBV’s rank correlations were 0.88, 0.84 and 0.93. Rank correlations for top and bottom 1%, 5% and 10% were lower than those for all bulls in both ADG-C and ADG-D. Low rank correlations showed that the difference in magnitude of genetic parameters from different models was enough to alter bull rankings based on EBV’s of ADG-C and ADG-D. Hence it was concluded that inclusion of pre-weaning information in genetic analysis for post-weaning average daily gain is necessary to account for selection at weaning.
the THRIP (Technology and Human Resource for Industry Project) and NRF (National Research Foundation).

O peso dos leitões ao desmame está positivamente relacionado com o desempenho posterior e sofre influência de diversos fatores relacionados ao ambiente, à matriz e aos próprios leitões. O peso ao nascimento, a presença de lesões orais, dentárias, umbilicais e no aparelho locomotor podem comprometer o ganho de peso dos leitões na maternidade. Foram acompanhados 2004 lactentes, os quais foram pesados e avaliados para a presença de lesões no primeiro dia e aos 7, 14 e 21 (desmame) dias de vida. Leitões nascidos com peso entre 600g e 900g tiveram mortalidade até o desmame superior àqueles pesando entre 901g e 1200g (P<0,05). Entre os leitões nascidos com peso acima de 1500g não houve diferença na mortalidade (P>0,05). O peso ao nascimento apresentou correlação positiva com o peso ao desmame (P<0,05). A ocorrência de lesões orais, umbilicais ou dentárias não comprometeu o desempenho. Por outro lado, a presença de lesões no aparelho locomotor afetou negativamente o peso ao desmame (P<0,05). Leitões com lesões no aparelho locomotor na segunda semana de vida apresentaram peso inferior àqueles com lesões na primeira semana (P<0,05). Leitões leves (≥600g - <1300g) com lesões no aparelho locomotor não sofreram redução do peso ao desmame (P>0,05), enquanto os leitões médios (≥1300g - <1800g) e pesados (≥1800g) com lesões tiveram peso inferior ao daqueles sem lesões (P<0,05). O peso ao nascimento e a ocorrência de lesões no aparelho locomotor podem comprometer a performance dos leitões lactentes.
Weaning weight of piglets is positively related with performance in later ages and is influenced by several factors connected with environment, the sow and the piglets. The birth weight, presence of oral, dental, umbilical or limb lesions can compromise the performance of suckling piglet. A total of 2004 suckled piglets were weighted and evaluated for the presence of lesions in the first day of life and on 7, 14 and 21 days. Pigs with birth weight between 600g and 900g presented preweaning mortality higher than those with weights between 901g and 1200g (P<0.05). Among piglets with birth weight above 1500g, there was no difference in mortality (P>0.05). Birth weight presented a positive correlation with weaning weight (P<0.05). Occurrence of oral, umbilical or dental lesions did not compromise performance. On the other hand, the presence of limb lesions affected negatively the weaning weight (P<0.05). Piglets with limb lesions in the second week of life presented smaller weight when compared with those with lesions only in the first week of life (P<0.05). Lighter piglets (≥600g - <1300g) with limb lesions did not show reduction in weaning weight (P>0.05), while those with intermediate weight (≥1300g - <1800g) and heavier (≥1800g) with lesions had smaller weight when compared to those without lesions (P<0.05). It is concluded that birth weight and the occurrence of limb lesions can compromise the performance of suckling piglets.

The purpose of this study was to investigate the effect of prepartum and postpartum nutrition on milk production of commercial beef cows. Forty-three Angus or Angus X Holstein females, ranging in age from 2 to 6 yr, were randomly assigned by age and percentage Holstein within age to one of two prepartum grazing treatments (PRE). All females, regardless of PRE, were assigned at calving to receive the same post-calving nutritional energy. Females were assigned at calving by age, percentage Holstein within age, prepartum nutritional treatment and calving date to one of two milking groups. Milk weight (grams), milk composition (fat, protein, lactose, solids-not-fat, somatic cell count), dam body condition score (1 to 9), dam body weight, dam backfat thickness, loineye area, calf weaning weight and postpartum interval to estrus were all evaluated. Milk removal occurred biweekly by vacuum milking machine after intravenous injection of 20 IU of oxytocin. Samples were weighed and taken for milk analysis and determination of milk components. At 76± 10 d post-calving, females were assigned by age, percentage Holstein within age, prepartum nutritional treatment, and calving date to receive one of two postpartum nutritional treatments (POST). Females continued to be milked by machine biweekly until calves were weaned 199 ± 10 d. Differences in grazing level prior to calving significantly effected calf birth weights, with dams on the prepartum restricted grazing being lighter in weight at birth, 36.69 ± .68 and 38.95 ± .81 kg for PRE-L and PRE-H groups, respectively, however grazing differences did not effect calf weaning weight, calf gain or calf average daily gain. POST nutritional treatments significantly effected all calf performance traits with 37.10±.70, 38.54±.88; 196.89±4.9, 213.33±6.2; 159.79±4.8, 174.78±6.0; .809±.024, .888±.030; for birth weight, weaning weight, calf gain and calf average daily gain from cows on the POST -M or POST -H nutritional treatments, respectively. Pre-partum nutrition effected milk production (P < .001) with dams from the PRE-L grazing group producing less milk, 5622 ± 75 vs 6888 ±80 g. Postpartum energy also effected milk production with dams on the POST-H energy level producing more milk than dams from the POST-M group. Percentages of fat, protein, lactose and solids-not-fat were not different between the prepartum or postpartum diets (P>. 10). Somatic cell count was negatively correlated with dam milk production (P< .03). Postpartum interval to estrus was shorter for the PRE-L group than for the PRE-H, 43 ± 4 vs 53 ± 4 d.
Master of Science

Orientador: Sandra Aidar de Queiroz
Banca: João Ademir de Oliveira
Banca: William Koury Fillho
Resumo: O objetivo foi estudar a influência da idade da vaca ao parto (IVP), da idade do animal ao sobreano (IS) e do peso ao sobreano (PS) sobre os escores de conformação (C), precocidade (P), musculatura (M) e temperamento (T) ao sobreano de animais Nelore; estimar a herdabilidade (h²) destas características, empregando-se diferentes modelos estatísticos e estimar as co-variâncias e correlações entre T e as características reprodutivas perímetro escrotal (PE), idade ao primeiro parto (IPP) e idade ao segundo parto (ISP), de bovinos Nelore. A base de dados utilizada pertence ao PAINT®, CRV Lagoa LTDA. Foram realizadas análises de regressão após a absorção do efeito de grupo de contemporâneos (GC). As estimativas de h² foram obtidas por máximaverossimilhança restrita sob um modelo animal, considerando-se o efeito genético aditivo de animal como aleatório, incluindo diferentes efeitos fixos. IVP apresentou efeito quadrático sobre P e M, segmentado quadrático-quadrático sobre C e linear sobre T. A característica C comportou-se de modo similar ao PS e P e M foram semelhantes ao ganho de peso neste período. IS e PS apresentaram efeitos quadráticos sobre C, P e M e efeito cúbico e linear, respectivamente, sobre T. Estimativas de h² foram encontradas entre 0,13 á 0,38 (C, P e M) de acordo com o modelo utilizado, enquanto para PE, IPP e ISP, as estimativas foram iguais a 0,52; 0,13 e 0,03. As correlações genéticas entre T e PE, T e IPP e T e ISP foram de 0,16; -0,04 e -0,32. As correlações estimadas entre T e as características reprodutivas foram de pequena magnitude. A seleção para os escores visuais pode trazer ganhos genéticos moderados nas características de carcaça
Abstract: The aims of this study were to study the effect of age at calving (IVP), age of yearling (IS) and yearling weight (PS) on the scores of conformation (C), precocity (P), muscle (M) and temperament (T) of yearling Nellore, to estimate heritability (h ²) of these traits, using different statistical models and to estimate the covariance and correlation between T and the reproductive traits scrotal circumference (SC), age at first calf (IPP) and age at second calf (ISP). The database used belongs to the breeding program PAINT ® of CRV Lagoa LTDA. Regression analysis were performed after the absorption of the effect of contemporary group (CG). Estimates of h² were obtained by restricted maximum likelihood method under an animal model, considering the genetic effect of animal as random, with different fixed effects. IVP showed a quadratic effect on P and M, segmented quadratic-quadratic and linear on C on T, respectively. C showed similar patter as PS while P and M were similar to weight gain in this period. IS and PS showed a quadratic effect on C, P and M and cubic and linear effects, respectively, on T. The estimates of h ² ranged from 0.13 to 0.38 (C, P and M) according to the model used, whereas for PE, IPP and ISP, the estimates were equal to 0.52, 0.13 and 0, 03. Genetic correlations between T and PE, T and IPP and T and ISP were 0.16, -0.04 and -0.32. The estimated correlations between T and the reproductive traits were small. Selection applied on visual scores could bring moderate genetic gains to the carcass traits
Mestre

