Дисертації з теми "Maternal dietary crude protein"

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Foram conduzidos dois ensaios experimentais com objetivo de avaliar o efeito da redução da proteína bruta em dietas, suplementadas ou não com nitrogênio não essencial (experimento I), e de diferentes relações dietéticas de nitrogênio essencial:nitrogênio não essencial (experimento II) para poedeiras leves. Em ambos ensaios, o período experimental teve duração de 112 dias, sendo subdividido em 4 períodos de coleta de dados de 28 dias cada. No experimento I, 240 galinhas poedeiras Hy-Line W-36 aletoriamente distribuídas a 40 unidades experimentais, divididas em cinco grupos de tratamentos com 48 aves cada. Os tratamentos consistiram de 3 rações com os níveis de proteína bruta de 170.0, 150.0 e 130.0g de proteína/kg de dieta com as relações nitrogênio essencial:nitrogênio não essencial de 37/63, 42/58 e 47/53, respectivamente. Adicionalmente, as duas rações contendo os níveis de proteína bruta de 150.0 e 130.0g de proteína/kg de dieta, foram suplementadas com 37.60 e 60.80g de ácido glutâmico/kg de dieta, respectivamente, com objetivo de igualar a relação nitrogênio essencial:nitrogênio não essencial da dieta de maior nível proteico (37/63). A redução dietética da proteína bruta de 170.0g/kg para 150.0g/kg resultou na redução do peso e massa de ovos, enquanto a redução para 130.0g/kg além de acarretar piora das variáveis antes descritas, também piorou a conversão alimentar por massa de ovos, reduziu o consumo de ração e o peso de albumen. Não observou-se diferenças no desempenho e qualidade de ovos de aves alimentadas com dietas em que o conteúdo de proteína foi reduzido. A suplementação de ácido glutâmico em dietas contendo 150.0g de proteína/kg promoveu mesmo desempenho das aves alimentadas com 170.g de proteína/kg, enquanto em dietas contendo 130.0g de proteína/kg a inclusão de ácido glutâmico resultou nas piores médias de desempenho e qualidade de ovos em comparação aos demais tratamentos. Os resultados demonstram que o déficit de nitrogênio não essencial resulta em piora no desempenho de galinhas poedeiras e revela potencial de utilização de ácido glutâmico como fonte de nitrogênio não essencial, desde que utilizado em baixas concentrações. No experimento II, 360 galinhas Hy-Line W-36 foram distribuídas em seis tratamentos, com dez repetições e seis aves por unidade experimental. Os tratamentos foram obtidos a partir da suplementação gradativa da mistura de L-alanina, L-glicina e ácido glutâmico (proporção 60%/20%/20%) em uma dieta basal com reduzida proteína bruta e relação nitrogênio essencial:nitrogênio não essencial de 55/45 com objetivo de produzir as relações entre nitrogênios de 55/45, 52/48, 48/52, 44/56 e 41/59. Uma sexta dieta com maior teor de proteína bruta, denominada grupo controle, foi formulada com relação nitrogênio essencial:nitrogênio total de 41/59. As relações de 55/45 e 52/48 resultaram em menor peso de ovo e pior conversão alimentar por massa de ovos em comparação ao grupo controle. Observou-se redução nos valores de massa de ovos somente no grupo de aves alimentado com a relação de 55/45. Baseado nos resultados, recomenda-se que a relação dietética de nitrogênio essencial:nitrogênio não essencial para poedeiras leves não ultrapasse o valor de 48/52
Two trials were performed in order to evaluate laying hen responses to reduction on dietary crude protein supply and non-essential nitrogen supplementation (Experiment I) and to determine the essential to non-essential nitrogen ratio, which warrants optimum performance, and egg quality of laying hens (Experiment II). Both trials lasted 112 days, being divided in four 28-day intervals. In experiment I, a total of 240 Hy-Line W-36 laying hens were randomly assigned to 5 treatments, eight replicates with six hens each. The treatments consisted diets containing 170g (control diet), 150 and 130g crude protein/kg, which corresponded to the essential nitrogen to non-essential nitrogen ratios of 37/63, 42/58 and 47/53, respectively. The other two treatments consisted of the same diets containing 150 and 130g crude protein/kg, but supplemented with 37.60 and 79.15g glutamic acid/kg respectively in replacement to cornstarch to equal the essential nitrogen to non-essential nitrogen ratio in control diet (37/