[EN] The aim of this thesis was to evaluate the productive performance of a rabbit line (OR-LS) selected by ovulation rate during first 6 generations (period 1), and later by ovulation rate (OR) and litter size (LS) during 11 generations using independent culling levels (Period 2). Genetic parameters, direct response for OR and LS and the correlated response for embryo (ES), foetal (FS) and prenatal survival (PS) were estimated. Also, the correlated response on growth rates (GR), weaning (WW) and marketing weight (MW) were estimated. The objective of chapter 3 was to estimate the genetic parameters of the productive traits and the response to selection by OR and LS of OR-LS line. For traits analysis, Bayesian methods were used. Heritability values of litter size traits were low, 0.10, 0.07, 0.07 and 0.07 for litter size, number of born alive (NBA), number of kits at weaning (NW) and marketing (NM), respectively. Heritability for OR was moderate (0.25), while it was low (0.13 and 0.14) for number of implanted embryos (IE) and number of live foetuses at 12 days of gestation (LF12), respectively. Low heritability values for survival traits were found, 0.09 for embryo survival (ES), 0.16 for foetal survival (FS) and 0.14 for prenatal survival (PS). In the second period, after 11 generations of selection by OR and LS, a genetic response of 0.17 kits per generation for LS was achieved. This response was higher than the obtained in period 1 (0.07 kits per generation), in which just selection by OR was performed. The opposite effect was found for OR; the highest response for OR appeared in the first period (0.24 ova per generation) versus the second period (0.17 ova per generation). This reduction in OR response can be due to the decrease in selection differential during the second period of selection. Since high genetic correlations were obtained for LS and other litter size traits, a positive correlated response was observed for NBA, NW and NM (0.12, 0.12 and 0.11 kits per generation, respectively) in the second period. In the first period, no correlated response on ES was observed and a decrease in FS (-0.04) was found. Nevertheless, in the second period a correlated response on PS appeared due to an improvement in both ES (0.04) and FS (0.03). Summarizing, the improvement in litter size in the second period is due to an increase in ovulation rate as well as an increase in prenatal survival. The objective of chapter 4 was to study the correlated response on growth traits in the OR-LS line in both periods of selection, the selection by OR during six generations and the selection by independent levels by OR and LS during 11 generations. The heritability estimates were low for weaning weight (WW), marketing weight (MW) and growth rate (GR), 0.09, 0.13 and 0.14, respectively. The estimated genetic correlations of WW, GR and MW with LS were around zero and with OR were positive and from low (0.19) to moderate (0.38). The positive moderate genetic correlation estimated between OR and MW could explain the correlated response found in MW. Correlated response on WW could be explained by positive and high genetic correlation between MW and WW. The aim of chapter 5 was to investigate magnitude and timing of embryo and early foetal survival in females with high OR using hormonal treatment as a model for selection by OR. Two groups of females (treated and untreated) were used. Treated females were injected with 50 IU eCG 48 hours before mating. Females were slaughtered at day 18 of gestation. OR, IE, LF12 and LF18 were recorded. Besides, ES (IE/OR), FSLF18 (LF18/IE), FSLF18/LF12 (LF18/LF12) and PSLF18 (LF18/OR) were estimated. Treated females had a higher OR than untreated females. According to the previous results for OR and LF18, treated females showed a lower survival rate from ovulation to 18 d of gestation. Treated females also had lower embryo and foetal survival. Main difference in foetal survival appeared from day 12 to 18 of gestation.
[ES] El objetivo de esta tesis fue evaluar el tamaño de camada de una línea de conejo seleccionada por tasa de ovulación durante las primeras seis generaciones (periodo 1) y después por tasa de ovulación (OR) y tamaño de camada (LS) durante 11 generaciones mediante el método de niveles independientes (periodo 2). Se estimaron los parámetros genéticos, así como la respuesta en OR y LS y la respuesta correlacionada en los caracteres reproductivos (capítulo 3). Además, se evaluó la respuesta correlacionada en los caracteres de crecimiento (capítulo 4); peso al destete (WW), peso al sacrificio (MW) y ganancia de peso entre el destete y el sacrificio (GR). Para el análisis de los caracteres se utilizaron métodos bayesianos. El objetivo del capítulo 3 fue estimar los parámetros genéticos de los caracteres reproductivos y la respuesta a la selección. Los valores de heredabilidad de los caracteres del tamaño de camada fueron bajos (alrededor de 0.10). La heredabilidad estimada para OR fue moderada (0.25), mientras que fue baja para el número de embriones implantados (IE) y el número de fetos vivos a los 12 días de gestación (LF12). Se obtuvieron valores bajos de heredabilidad; 0.09 para la supervivencia embrionaria (ES), 0.16 para la supervivencia fetal (FS) y 0.14 para la supervivencia prenatal (PS). En el periodo 2, se obtuvo una respuesta genética de 0.17 gazapos por generación para LS. Esta respuesta fue mayor que la obtenida en el periodo 1. En el caso de la tasa de ovulación, la mayor respuesta en OR se obtuvo en el periodo 1 (0.24 óvulos por generación) versus (0.17 óvulos por generación) en el periodo 2. Esta reducción en la respuesta de OR se puede atribuir a la disminución del diferencial de selección durante el período 2 de selección. De acuerdo con la alta correlación genética entre LS y otros caracteres del tamaño de camada, también se observó una respuesta correlacionada positiva en el número de nacidos vivos (NBA), destetados (NW) y comercializados (NM); 0.12, 0.12 y 0.11 gazapos por generación, respectivamente, en el segundo periodo. En el primer periodo no se observa respuesta correlacionada en la SE y se produce una disminución de la SF (-0.04). Sin embargo, en el segundo periodo se produce una respuesta correlacionada positiva en la SP que se debe a una mejora de la SE (0.04) y SF (0.03). En resumen, la mejora del tamaño de camada en el segundo periodo se debe tanto a un aumento de la tasa de ovulación como a un aumento de la supervivencia prenatal. El objetivo del capítulo 4 fue estudiar la respuesta correlacionada en los caracteres de crecimiento en esta línea. Las estimas de heredabilidad fueron bajas para los caracteres WW (0.09), MW (0.13) y GR (0.14). Las correlaciones genéticas estimadas de LS con WW, MW y GR fueron cercanas a cero; con la tasa de ovulación, las correlaciones fueron positivas y variaban de bajas a moderadas (de 0.19 a 0.38). La correlación genética moderada entre OR y MW podría explicar la respuesta correlacionada observada en MW. La alta correlación entre MW y WW podría explicar la respuesta correlacionada obtenida para WW. Finalmente, el objetivo de capítulo 5 fue estudiar en hembras con alta tasa de ovulación en qué momento se producen las mayores pérdidas fetales y cómo se ve afectado el desarrollo fetal. Para ello, de un total de 51 hembras, 24 hembras fueron pinchadas con 50 UI de eCG 48 horas antes de la cubrición para aumentar la tasa de ovulación. Las hembras fueron sacrificadas a los 18 días de gestación. Se registró OR, IE y el número de fetos vivos a los 12 y 18 días de gestación (LF18). Las hembras tratadas tuvieron una tasa de ovulación mayor que las no tratadas. De acuerdo con los resultados obtenidos para OR y LF18, las hembras tratadas mostraron una supervivencia más baja desde la ovulación hasta los 18 días de gestación y tuvieron una menor supervivencia embrionaria y fetal. Las principales diferencias en l
[CAT] L'objectiu d'esta tesi va ser avaluar la millora de la grandària de ventrada d'una línia de conill seleccionada per tasa d'ovulació durant les primeres sis generacions (període 1) i després per tasa d'ovulació (OR) i la grandària de ventrada (LS) durant 11 generacions per mitjà del mètode de nivells independents (període 2). Es van estimar els paràmetres genètics, així com la resposta en OR i LS i la resposta correlacionada en caràcters reproductius (capítol 3). A més, es va estudiar la resposta correlacionada en els caràcters de creixement (capítol 4); pes al deslletament (WW), pes al sacrifici (MW) i guany de pes entre el deslletament y el sacrifici (GR). Per a l'anàlisi dels caràcters es van utilitzar mètodes bayesians. L'objectiu del capítol 3 va ser estimar els paràmetres genètics dels caràcters reproductius i la resposta a la selecció. Els valors d'heretabilitat dels caràcters de la grandària de ventrada van ser baixos (al voltant de 0.10). L'heretabilitat estimada per a OR va ser moderada (0.25), mentres que va ser baixa per al nombre d'embrions implantats (IE) i el nombre de fetus vius als 12 dies de gestació (LF12). Es van obtindre valors baixos d'heretabilitat; 0.09 per a ES, 0.16 per a FS i 0.14 per a PS. En el període 2, es va obtindre una resposta genètica de 0.17 llorigons per generació per a LS. Esta resposta va ser major que l'obtinguda en el període 1. En el cas de la tasa d'ovulació, la major resposta per a OR va ser en el primer període (0.24 òvuls per generació) versus (0.17 òvuls per generació) en el període 2. Esta reducció en la resposta d'OR es pot atribuir a la disminució del diferencial de selecció durant el període 2 de selecció. Donada l'alta correlació genètica entre LS i altres caràcters de la grandària de ventrada, també es va observar una resposta correlacionada positiva en el nombre de nascuts vius (NBA), deslletats (NW) i comercialitzats (NM); 0.12, 0.12 i 0.11 llorigons per generació, respectivament, en el segon període. En el primer període no s'observa resposta correlacionada en la SE i es produeix una disminució de la SF (-0.04). No obstant això, en el segon període es produeix una resposta correlacionada en la SP que es deu a una millora de la SE (0.04) i SF (0.03). En resum, la millora de la grandària de ventrada en el segon període es deu tant a un augment de la tasa d'ovulació com a un augment de la supervivència prenatal. L'objectiu del capítol 4 va ser estudiar la resposta correlacionada en els caràcters de creixement en aquesta línia. Les estimes d'heretabilitat van ser baixes per als caràcters WW (0.09), MW (0.13) i GR (0.14). Les correlacions genètiques estimades de LS amb WW, MW i GR van ser pròximes a zero; amb la tasa d'ovulació, les correlacions van ser positives i variaven de baixes a moderades (de 0.19 a 0.38). La correlació genètica moderada entre OR i MW podria explicar la resposta correlacionada trobada per a MW. D'altra banda, l'alta correlació entre MW i WW podria explicar la resposta correlacionada obtinguda per a WW. Finalment. l'objectiu del capítol 5 va ser estudiar en femelles amb alta tasa d'ovulació en quin moment es van produir les majors pèrdues fetals i com es veu afectat el desenvolupament fetal. Per a això, d'un total de 51 femelles, 24 femelles van ser punxades amb 50 UI d'eCG 48 hores abans del cobriment per a augmentar la tasa d'ovulació. Les femelles van ser sacrificades al 18 dies de gestació. Es va registrar OR, IE i el nombre de fetus vius al 12 i 18 dies de gestació (LF18). Les femelles tractades van tindre una tasa d'ovulació major que les no tractades. D¿acord als resultats obtinguts per OR i LF18, les femelles tractades van mostrar una supervivència més baixa des de l'ovulació fins als 18 dies de gestació i van tindre una menor supervivència embrionària i fetal. Les principals diferències en la supervivència fetal van aparèixer entre els dies 12 i 18 de gestaci
Yehia Badawy Elmoghazy, A. (2016). SELECTION FOR OVULATION RATE AND LITTER SIZE IN RABBITS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/73265
TESIS

Dissertação de Mestrado Integrado em Medicina Veterinária
Existem diversos fatores que poderão influenciar o tamanho da ninhada, o peso médio dos leitões ao nascimento e, posteriormente, o número de leitões desmamados/porca e o peso médio dos leitões ao desmame. Um desses fatores é a paridade. Com o intuito de avaliar a influência da paridade na produtividade dos leitões até ao desmame foi analisado o desempenho reprodutivo de 45 porcas F1 (LW x LR). Foram registados para cada porca o número de nados totais (NT), nados vivos (NV) e nados mortos (NM). Os leitões nascidos vivos foram pesados individualmente às 24 horas após o nascimento, totalizando 600 leitões. Posteriormente, foi registado o número de leitões desmamados/porca e o respetivo peso individual dos leitões ao desmame (desmame comercial de 28 dias). Para efeitos de análise estatística, as porcas foram divididas em 4 grupos de diferentes paridades, respetivamente: 3ª-4ª gestação, 5ª-6ª gestação, 7ª-8ª gestação e 9ª-10ª gestações. Os resultados não mostraram diferenças na prolificidade das porcas, nos NM e no peso médio ao nascimento dos leitões para os diferentes grupos de paridades. O número de leitões desmamados também não diferiu consoante a paridade das porcas. Por outro lado, os resultados obtidos no peso médio dos leitões ao desmame e no ganho médio de peso até ao desmame mostraram diferenças para a paridade das porcas. O peso médio ao desmame apresentou valores máximos nos leitões nascidos de 5ª-6ª gestações (6,82 kg) e 7ª-8ª gestações (7,12 kg), tendo alcançado valores mínimos nos leitões nascidos de 9ª-10ª gestações (5,97 kg). O mesmo ocorreu com o ganho médio de peso até ao desmame, apresentando valores máximos nos leitões nascidos de 5ª-6ª gestações (5,47 kg) e 7ª-8ª gestações (5,76 kg), e um valor mínimo nos leitões nascidos de 9ª-10ª gestações (4,69 kg). Embora com as limitações de uma amostra pequena, poderemos concluir que, com um maneio correto, será viável levar as porcas até à 8ª gestação, aproveitando as suas excelentes qualidades reprodutivas e produtivas e amortizando melhor o período improdutivo até ao primeiro parto.
ABSTRACT - There are several factors that may affect the litter size, the average piglet birth weight and later, the number of piglets weaned/sow and the average weaning weight. One of these factores is parity. In order to evaluate the influence of parity on the number of piglets weaned and on the average weaning weight, the reproductive performance of 45 F1 sows (LW x LR) was analyzed. For each litter the numbers of total piglets born, born alive and stillbirths were recorded. Piglet’s birth weight was recorded 24 hours after birth (totalizing 600 piglets), and within-litter mean and standard deviation were calculated. At weaning (28 days), the number of piglets weaned per sow and the individual weaning weight were recorded. Within-litter mean and standard deviation were calculated. For statistical analysis, sows were divided into 4 groups of different parities (3rd-4th parity, 5th-6th parity, 7th-8th parity and 9th-10th parity) and then analyzed on their reproductive performance. Results showed no differences on litter size, stillbirths, piglet’s birth weigh and number of piglets weaned per sow between different parities. On the other hand, the results for average weaning weight and average weight gain to weaning were different between parities. The higher results were obtained on 5th-6th gestations, with a within-litter weaning weight mean of 6.82 kg and on 7th-8th gestations, with a within-litter weaning weight mean of 7.12 kg. The poorest results were obtained on 9th-10th gestations, with a within-litter weaning weight mean of 5.97 kg. The results on the average weight gain per piglet to weaning were similar, with best results obtained on 5th-6th gestations, with an average 5.47 kg gain per piglet, and on 7th-8th gestations, with an average 5.76 kg gain per piglet. The poorest results were obtained on 9th- 10th gestations, with an average 4.69 kg gain per piglet. Despite the limitations of a small sample, we can conclude that, with the right management, it's viable to maintain the sows until the 8th pregnancy, taking advantage of their excellent reproductive and productive qualities and amortizing their unproductive period to the first delivery.

O presente estudo teve como finalidade avaliar o efeito da heterose, ao comparar o crescimento e o peso ao desmame de vitelos em linha pura autóctone ou provenientes de cruzamento de raças autóctones com raças exóticas. A componente prática foi concretizada em 4 explorações agropecuárias, no concelho de Évora e Arraiolos. O ensaio decorreu entre setembro de 2018, acompanhando o início da época de parição e junho de 2019, com os últimos vitelos desmamados. Como principais resultados, pode-se salientar que os vitelos Mertolengos apresentaram pesos vivos aos 90 dias, 210 dias e GMD inferiores e uma idade ao desmame superior aos cruzados de Aberdeen-Angus, Limousine e Charolês. Desta forma, mostrou-se muito vantajoso, em termos de preço de venda, a prática de cruzamentos de uma raça autóctone com raças exóticas especializadas na produção de carne; Crossbreed of Mertolenga with exotic breeds: effect on pre-weaning growth and weaning weight of calves Abstract: The purpose of the present study was to evaluate the effect of heterosis, by comparing the growth and weaning weight of calves of an autochthonous pure line or from crossbreeding of indigenous and exotic breeds. The data were collected in 4 agricultural farms, in the municipality of Évora and Arraiolos. The trial started in September 2018, following the start of the calving season and ended in June 2019, with the last calves weaned. As main results, it can be noted that the Mertolengos calves had live weights at 90 days, 210 days and lower GMD and age at weaning higher than the Aberdeen-Angus, Limousine and Charolais cross. In this way, the practice of crossbreeding of an indigenous breed with exotic breeds specialized in meat production proved to be very advantageous.

Made available in DSpace on 2014-08-20T14:38:44Z (GMT). No. of bitstreams: 1 Dissertacao_Luiza_Sphor.pdf: 192588 bytes, checksum: aa72ec151e59c82db971efebafff3e6b (MD5) Previous issue date: 2011-03-02
The increase in consumption and valorization of sheep meat is turning this ranching activity increasingly attractive and profitable. The search for technologies to reduce the loss of lambs by neonatal death is an alternative to increase production levels in sheep raising. The objective of this study was to evaluate the effects of shearing in pregnant ewe on the birth and weaning weights of lambs, as well as on the production and composition of sheep milk. The study was conducted at the Instituto Nacional de Investigación Agropecuaria - INIA, La Estanzuela, Uruguay (34° 19 S 57 40 N). Twenty Ideal breed ewes, single bearers were allocated to two treatments based on expected day of parturition, body weight and body condition. Ten ewes were shorn at 53 days of gestation and ten ewes were kept unshorn during pregnancy. Milking started seven days after parturition and was repeated weekly during 15 weeks, until weaning. Milk production of ewes shorn during gestation was 22.2% higher compared to unshorn ewes but did not change its percentage of solids. At birth lambs of shorn ewes were 1.4 kg heavier and at weaning this superiority reached 4.5 kg. The pre-parturition shearing at 53 days of gestation is a management tool that can improve the productive characteristics of sheep breed ideal.
O aumento no consumo e na valorização da carne ovina vem tornando essa atividade pecuária cada vez mais atrativa e rentável. Buscar tecnologias para diminuir a perda de cordeiros ocasionada pela morte neonatal é uma alternativa para aumentar os níveis produtivos da ovinocultura. O presente trabalho teve como objetivo estudar o efeito da tosquia em ovelhas gestantes sobre o peso ao nascimento e ao desmame de seus cordeiros, assim como a produção e a composição do leite das ovelhas. O estudo foi realizado no Instituto Nacional de Investigación Agropecuaria INIA, La Estanzuela, no Uruguai (34º 19 S 57º 40 N). Vinte ovelhas da raça Ideal, gestando cordeiros únicos foram distribuídas em dois tratamentos com base na provável data de parto, peso e condição corporal. Dez ovelhas foram tosquiadas aos 53 dias de gestação e dez ovelhas permaneceram com o velo íntegro durante a gestação. Sete dias após os partos se iniciaram as ordenhas que foram realizadas semanalmente, durante 15 semanas consecutivas até a data do desmame. A produção de leite de ovelhas tosquiadas na gestação foi 22,2% superior, mas não houve diferença no percentual de sólidos totais do leite. No momento do nascimento os filhos de ovelhas tosquiadas foram 1,4kg mais pesados e ao desmame esta superioridade atingiu 4,5kg. A tosquia pré-parto aos 53 dias de gestação é uma ferramenta de manejo que pode melhorar as características produtivas de ovinos da raça Ideal.

Com o objetivo de avaliar a susceptibilidade de ovelhas ao estresse e a relação com a produção de leite, 50 fêmeas da raça Santa Inês foram submetidas durante 2 lactações sucessivas a quatro situações de estresse (1: estresse fisiológico padrão via administração de ACTH; 2: desmame; 3: primeira ordenha; 4: mudança de ordenhador). Foram avaliadas as respostas fisiológicas, produtivas e comportamentais das ovelhas e o comportamento e ganho de peso dos cordeiros. Na 1ª lactação, os cordeiros foram desmamados com 60 dias de idade e, na 2ª de acordo com os tratamentos: 1º Grupo com 60 dias de idade e o 2º Grupo com 45 dias de idade. A maior parte das ovelhas estudadas foi considerada medianamente susceptível ao estresse, portanto não foi possível classificá-las estatisticamente, pois poucos animais foram considerados muito ou pouco susceptíveis. Após a administração de ACTH e estresse de primeira ordenha, o cortisol apresentou as maiores concentrações aos 60 minutos sendo que após cinco horas as concentrações basais foram restabelecidas. Porém, após o desmame, o cortisol permaneceu elevado, apresentando maiores valores no grupo desmamado aos 45 dias (P<0,05). A mudança de ordenhador causou estresse e promoveu posteriormente maior liberação de cortisol (P<0,05). O comportamento observado na sala de ordenha foi correlacionado positivamente com o tempo de ordenha, produção de leite e reatividade, pois alguns animais apresentaram comportamento mais agitado e reativo na ordenha, com maior frequência de coices, sobre-passos e micção. A produção de leite foi significativamente maior (P<0,05) na segunda quinzena de lactação e a duração da lactação foi estimada em 75 dias. Para ambas as lactações, os teores de sólidos totais, gordura, lactose, minerais e proteína aumentaram (P<0,05) ao longo do período. Nas duas lactações, as frequências dos comportamentos materno-filiais observados diminuíram com o passar dos dias, em função do maior interesse pela alimentação sólida em detrimento ao leite. Não houve influência da lactação e nem da idade a desmama nos pesos dos cordeiros ao parto e a desmama (P>0,05), e as ovelhas recuperaram o peso corporal algumas semanas após o parto.
With the objective to evaluate the susceptibility of ewes to stress and its relation to milk production, 50 Santa Ines females were submitted to four stressful challenges during two successive lactations (1: standard physiological stress through ACTH administration; 2: weaning; 3: first milking; 4: change of milker). In ewes, it were evaluated the physiological, productive and behavioral responses and in lambs behavioral responses and weight gain. In first lactation, lambs were weaned with 60 days of age and in the second according to the treatments: 1st Group with 60 days of age and the 2st Group with 45 days of age. Most of the studied ewes were considered median susceptible to stress, therefore, it was not possible to classify them statistically, as few animals were considered high or low susceptible. After ACTH administration and first milking stress, cortisol level presented the highest concentrations at 60 minutes and after 5 hours, basal concentrations were reestablished. However, after weaning, cortisol level remained high, presenting the greatest values in the weaned group at 45 days (P<0.05). The change of milker caused stress and later promoted higher cortisol release (P<0.05). The behavior observed in milking parlor was positively correlated with time of milking, milk production and reactivity, as some animals presented more restless behavior and reactive during milking with higher frequency of kicks, pawing and urination. Milk production was significantly higher (P<0.05) in the second fortnight of lactation and the duration of lactation was estimated in seventy five days. For both lactations, the contents of total solids, fat, lactose, minerals and protein increased (P<0.05) along the period. In both lactations, the frequencies of maternal-offspring behaviors observed decreased along the days, in function of higher interest for solid feed in detriment of milk. There was no influence of lactation and age at weaning in lambs weight at birth and at weaning (P>0.05) and ewes recovered body weight some weeks after birth.

Dissertação de Mestrado Integrado em Medicina Veterinária
A Leptospirose é uma doença emergente, sendo das zoonoses mais dispersas mundialmente apresenta uma elevada importância económica. Esta doença constitui uma das causas mais comuns de perdas embrionárias, aborto, nascimento de vitelos fracos e infertilidade em bovinos. Os bovinos são os hospedeiros de manutenção mais importantes do serovar Hardjo. Uma doença que afete os animais de produção, interfere de forma direta neste sistema, traduzindo-se numa perda económica. A presente dissertação de mestrado consistiu num estudo de caso retrospetivo, de uma exploração situada no distrito de Évora, de bovinos de raça Alentejana, explorados em regime extensivo. Apresentou como objetivos, a análise dos parâmetros reprodutivos e produtivos da vacada e a realização de uma análise do custo direto que a Leptospirose poderá ter tido na exploração. O mesmo englobou a avaliação de registos referentes a 451 fêmeas reprodutoras, 22 machos reprodutores e 1103 partos, desde o ano de 2015 até ao ano de 2020. O intervalo entre partos global aparentou ser maior na época de parição seguinte, há suspeita da entrada da Leptospirose na exploração (372+68 VS 341+40) e à época anterior a esta (351+49) (p<0,001). O índice referente à fertilidade, foi menor na época reprodutiva seguinte, ao ano de suspeita de introdução da Leptospirose na vacada (91,79% versus 88,37%). O peso ao desmame, variou ao longo dos anos em análise (p<0,001), para animais que nasceram no ano seguinte à suspeita de introdução da Leptospirose na exploração. No presente trabalho, foi também possível concluir que existe uma relação entre o mês do parto e o peso ao desmame (p<0,001). Os animais nascidos no mês de maio apresentam um peso ao desmame, significativamente menor do que animais nascidos noutros meses (p<0,05). Já os animais nascidos no mês de outubro apresentam um peso ao desmame, significativamente maior (p<0,001). Foi estimado que o custo direto que a Leptospirose apresentou na exploração em estudo foi de 11.638,08 €, tendo apresentado um custo de 38,79€ por vaca por ano. Constatou-se também que a prevenção é benéfica, perante o custo do efeito que a doença apresentou (11,57€ VS 20,95€ por cada por ano, no primeiro ano de doença).
ABSTRACT - REPRODUCTIVE AND PRODUCTIVE PARAMETERS OF AN ALENTEJANA HERD INFECTED WITH LEPTOSPIROSIS AND ANALYSIS OF THE DIRECT COSTS OF THE DISEASE - Leptospirosis is an emerging disease, being one of the most widespread zoonoses worldwide, with a high economic importance. This disease has become one of the most common causes of embryonic loss, miscarriage, birth of weak calves and infertility in cattle. Cattle are the most important maintenance hosts of serovar Hardjo. A disease that affects farm animals directly interferes in this system, resulting in an economic loss. This master’s thesis consisted of a retrospective case study, of a farm located in the district of Évora, with an Alentejana herd, farmed in an extensive regime. It presented as objectives, the analysis of the reproductive and productive parameters of the herd and the realization of an analysis of the direct cost that Leptospirosis may have had in the farm. It encompassed the evaluation of records referring to 451 breeding females, 22 breeding males and 1103 births, from the year 2015 to the year 2020. The interval between global deliveries appeared to be greater, at the time of calving following the suspicion of the entry of Leptospirosis in the herd (372+68 VS 341+40) and at the time before this (351+49) (p<0.001). The index referring to fertility was lower in the reproductive season following the year of suspected introduction of Leptospirosis in the herd (91.79% versus 88.37%). The weight at weaning varied throughout the periods evaluated (p<0.001) for animals born in the year following the suspected introduction of Leptospirosis in the herd. In the present study, it was also possible to conclude that there is a relationship between the month of delivery and the weight at weaning (p<0.001). animals born in May have a significantly lower weaning weight than animals born in other months (p<0.05). On the other hand, animals born in October have a significantly higher weaning weight (p<0.001). It was estimated that the direct cost of Leptospirosis in the farm under study was €11,638.08, with a cost of €38.79 per cow per year. It was also found that prevention is beneficial, given the cost of the effect that the disease had (11.57€ VS 20.95€ each per year, in the first year of illness).
N/A

A avaliação da eficiência produtiva da raça Mertolenga e a influência da Política Agrícola Comum desde 1986 a 2012 são as linhas de pensamento subjacentes ao longo do estudo que desenvolvemos. Deste modo analisou-se a entrada de Portugal na União Europeia - à data Comunidade Económica Europeia - e o impacto que a agricultura portuguesa sofreu numa conjuntura totalmente nova. As dificuldades de integração nos novos mercados desde cedo se fizeram sentir, devido aos stocks acumulados de alguns produtos em que Portugal era deficitário, entre os quais a carne de bovino. A bovinicultura portuguesa viu-se assim envolvida numa situação contraditória, em que necessitava de apoio e investimento para desenvolver a sua capacidade produtiva face às necessidades domésticas, mas era financiada pela Comunidade para não produzir e assim não aumentar os excedentes desta. Neste contexto, a produção de carne bovina nacional enfrentou sérias dificuldades, com os preços a descer continuamente, sendo a actividade suportada por uma série de compensações financeiras que chegaram a representar 60% das margens sobre os custos variáveis das explorações. Para avaliação da eficiência produtiva da raça Mertolenga ao longo das várias Etapas da Política Agrícola Comum (PAC) em estudo (de 1986 a 2012), analisou-se a composição do efectivo Mertolengo nacional, nomeadamente sob o ponto de vista dos aspectos estruturais como a longevidade das explorações, a dimensão dos efectivos, qual a preferência dos criadores pelos fenótipos (rosilho, malhado e vermelho) e em qual das classes de dimensão das explorações (pequena, média, regular ou grande) se situaram preferencialmente. Analisou-se também o maneio reprodutivo, a dispersão do material genético pelas explorações e a conexão entre efectivos; avaliaram-se igualmente os aspectos da eficiência zootécnica, - ponderais de crescimento - que na prática traduzem o ganho de peso vivo do animal e por consequência o seu valor comercial. Para confirmação do estudo in loco, acompanhou-se uma exploração-tipo que possuía o registo histórico do período em análise, tendo sido seleccionada uma exploração de dimensão regular (menos de 150 animais) composta por um efectivo de fenótipo vermelho, situada no concelho de Montemor-o-Novo, distrito de Évora. Todos os parâmetros foram submetidos a análise estatística descritiva e análises de variância, tendo por base a variabilidade genética da raça Mertolenga, a distribuição geográfica dos efectivos pelas 7 regiões da ACBM, tendo as análises sido enquadradas cronologicamente nas 4 etapas da PAC. Foram também efectuadas as análises de correlação que se puderam estabelecer entre parâmetros, tendo-se recorrido ao programa informático o NCSS (Number Cruncher Statistical System). A análise global com base nas percentagens de variabilidade sobre cada uma das variáveis/características, sob o efeito dos factores de variação assumidos potencialmente por nós como influenciadores, leva-nos a dizer que as Etapas da PAC não tiveram grande impacto nas alterações e sentido da eficiência de gestão técnica; ABSTRACT: Evaluation of the productive efficiency of the Mertolenga breed - The influence of the common agricultural policy from 1986 to 2012 The assessment of the productive efficiency of the Mertolenga breed and the influence of the Common Agricultural Policy from 1986 to 2012, are the underlying lines of thought throughout our study. In this way, Portugal's entry into the European Union - then European Economic Community - and the impact that Portuguese agriculture suffered in a totally new conjuncture was analyzed. Difficulties in integrating into new markets from an early age were felt due to the accumulated stocks of some of Portugal's deficit products, including beef. Portuguese cattle farming was thus involved in a contradictory situation, in which it needed support and investment to develop its productive capacity in relation to domestic needs, but was financed by the Community not to produce and thus not to increase its surpluses. In this context, domestic beef production faced serious difficulties, with prices steadily falling, and activity was supported by a series of financial offsets that came to 60% of the margins on variable farm costs. To assess the productive efficiency of the Mertolenga breed along the various Common Agricultural Policy (CAP) stages under study (from 1986 to 2012), the composition of the national Mertolenga herd was analyzed, namely from the point of view of structural aspects such as the longevity of the holdings, the size of the herds, the preference of the breeders for the phenotypes (salt-and-pepper, red spotted white and red) and in which of the size classes of the holdings (small, medium, regular and large) they were located. Reproductive management, the dispersal of genetic material among holdings and the connection between herds were also analyzed; aspects of zootechnical efficiency, - growth weights - which in practice reflect the animal's live weight gain and therefore its commercial value, were also evaluated. For confirmation of the on-site study, a standard holding of regular size (less than 150 animals) with a red phenotype herd, located in the municipality of Montemor-o-Novo, district of Évora, had the historical record of the period under review and was chosen for our study. All parameters were submitted to descriptive statistical analysis and variance analysis, based on the genetic variability of the Mertolenga breed, the geographical distribution of herds across the 7 ACBM regions and the analyzes were chronologically framed in the 4 Stages of the CAP. Correlation analyzes were also performed, which could be established between parameters, using the NCSS (Number Cruncher Statistical System) software. The overall analysis based on the percentages of variability on each of the variables/characteristics, influenced by the factors of variation assumed by us as influencers, leads us to say that the CAP Stages had no major influence on the exploitation systems, nor did they alter the efficiency of technical management.

Neste estudo pretendeu-se avaliar o efeito do sexo e do peso ao desmame sobre a performance de leitões em recria num sistema intensivo de produção. Utilizaram-se 2210 leitões com a idade média de 28 dias. Os leitões foram separados, em parques por sexo e por tipo (três tipos ligados ao peso ao desmame: leves, médios e pesados) e acompanhados até às nove semanas de idade, com controlo de pesos e ingestão de alimento por grupo/parque. O sexo dos leitões não influenciou globalmente a performance embora tendencialmente, os grupos de leitões fêmeas apresentaram um maior índice de conversão que os machos. Relativamente ao tipo, verificou-se um efeito muito significativo no desempenho global, com vantagem para os leitões pesados. Este estudo contribui para o conhecimento desta fase crítica da produção de suínos e salienta a necessidade de medidas de maneio adequadas para a obtenção dos melhores resultados produtivos; Effect of sex and weaning weight on the performance of piglets from an intensive production genotype during the first post-weaning phase Abstract: This study aimed to study the effect of sex and weaning weight on the performance of piglets during the post-weaning phase. A total of 2210 piglets with an average age of 28 days were used. The piglets were placed in separated pens, according to their sex and weight type (three types: light, medium and heavy) and followed until nine weeks of age with weight control and feed intake by pen. The piglet sex had no significant effect on the overall performance although, female piglet groups tend to present higher feed conversion rate than male piglet groups. The piglet type (weight at weaning) did influence the overall performance, with an advantage of the heavy piglets at weaning. This study contributes to the knowledge of this critical phase of pig production and highlights the need for specific management practices, in order to obtain the best productive results.

Made available in DSpace on 2014-06-11T19:26:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-23Bitstream added on 2014-06-13T20:14:38Z : No. of bitstreams: 1 barrozo_d_me_jabo.pdf: 515290 bytes, checksum: 672a5fd2bc13656f7e2aa5b2c9cfe9ba (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O objetivo foi estudar a influência da idade da vaca ao parto (IVP), da idade do animal ao sobreano (IS) e do peso ao sobreano (PS) sobre os escores de conformação (C), precocidade (P), musculatura (M) e temperamento (T) ao sobreano de animais Nelore; estimar a herdabilidade (h²) destas características, empregando-se diferentes modelos estatísticos e estimar as co-variâncias e correlações entre T e as características reprodutivas perímetro escrotal (PE), idade ao primeiro parto (IPP) e idade ao segundo parto (ISP), de bovinos Nelore. A base de dados utilizada pertence ao PAINT®, CRV Lagoa LTDA. Foram realizadas análises de regressão após a absorção do efeito de grupo de contemporâneos (GC). As estimativas de h² foram obtidas por máximaverossimilhança restrita sob um modelo animal, considerando-se o efeito genético aditivo de animal como aleatório, incluindo diferentes efeitos fixos. IVP apresentou efeito quadrático sobre P e M, segmentado quadrático-quadrático sobre C e linear sobre T. A característica C comportou-se de modo similar ao PS e P e M foram semelhantes ao ganho de peso neste período. IS e PS apresentaram efeitos quadráticos sobre C, P e M e efeito cúbico e linear, respectivamente, sobre T. Estimativas de h² foram encontradas entre 0,13 á 0,38 (C, P e M) de acordo com o modelo utilizado, enquanto para PE, IPP e ISP, as estimativas foram iguais a 0,52; 0,13 e 0,03. As correlações genéticas entre T e PE, T e IPP e T e ISP foram de 0,16; -0,04 e -0,32. As correlações estimadas entre T e as características reprodutivas foram de pequena magnitude. A seleção para os escores visuais pode trazer ganhos genéticos moderados nas características de carcaça
The aims of this study were to study the effect of age at calving (IVP), age of yearling (IS) and yearling weight (PS) on the scores of conformation (C), precocity (P), muscle (M) and temperament (T) of yearling Nellore, to estimate heritability (h ²) of these traits, using different statistical models and to estimate the covariance and correlation between T and the reproductive traits scrotal circumference (SC), age at first calf (IPP) and age at second calf (ISP). The database used belongs to the breeding program PAINT ® of CRV Lagoa LTDA. Regression analysis were performed after the absorption of the effect of contemporary group (CG). Estimates of h² were obtained by restricted maximum likelihood method under an animal model, considering the genetic effect of animal as random, with different fixed effects. IVP showed a quadratic effect on P and M, segmented quadratic-quadratic and linear on C on T, respectively. C showed similar patter as PS while P and M were similar to weight gain in this period. IS and PS showed a quadratic effect on C, P and M and cubic and linear effects, respectively, on T. The estimates of h ² ranged from 0.13 to 0.38 (C, P and M) according to the model used, whereas for PE, IPP and ISP, the estimates were equal to 0.52, 0.13 and 0, 03. Genetic correlations between T and PE, T and IPP and T and ISP were 0.16, -0.04 and -0.32. The estimated correlations between T and the reproductive traits were small. Selection applied on visual scores could bring moderate genetic gains to the carcass traits

Made available in DSpace on 2014-12-17T14:13:35Z (GMT). No. of bitstreams: 1 ClaudiaRSM_TESE.pdf: 803341 bytes, checksum: 4b80db6759e5c55e59ad18903e148c6c (MD5) Previous issue date: 2010-11-11
Investigate intrahospital and neonatal determinants associated to the weaning of very low birth weight (VLBW) infants. Methods: 119 VLBW (<1500g) infants 81 were monitored from July 2005 through August 2006, from birth to the first ambulatory visit after maternity discharge. This maternity unit uses the Kangaroo Method and the Baby Friendly Hospital Initiative. Results: Out of 119 VLBW infants monitored until discharge, 88 (75%) returned to the facility, 22 (25%) were on exclusive breastfeeding (EB) and 66 (75%) were weaned (partial breastfeeding or formula feeding). Univariate analysis found an association between weaning and lower birth weight, longer stays in the NICU and longer hospitalization times, in addition to more prolonged enteral feeding and birth weight recovery period. Logistic regression showed length of NICU stay as being the main determinant of weaning. Conclusion: The negative repercussion on EB of an extended stay in the NICU is a significant challenge for health professionals to provide more adequate nutrition to VLBW infants
O leite materno ? o alimento recomendado para rec?m-nascidos de risco, no entanto, baixas taxas de aleitamento materno s?o observadas entre eles na alta hospitalar, sobretudo para aqueles de muito baixo peso ao nascer. A identifica??o dos fatores de risco associados ao insucesso dessa pr?tica pode auxiliar na ado??o de novas condutas pela equipe multiprofissional que os assiste. Esse estudo tem por objetivo identificar determinantes maternos e neonatais intra-hospitalares associados ao desmame de rec?m-nascidos de muito baixo peso ao nascer (RNMBP) na primeira consulta ambulatorial ap?s a alta da maternidade. Todos os RNMBP (PN<1500g) nascidos de julho/2005 a agosto/2006 foram acompanhados do nascimento ao primeiro retorno ambulatorial em at? sete dias ap?s alta de Maternidade que adota o M?todo Canguru e a Iniciativa Hospital Amigo da Crian?a. Dos 119 RNMBP acompanhados at? a alta, 88 retornaram ao ambulat?rio. Destes, 22 (25%) encontravam-se em aleitamento materno exclusivo (grupo AME) e 66 (75%) j? haviam introduzido f?rmula infantil na dieta, sendo 63 (71,5%) associado ao uso de leite materno e 03 (3,5%) em uso exclusivo da f?rmula (grupo desmame). Na an?lise univariada, associaram-se ao grupo desmame (f?rmula exclusiva ou f?rmula+leite materno) o menor peso ao nascer e os maiores tempos de perman?ncia na UTI neonatal (UTIN), de interna??o total, de dieta enteral e para recupera??o do peso de nascimento. A regress?o log?stica demonstrou ser o tempo prolongado de interna??o na UTIN o principal determinante da introdu??o da f?rmula alimentar para alimenta??o dos RNMBP logo ap?s a alta da maternidade. Conclui-se que houve alto percentual de introdu??o de f?rmula no domic?lio, observada em consulta de retorno em at? 07 dias, e consequentemente baixas taxas de aleitamento materno exclusivo (AME). A longa perman?ncia em UTIN representou o principal determinante de risco sobre o AME e consiste um grande viii desafio para os profissionais de sa?de proporcionarem a alimenta??o mais adequada para os RNMBP. A atua??o conjunta de m?dicos neonatologistas, nutr?logo, nutricionistas, assistentes sociais, psic?logos e equipes de enfermagem na assist?ncia dos rec?mnascidos de risco na Unidade de Terapia Neonatal permitiu o trabalho em equipe interdisciplinar, objetivo primordial do Programa de P?s-Gradua??o em Ci?ncias da Sa?de, trazendo viv?ncias enriquecedoras que s?o essenciais ao bom desempenho profissional e a relev?ncia de um atendimento mais humanizado, colaborativo e compartilhado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The objective of the present study was to evaluate in Charolais and Nellore calves and their crossbred F1 the genetic (crossbreed system, genetic group and heterotic and racial additive effects) and environmental effects influence on weight at birth, adjusted weight for 205, 365, 550 and 730 days of age, and daily average gain of weight from birth to 205, from 205 to 365, from 365 to 550, and from 550 to 730 days of age. Four hundred fifty eight males bovines, all belonging to the same herd, born among the year of 1985 and 1995, from the continuous rotary crossbreed between Charolais and Nellore races were used. The animals were distributed per crossbreed system, defined (Charolais and Nellore) and crossbreed (½ Charolais ½Nellore and ½Nellore ½Charolais). The environmental effects analyzed were cow age at calving (3 to 12 years) and calves birth month (September to December). The data were submitted to variance analysis, f test and t Student test at 5% of significance. The heterotic and racial additive effects were obtained by contrast. Charolais calves presented higher performance in pre- weaning than Nellore, being the individual racial additive genetic effect positive. The maternal racial additive genetic effect influenced just weight at birth (5.26 kg). The heterosis was significant for weaning weight (11.0 kg) and weight gain from birth to weaning (0.052 kg/day). The crossbreed exceeded Nellore in all characteristics and was similar to Charolais for weaning weight. The weight at birth increased with the increasing in cow age at calving, while for the others characteristics of pre- weaning, the influence of genotype x environmental interaction was more evident for defined than crossbreed. The birth month influenced the weight at birth and the gain weight from birth to weaning, with maximum values for born in the months of October (34 kg) and December (0.572 kg/day), respectively. Charolais bovines are superior to Nellore race for performance characteristics in post- weaning, being the individual racial additive genetics effects positives and influence the weight and weight gain from 205 to 365 and from 550 to 730 days of age. Crossbred steers are superior in relation to defined for evaluated weights in post weaning besides of better performance in weight gain from 205 to 365 and from 365 to 550 days of age. The genotype x environmental interaction influenced the weights at year, at yearling and the daily average weight gain from yearling to two years old. The birth month influenced weight at year, and the daily average weight gains from weaning to one year old and from one year old to yearling, with maximum weights for the ones that were born in October, September and December, respectively.
O objetivo do presente estudo foi avaliar em bezerros Charolês, Nelore e suas cruzas F1, a influência dos efeitos genéticos (sistema de acasalamento, grupo genético e efeitos aditivos raciais e heterótico) e ambientais sobre o peso ao nascer, pesos ajustados para 205, 365, 550 e 730 dias de idade, e o ganho de peso médio diário do nascimento aos 205, 205 aos 365, 365 aos 550 e 550 aos 730 dias de idade. Foram utilizados os dados de 458 bovinos machos, do mesmo rebanho, nascidos entre os anos de 1985 a 1995, oriundos do cruzamento rotativo contínuo entre as raças Charolês e Nelore. Os animais foram distribuídos por sistema de acasalamento, definidos (Charolês e Nelore) e cruzados (½ Charolês ½ Nelore e ½ Nelore ½ Charolês). Os efeitos ambientais analisados foram a idade da vaca ao parto (3 a 12 anos) e mês de nascimento dos bezerros (setembro a dezembro). Os dados foram submetidos à análise de variância, teste F, e teste t de Student a 5% de significância. Efeitos aditivos raciais e heteróticos foram obtidos por contraste. Bezerros Charolês apresentaram maior desempenho no pré-desmame do que os Nelore, sendo os efeitos genéticos aditivos raciais individuais positivos. O efeito genético aditivo racial materno influenciou apenas o peso ao nascer (5,26 kg). A heterose foi significativa para peso ao desmame (11,0 kg) e ganho de peso do nascimento ao desmame (0,052 kg/dia). Os cruzados superaram os Nelore em todas as características e foram similares aos Charolês para peso ao desmame. O peso ao nascer incrementou com o aumento na idade da vaca ao parto, enquanto que para as demais características do pré-desmame, a influência da interação genótipo x ambiente foi mais evidente para os definidos do que para os cruzados. O mês de nascimento influenciou o peso ao nascer e o ganho de peso do nascimento ao desmame, com valores máximos para os nascidos nos meses de outubro (34 kg) e dezembro (0,572 kg/dia), respectivamente. Bovinos Charolês são superiores aos da raça Nelore para as características de desempenho no pós-desmame, sendo que os efeitos genéticos aditivos raciais individuais são positivos e influenciam os pesos e ganhos de peso dos 205 aos 365 e 550 aos 730 dias de idade. Os novilhos cruzados são superiores em relação aos definidos para os pesos avaliados no pós-desmame, além do melhor desempenho nos ganhos de peso dos 205 aos 365 e dos 365 aos 550 dias de idade. A interação genótipo x ambiente influenciou os pesos ao ano, ao sobreano e o ganho de peso médio diário do sobreano aos dois anos de idade. O mês de nascimento influenciou o peso ao ano, e os ganhos de peso médio diário do desmame ao ano e de um ano ao sobreano, com pesos máximos para os nascidos em outubro, setembro e dezembro, respectivamente.

There is little evidence that the productivity of New Zealand beef herds has improved over time. Data from the NZ Meat and Wool Board’s Economic Service (2006) suggest that the average national calving percentage has declined over the last two decades. During the same period cattle carcass weights have increased but so too has the average cow live-weight which has resulted in increased maintenance costs of the cow herds. It is unclear whether production efficiency in the industry has improved or declined over time. The aim of this research was to develop means of improving productivity in commercial beef herds through practical methods of performance recording. The objectives were firstly to establish current management practices in commercial herds and secondly to develop an objective system for cow selection and culling which would have practical application in commercial herds. Beef management survey Ninety two commercial beef producers with more than 100 breeding cows from the greater Canterbury region of New Zealand were surveyed. Pasture control was the main reason given for owning a beef herd. Size and conformation were the main selection criteria for choosing replacement heifers and bulls. Over 80% of herds retained their own heifers as replacements and >60% mated yearling heifers to first calve at two years of age. Fertility was poor in the surveyed herds. In-calf rates at pregnancy testing averaged 88% for maiden heifers, 92% for rising second calvers and 93% for mixed age (m.a.) cows. There was no significant difference between in-calf rates of maiden heifers mated to first calve at two or three years of age; nor was there any significant difference between the re-breeding success of the two groups. Heifers mated at least one week earlier than m.a. cows, achieved a re-breeding success 4.7% greater (P<.01) than those mated at the same time. Reasons for cows not weaning a calf included wet dry (9.3% of pregnant cows wintered), pregnancy tested not-in-calf (7.4%) and dam death (2.6%). Only 87.9% of pregnant females wintered weaned a calf (89.4% of m.a. cows and 84.9% of heifers). Reasons why cows exited the herds included diagnosed empty (37.2% of all exits), involuntary culls (25.4%), sold wet dry (16.2%), deaths (13.1%) and poor calf production (5.1%). Vaccination was infrequent with clostridial vaccines the most common in m.a. cows (15.2%) and in calves (40.7%); vaccination against Leptospirosis was much less common. Very few of the surveyed farms used any system of performance recording; as a result there was very little performance-based selection or culling practiced. Evaluation of alternative measures of cow productivity Data from four performance recording beef herds were used to compare alternative measures of cow productivity with the industry standard which is calf weaning weight adjusted for sex (SOC) and age of calf and age of dam (AOD), i.e. the “200 day weight.” None of the alternative measures evaluated required knowledge of calving date and all were relatively easily obtainable in extensively managed beef herds. The assessment of cows was based not on their estimated breeding values but instead on their most probable producing ability which, as the sum of all of the permanent, repeatable aspects of the calf-rearing ability of the cow, explains considerably more of the variance of weaning weight than does breeding value alone. SOC and AOD-adjusted marking weight, weaning weight and average daily gain (ADG) between marking and weaning were the traits mostly highly correlated with the 200d wt of calves (r = 0.68, 0.90 and 0.74. respectively). An Extensively- Grazed-Cow-Weaning-Index of these three indicator traits was found to be more highly correlated than any of the individual traits on their own (r = 0.94). Index weights for the three indicator traits were calculated within each herd and then those within-herd index weights were regressed on readily obtainable herd descriptive variables to obtain a regression equation that could predict index weights for any herd. When the model was applied to data from two additional herd years not included in the original model, the EGCW Index was highly correlated with the 200d weights (r>0.90). Performance-based culling of previously unselected commercial beef herds based on the EGCW Index will result in improved productivity due to the moderately high repeatability of calf weaning weight. Objective data from extensively grazed commercial herds will also make possible the use of commercial herd data in genetic evaluations of herd sires.

La raça Parda de Montaña és una raça d'aptitud càrnica amb molt bona capacitat maternal fortament adaptada a les condicions extremes dels sistemes muntanyosos. Les dades utilitzades en els anàlisis d'aquesta tesi es van obtenir de les bases de dades de la associació ARAPARDA i de la finca experimental "La Garcipollera". En el capítol I s'analitza la component genètica i ambiental del caràcter facilitat de part utilitzant un model normal i un model llindar. En el capítol II s'analitza la component genètica i ambiental dels caràcters pes al naixement, pes als 90 dies, pes al deslletament, pes adult i producció de llet. En el capítol III s'estudia la relació entre els efectes de maneig: època de naixement, taxa de maduresa de la vaca a la primera cobrició, edat al primer part i raça, amb la productivitat i la longevitat de la vaca. En el capítol IV es relaciona la productivitat i longevitat obtinguda en el capítol anterior amb els valors genètics de les vaques segons el seu tipus genètic.
La raza Parda de Montaña es una raza de aptitud cárnica con muy buena capacidad maternal fuertemente adaptada a las condiciones extremas de los sistemas montañosos. Los datos utilizados en los análisis de esta tesis se obtuvieron de las bases de datos de la asociación ARAPARDA y de la finca experimental "La Garcipollera". En el capítulo I se analiza la componente genética y ambiental del carácter facilidad de parto usando un modelo normal y un modelo umbral. En el capítulo II se analiza la componente genética y ambiental de los caracteres peso al nacimiento, peso a los 90 días, peso al destete, peso adulto y producción de leche. En el capítulo III se estudia la relación entre los efectos de manejo: época de nacimiento, tasa de madurez de la vaca en la primera cubrición, edad del primer parto, y raza, con la productividad y la longevidad de la vaca. En el capítulo IV se relaciona la longevidad y la productividad obtenida en el capítulo anterior con los valores genéticos de las vacas según su tipo genéico.
The Parda de Montaña is a breed cattle breed with a very good maternal ability and strongly adapted to the extreme conditions of mountain systems. The data used in the analyzes of this thesis were obtained from the databases of the ARAPARDA association and the "La Garcipollera" experimental farm. In Chapter I, the genetic and environmental components of the calving ease were analyzed using a normal model and a threshold model. Chapter II discusses the genetic and environmental components of birth weight, weight at 90 days, weaning weight, nature weight and milk yield. Chapter III examines the relationship between management effects: the season of birth, the maturity rate of first cow service, the age at first calving, and breed, with the productivity and longevity of the cow. Chapter IV relates the longevity and productivity obtained in the previous chapter to the genetic values of cows according to their genetic type.

Made available in DSpace on 2014-08-20T14:38:04Z (GMT). No. of bitstreams: 1 dissertacao_alvaro_carlos_menezes_arteche.pdf: 1268541 bytes, checksum: 48cb8939395a534c09b30fdb0ec17ef9 (MD5) Previous issue date: 2011-11-21
This study analyzed, by reaction to indirect immunofluorescence and individual weighting, the levels of protection and weight-gain in beef calves from birth to the age of eight month, which received two doses of vaccine against tick fever and were maintained free from ticks, compared to naturally infested calves in extensive management conditions with continuous grazing in a rural property situated in the municipality of Santana do Livramento Espinilho / RS. Two groups were randomly gathered, n=30, from which Group I (test) was kept free from ticks from birth to weaning and received two doses of the attenuated, trivalent, refrigerated vaccine against tick fever. Groupe II (control) followed the property s traditional management, which reflects the one used in the region, allowing the tick infestation by the animals. Weight control was accomplished in the first day (d0) and in the last day of the experiment (d180). The serology revealed that 100% of the vaccinated animals presented titles equal to 1:5120 for the three parasites Anaplasma marginale, Babesia bovis e Babesia bigemina (p≤0,025), whereas in the control group the highest titles were 1:2560 in four animals for A. marginale, 1:1280 in four animals for B. bovis and 1:1280 in two animals for B. bigemina (p≤ 0,025). Group I got a mean weight-gain of 30,5 kg more than the control group at the end of the experiment (p≤0,025). The results obtained show that keeping animals free from tick, from birth to weaning, and maintaining them vaccinated against tick fever is safer, more efficient and economically and technically more advantageous than the traditional management system carrapateamento (natural tick infestation).
Avaliaram-se, pela reação de imunofluorescência indireta (RIFI) e de pesagens individuais, os níveis de proteção e ganho de peso de terneiros de corte do nascimento ao desmame com oito meses de idade que receberam duas doses de vacina contra tristeza bovina e foram mantidos livres de carrapatos em comparação a terneiros naturalmente infestados em condições de manejo extensivo com pastoreio contínuo em propriedade rural localizada no município de Santana do Livramento-Espinilho/RS. Formaram-se dois grupos aleatóriamente, n=30, sendo o GRUPO I (teste) mantido livre de carrapatos desde o nascimento até o desmame e com duas doses da vacina atenuada, trivalente e refrigerada contra tristeza bovina. O GRUPO II, controle, seguiu o manejo tradicional da propriedade, que reflete o da região, permitindo que os animais fossem infestados por carrapatos. As pesagens foram realizadas no primeiro dia do experimento (d0) e no último dia do experimento (d180). A sorologia revelou que 100% dos animais vacinados apresentaram títulos maiores ou iguais a 1:5120 para os três parasitos Anaplasma marginale, Babesia bovis e Babesia bigemina (p≤0,025) enquanto que no grupo controle os títulos máximos foram 1:2560 em quatro animais para A. marginale, 1:1280 em quatro animais para B. bovis e 1:1280 em dois animais para B. bigemina. Houve diferença significativa entre os dois grupos (p≤0,025). O grupo I obteve 30,5 Kg a mais de ganho médio de peso que o grupo controle no final do experimento (p≤0,025). Com os resultados obtidos, conclui-se que é mais eficiente, seguro e vantajoso econômica e tecnicamente manter os animais livres de carrapatos, desde o nascimento até o desmame, e vacinados contra tristeza bovina, do que com o manejo tradicional carrapateamento .

O objetivo deste estudo foi avaliar a influência do número de leitões paridos e desmamados no primeiro parto, das reservas corporais ao parto e a perda das reservas corporais durante a lactação sobre a produção de leitões no segundo parto. Foram analisadas 1222 fêmeas que chegaram ao segundo parto sem interrupções como retorno ao estro, abortamento ou vazias ao parto. Foram medidos o peso corporal, espessura de toucinho (ET) e escore corporal visual (ECV), no máximo 24 horas pós-parto e no dia do desmame. Foram calculados a gordura e a proteína corporal ao parto e ao desmame para posteriormente serem obtidos os valores com relação às perdas destas reservas. O total de leitões nascidos no primeiro e no segundo partos e o número de leitões desmamados foram analisados de acordo com as características corporais e produtivas das fêmeas no primeiro parto e primeiro desmame. O tamanho de leitegada no primeiro e no segundo partos foram, respectivamente 12,4 leitões e o de 9,7 leitões nascidos totais. Na média as fêmeas apresentaram redução de 18,6 kg (9%) de peso corporal, 3,1mm de ET e 0,8 de ECV durante a lactação. O tamanho da leitegada no segundo parto não diferiu entre as classes das variáveis, peso, ET, ECV, gordura e proteína corporal no primeiro parto (P>0,05). As fêmeas com peso acima de 178kg, ET (≥16), ECV (≥3,0) e gordura corporal (≥21%) ao desmame tiveram maior leitegada no segundo parto e menor diferença no número de nascidos entre o primeiro e segundo parto (P<0,05). Fêmeas com maior percentual de proteína corporal ao desmame (≥15%) tiveram maior número de leitões nascidos na segunda leitegada. Houve maior diminuição no tamanho da segunda leitegada nas fêmeas com perdas de peso corporal acima de 10% (P<0,05). Perdas de proteína ou de gordura corporal acima de 10% e de 23%, respectivamente implicaram na maior diminuição no número de leitões nascidos no segundo parto (P<0,05). A perda de reservas corporais durante a lactação de primíparas influencia a redução do tamanho da leitegada no segundo parto.
The aim of this study was to evaluate the influence of body reserves at farrowing and the corporal reserves losses during the first lactation on the second litter size. A number of 1222 females that reached the second parity without interruptions as return to estrus, abortion or failing to farrow were analyzed. Measurements of body weight, backfat thickness (BT) and corporal condition (CC) were taken within 24-hours after farrowing and on the weaning day. Sow body fat and protein mass, at first farrowing and first weaning, were calculated and the values of these reserves losses were estimated. The total piglets at first and second farrowing and the number of weaned piglets were analyzed according to the females corporal and productive characteristics at first farrowing and first weaning.Litter size at first and second farrowing were respectively 12.4 and 9.7 total born piglets. In the average, the females demonstrated a reduction of 18.6 kg (9%) in body weight, 3.1mm BT and 0.8 CC during lactation. Second litter size did not differ between the categories body weight, BT, CC, body fat and body protein at first farrowing (P>0.05). Females with more than 178kg, BT (≥16), ECV (≥3.0) and body fat (≥21%) at weaning had largest second litters and less differences in the number of piglets born between first and second farrowing (P<0.05). Sow body protein mass at weaning (≥15%) had a higher effect on the number of piglets produced in the second litter. Females with weight losses during lactation above 10% showed the greatest reduction in second litter size (P<0.05). Protein or fat mass losses above 10% and 23%, respectively resulted in a high reduction in the number of total born piglets in second litter (P<0.05).Looses of corporal reserves during the first lactation influences the reduction in the second litter size.

Dissertação (mestrado) - Pontifícia Universidade Católica do Paraná, São José dos Pinhais, 2010
Inclui bibliografias
O trabalho discute um dos principais problemas relacionados aos baixos índices da pecuária nacional, o anestro pós-parto de bovinos de corte. O anestro puerperal nos bovinos ocorre em função de uma série de variáveis, sendo os aspectos ligados à nutrição
The work aimed discusses the mains problems associated to the low fertility rates of national livestock, being post partum anestrus in beef cattle. The postpartum anestrus in bovines comes from several variables, being related to nutrition and breastfeedi

Испитивање повезаности особина из перформанс теста назимица савеличином легла крмача, обављено је на седам генотипова животиња (чистихраса: дански ландрас, холандски ландрас, немачки ландрас, шведски ландрас ивелики јоркшир и програмских мелеза: мелеза чија је мајка ландрас и мелеза чијаје мајка велики јоркшир).Фенотипска повезаност особина из перформанс теста (ектеријер, маса накрају теста, старост на крају теста, дневни прираст у тесту, дебљина сланинеу слабинском делу, дебљина сланине у леђном делу, дубина МЛД-а, број легла,приплодна вредност назимица процењена селекцијским индексом и проценат месау трупу) и два основна репродуктивна параметра (број живорођене прасади и бројзалучене прасади), статистички је анализирана софтверским пакетом „Статистика13“ и „SPSS верзија 23“. Испитано је постојање/непостојање утицаја свакепојединaчне особине из перформанс теста на репродуктивне особинеНије утврђена општа повезаност свих особина перформанс теста ирепродуктивних особинаАнализиране особине показале су велику зависност од генотипаиспитиваних животиња.
Ispitivanje povezanosti osobina iz performans testa nazimica saveličinom legla krmača, obavljeno je na sedam genotipova životinja (čistihrasa: danski landras, holandski landras, nemački landras, švedski landras iveliki jorkšir i programskih meleza: meleza čija je majka landras i meleza čijaje majka veliki jorkšir).Fenotipska povezanost osobina iz performans testa (ekterijer, masa nakraju testa, starost na kraju testa, dnevni prirast u testu, debljina slanineu slabinskom delu, debljina slanine u leđnom delu, dubina MLD-a, broj legla,priplodna vrednost nazimica procenjena selekcijskim indeksom i procenat mesau trupu) i dva osnovna reproduktivna parametra (broj živorođene prasadi i brojzalučene prasadi), statistički je analizirana softverskim paketom „Statistika13“ i „SPSS verzija 23“. Ispitano je postojanje/nepostojanje uticaja svakepojedinačne osobine iz performans testa na reproduktivne osobineNije utvrđena opšta povezanost svih osobina performans testa ireproduktivnih osobinaAnalizirane osobine pokazale su veliku zavisnost od genotipaispitivanih životinja.

碩士
國立中興大學
畜產學系
94
This study has two purposes: the first is to examine the effect of birth season on growth of goat kids by comparing the feeding intakes, average body weight gain and blood constituents in goat kids born out of birth season using artificial controlled photoperiod mating in anestrus season and those born in birth season during the natural photoperiod. The second is to examine the effect of weaning at the 7th or the 9th week on the average body weight gain and blood constituents of goat kids; then to compare the effect of both different birth season and weaning age together. Seventeen kids born between August and October and twenty kids born between December and June were used in this experiment. During the experimental period, intake of water, milk replacer, concentrate and alfafa hay, and also the body weight of kids at 1-13 weeks of age were recorded in order to calculate body weight gain and feed efficiency. Blood samples were collected weekly from 6 to 13 weeks of age to analyze packed cell volume (PCV), the concentration of serum total protein, sodium, potassium and chloride. The serum protein bands of kids at 8 and 13 weeks of age were separated and quantified by agarose electrophoresis. The result shows that the higher average birth weight of kids born in the birth season, where the average birth weight was 3.27 kg; whereas those born out of the birth season was 2.67 kg ( P < 0.01), but there was no significant difference after the 5th week. Body weight gain of kids born in the birth season was higher than those born out of the birth season at 5, 6 and 7 weeks of age (P < 0.05). The PCV of kids born out of birth season was higher than those born in the birth season at 6, 9, 10, 11 and 13 weeks of age (P < 0.05). The concentration of serum total protein, γ-globulin and chloride of kids born in the birth season was higher than those born out of the birth season at 13 weeks of age (P < 0.05). The concentration of serum albumin, sodium and potassium, and A/G ratio of kids born out of the birth season was higher than those born in the birth season. In the different weaning age experiment, the average body weight of the kids weaned at 7 weeks of age was lower than these of the kids weaned at 9 weeks (P < 0.05) at 8 weeks of age. However, the body weight gain of kids weaned at 9 weeks was higher than that of those weaned at 7 weeks of age at both 7 and 8 weeks of age (P < 0.01). The PCV of kids weaned at 9 weeks was higher than those of 7 weeks at 10 and 11 weeks of age (P < 0.05). There was no significant difference of concentration of serum total protein, sodium and potassium between 7 and 9 week weaned kids. At 8 weeks of age, the concentration of chloride of kids weaned at 7 weeks was higher than those at 9 weeks (P < 0.05). In the kids weaned at 7 weeks, body weight, body weight gain, PCV and serum sodium concentration of kids born out of the birth season was higher than of those born in the birth season (P < 0.05). In the kids weaned at 9 weeks, the concentration of serum chloride of those born in the birth season was higher than those born out of the birth season (P < 0.05). In conclusion, kids born out of the birth season due to artificial controlled photoperiod mating in anestrus season are born lighter, but this does not affect the growth of kids. Growth performance and blood constituents of kids weaned at 7 weeks of age are no different from those weaned at 9 weeks, and the effect of different weaning age on kids born out of the birth season seems less than those born in the birth season. So artificial controlled photoperiod mating, and weaning kids somewhat ahead of age are both feasible methods of management.

The impact of within-litter weight variation on the productivity of pig enterprises is poorly understood. The objective of the study was to determine the effect of within-litter birth weight variation on litter performance at three weeks of age and at weaning. The study was conducted using records from 1 788 litters, collected between January 1998 and September 2010, from a pig herd at the Agricultural Research Council (ARC), Irene. The records consisted of piglet identity, breed of sow, breed of boar, parity number, date of farrowing, number of piglets born alive (NBA), individual piglet weight at birth, three weeks and at weaning. From these records, mean birth weight (MBWT), litter weight at birth (TBWT), within-litter birth weight coefficient of variation (CVB), minimum birth weight (MinB) and maximum birth weight (MaxB) were calculated. Mean weight at three weeks (MWTT), litter weight at three weeks (LWTT), within-litter weight coefficient of variation at three weeks (CVT), percent survival to three weeks (SURVT), mean litter weaning weight (MWWT), litter weight at weaning (LWWT), within-litter weaning weight coefficient of variation (CVW) and percent survival at weaning (SURVW) were computed as derivatives. The factors affecting CVB were analysed using the General Linear Model procedures (SAS, 2008). For the relationships between CVB and litter performance at three weeks and weaning, PROC STEPWISE was used. The PROC REG (SAS, 2008) was then used to test whether the relationships between CVB and CVT, SURVT, MWTT, LWTT, CVW, SURVW, MWWT, LWWT and LWWT. Multiparous sows farrowed litters with higher (P<0.05) CVB than gilts. The litter weight (TBWT) and NBA, fitted as covariates, also affected (P<0.05) CVB. The correlation between CVB and NBA was 0.30. The CVB had a linear relationship (P<0.05) with SURVT (SURVT = 83.21 - 0.20 CVB), CVT (CVT = 16.71 + 0.50 CVB), SURV (SURW = 87.9 – 0.04CVB) and CVW (CVW= 15.8 + 0.5CVB). An increase of CVT with CVB depended on parity (P<0.05). The rate of increase of CVT with CVB was highest in Parity 1 (b=0.41) followed by Parity 2 (b=0.36) then middle aged (Parity 3-5) sows (b=0.32). The CVB had no effect on MWTT, LWTT, MWWT and LWWT (P>0.05). The CVB was shown to be an important determinant of SURVT and SURVW. A uniform litter at birth is likely to lead to a homogenous litter at three weeks and weaning, thereby reducing costs of production. Pig producers should, therefore aim at producing homogenous litters at birth.
Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008.
Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6482. Adviser: Mike Ellis. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

碩士
國立屏東科技大學
熱帶農業暨國際合作系
105
In a bid to achieve food security with the increasing world population, commercial pig producers aim for high lean content or increase number of surviving piglets to slaughter in a farm. The abrupt changes experienced by piglets in the modern weaning practice jeopardise production performance as it leads to growth checks or even death in extreme cases. Post-weaning growth check, caused by reduced or zero feed intake at weaning, is an economic and welfare concern. Following inconsistent conclusions from available literature pertaining effects of weaning weights on growth performance in piglets at weaning, it was hypothesised that weaning weight variation within a litter has high influence on growth check intensity. Relative growth check intensity in this study was defined as the degree of reduction in relative average daily gain (ADG) on day 2 post-weaning as a percentage of relative ADG of the last week pre-weaning. Relative ADG was defined as daily weight gain (grams/24hrs) expressed as percentage of initial bodyweight (kg). The objective of this research was to verify the effects of weaning weights on growth check intensity during the first week post-weaning. Three experiments were conducted, using a total of 56 weaned piglets, to determine any significant differences in post-weaning growth check intensity between heavy and light piglets. Using 12 healthy piglets which were crosses of Landrace, Large White and Duroc, weaned at 28 days, the first experiment investigated the effects of body energy reserves on growth check of pre-weaning. General behaviour for energy balance was observed in heavy (7.65 ± 0.38 kg) and light (6.47 ± 0.42 kg). A total of 5 males and 7 females were distributed within the 2 groups of heavy and light piglets. Animal growth performance was expressed in terms of relative ADG and relative growth check intensity. Heavy piglets significantly had high relative ADG (p < 0.05). Body energy reserves were determined by measuring relative blood glucose concentration. Relative blood glucose concentration was expressed as percentage of initial glucose concentration. There were significant differences (p < 0.05) in blood glucose concentration with less glucose concentration in heavy piglets from day 0 – 4. Blood glucose was not sufficient to explain body energy reserves, so behaviour for body energy balance was examined. Weaning weights affected energy intake (p < 0.01), conservation (p < 0.001) and expenditure (p < 0.05) frequencies but not energy elimination (p > 0.05. Body size affected growth check intensity with heavy piglets experiencing low growth check intensity than light piglets. As another factor thought to contribute to growth check intensity, instinctive learning ability to eat after weaning was assessed in experiment 2 by using 12 piglets grouped into heavy (11.10 ± 0.32 kg) and light (7.64 ± 0.73 kg) experimental groups. Instinctive learning behaviour was observed for 7 days post-weaning in 12 continuous hours per day (7:00a.m. - 7:00p.m.). In each group there were 3 castrated males and 3 females to make 6 animals per group. Again, relative ADG and growth check intensity were used to estimate animal growth performance. There were no significant differences (p > 0.05) in both relative ADG and relative growth check intensity between heavy and light piglets weaned at 35 days of age. However, heavy piglets significantly had high feed intake (p < 0.001) because they needed more energy to maintain their body weight. Heavy piglets significantly had shorter time to start eating (p < 0.01), allowing them to have significantly high eating frequency (p < 0.01) yielding to significantly high eating time and shorter meal intervals per given 12-hr day. Thus, weaning weights affected instinctive learning ability with heavy piglets being better learners. This proved that even without transition, piglets can learn to cope with weaning stress in a given environment. Effects of weaning weights on conditioning learning ability to eat was assessed by conditioning piglets to creep feeding in experiment 3. This experiment used principles of classical conditioning. In a 2 x 2 factorial design, 32 Meinung piglets with 17 castrated males and 15 females were used in this study. Grouping by weaning weights was used as main factor to form heavy and light piglet groups. Two creep feeding levels (with or without creep feed) was used as a within group factor. ‘Without creep feed’ piglets were control groups that were not conditioned for hourly creep feeding. At 28 days of age ‘with creep feed’ piglets were conditioned to eat creep feed at hourly intervals during the last week pre-weaning. At weaning (35 days of age), all four experimental groups were tested on feeding behaviour highlighting latency to start eating, meal duration, daily eating duration and eating frequency. Each trial lasted for 0.5hr with 1hr feed withdrawal periods making 5 trials per day. Weaning weights alone had no significant (p > 0.05) effects on relative ADG and growth check intensity. Creep feed conditioned piglets did not suffer growth check. Within group effects, weaning weights significantly affected growth check intensity in which light pigs had high growth check intensity (p < 0.001) because they were not habituated to creep feeding and low body energy reserves. Increase in weaning weights reduced growth check intensity. Heavier body weights improved conditional reflex learning ability in piglets. A feeding regime offering creep feed gives piglets the possibility to cope better with transition at weaning.

Thesis (M.A. Agricultural Management (Animal Production)) -- University of Limpopo, 2020
The Nguni is indigenous multi-purpose cattle breed that plays an important role in both commercial and communal farming systems in South Africa (SA). Unfortunately, the breed is currently under threat of diminishing due to farmers’ preference for exotic breeds and cross breeding. In recognition of the above, the Industrial Development Corporation, the Mpumalanga Department of Agriculture, Rural Development, Land and Environmental Affairs and the University of Limpopo established the Nguni cattle breed preservation project. In this project, a herd of 30 Nguni heifers and 1 bull were allocated to 34 Communal Property Associations (CPA) and 40 private farming enterprises each. With its three distinct ecological zones (High, Mid and Low-veld), the Mpumalanga province poses a challenge to the Nguni preservation project since cattle have to adapt to different ecological zones in order to grow and reproduce efficiently. Knowledge of cattle herd productivity improves the understanding of the functional attributes and is useful in determining the constraints and the potential of communal beef cattle production systems. Significant differences between ecological zones were observed for age at first calving, weaning rate, calves’ birth weight and calves’ weaning weight (p < 0.05). Calving of heifers in the Mid-veld zone occurred earlier (24 months) on both ownership types compared to Highveld (28.09 months for private and 26.00 for CPA) and the Lowveld (28.35 months for both ownerships). Nguni cattle on the Highveld performed better in terms of weaning rate under both private and CPA ownerships, where the weaning rate were 93% and 80%, respectively. Calves birth weight was lower in both ownership types in the Midveld zone (22.17 kg), whereas in the CPA, the Lowveld zone had higher calves birth weights (26.80 kg). In the private ownership, the highest calves’ birth weight (25.35 kg) was on the Highveld. The calves weaning weight were significantly higher (p < 0.05) on Highveld in private ownership (190.16 kg) and lowest (160.39 kg) in the Midveld zone. For the CPA, the highest calves weaning weight was also on the Highveld (187.55) and lowest on Midveld (167.50 kg). A full range of backup services that are offered to the communities by stakeholders in the form of a beef package that includes veld and pasture management, nutrition management, beef performance, animal recording keeping, genetic evaluation and animal health management program needs thorough attention.

The full text of this thesis/dissertation is not available online. Please contact us if you need access. Read the abstract in the section 00front of this document.
Dissertation (M Inst Agrar (Animal Production))--University of Pretoria, 2006.
Animal and Wildlife Sciences
unrestricted

Thesis (Ph.D. (Animal Production)) --University of Limpopo, 2018
Pigs are of high economic importance, especially among the smallholder pig farmers as they contribute to human nutrition, food security, poverty alleviation, enhanced livelihood and creation of employment for the rural community. However, reproductive inefficiency is the main limiting factor due to inaccessibility to superior germplasm. Therefore, advances in reproductive technologies such as oestrus synchronization and artificial insemination (AI) offers unprecedented opportunities for livestock improvement for smallholder pig farmers. The first objective determined the status of pig productivity in smallholder farms of Gauteng Province prior to the introduction of advanced reproductive technologies (ARTs). The population was divided into four strata, namely West Rand, Ekurhuleni, Tshwane and Sedibeng district municipalities. A proportional stratified random sampling procedure was used to select 71 smallholder pig farmers with the assistance of extension officers from Gauteng Department of Agriculture and Rural Development (GDARD). The majority of the respondents were males (67%) and were above 50 years of age (67%), whilst 56% of the respondents had high school education. Majority of the respondents privately owned the farms (62%) and the farm infrastructure had facilities with low cost housing and modern facilities. Additionally, 47% of the respondents fed their pigs with feed swill. A large proportion of the respondents did not vaccinate their pigs (81%). Majority of respondents did not identify their pig herds (63%). Interestingly, majority of the respondents did not have breeding boars (73%) and sold their pigs at auctions (70%). The second objective determined semen characteristics evaluated by a Computer Aided Sperm Analyser® (CASA®) as a measure of boar fertility to be used for artificial insemination (AI). Sixteen ejaculates were collected from three Large White boars that are routinely used for semen collection purposes using the gloved-hand technique. The semen was extended with a commercial semen extender; Beltsville Thawing Solution, and the AI dose used consisted of 80mL semen sample (3×109 spermatozoa/mL). Aliquots of diluted semen were evaluated for spermatozoa motility using CASA®. Spermatozoa viability was evaluated using Synthetic Binding CD-14 (SYBR+)/Propidium Iodide (PI-), whereas spermatozoa morphology was evaluated using Eosin Nigrosin stain. The average semen volume, concentration and pH were 210 mL, 264.8 x 106 spermatozoa/mL and 7.1, respectively. The average values for total spermatozoa motility was 95.1%, ranging from 82.7 and 98.5%. However, XIX there were lower values found for progressive spermatozoa motility, ranging from 13.6 to 39.0%. The mean values for morphologically normal spermatozoa ranged from 47.8-60.9% and live spermatozoa ranged from 71.8-77.7%. The third objective determined sow fertility following AI at smallholder farms A total of 73 multiparous sows were artificially inseminated. Conception rates, farrowing rates, litter size and number born alive were recorded. The average conception and farrowing rates were 78.1 and 57.5%, respectively. Furthermore, AI resulted in acceptable fecundity (i.e., 11.8 litter size and 10.0 number of piglets born alive). The fourth objective determined the relationship between spermatozoa quality characteristics and sow fertility at smallholder farms in Gauteng Province. Of all fertility characteristics studied, conception rate was significantly related to total spermatozoa motility rate (r= 0.37, P<0.01), progressive motility (r= 0.31, P<0.01) and rapid motility (r= 0.40, P<0.01), although relatively low. There was a low negative relationship between spermatozoa morphological characteristics and fertility (P>0.05). The fifth objective determined the pre-weaning growth performance of piglets born following AI at smallholder farms of Gauteng province. Individual piglets were weighed using an electronic weighing scale. Litter size, number of piglets born alive, number of piglets weaned, the average piglet birth weight and average piglet weaned weight were recorded. The average litter size was 11.8 ± 0.2. The average birth weight and weaning weights were 1.9 and 6.2 kg, respectively. No significant differences were found between male and female piglets for all the growth performance characteristics. Piglets born during winter had a significantly higher (P<0.05) birth and weaning weight as compared to autumn and summer months. Season had a significant effect on birth and weaning weight (P<0.01). However, sex of piglets had no effect on all the characteristics recorded (P>0.05). The interaction between sex and season was only observed on the total number of weaned piglets (P<0.01). A highly significant positive correlation was found between litter size and number of piglets born alive (r= 0.86) and total number of piglets weaned (r= 0.50). A highly significant correlation was found between total number of piglets born alive and total number of piglets weaned (r= 0.55). In conclusion, the study demonstrated the potential benefit of adopting AI technology under smallholder production systems to disseminate superior genetic material to smallholder pig farmers in Gauteng Province. The total spermatozoa motility, progressive and rapid spermatozoa motility were the only spermatozoa motility characteristics significantly correlated XX with conception rate. Conversely, litter size and number born alive were not correlated with CASA® spermatozoa motility attributes. No relationships existed between spermatozoa morphological characteristics and fertility. The sex ratio percentage of piglets born following AI was 52:48% (females: males). The number of piglets born alive was 10.2 and 9.5 for number piglets weaned. Season influenced birth to weaning weight. However, sex had no significant influence at birth and weaning weight. Litter size affects the number of piglets born alive and weaned. The study showed that the introduction of advanced reproductive technologies improved productivity of pigs at smallholder pig farms in Gauteng Province.
Gauteng Department of Agriculture and Rural Development (GDARD) and Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL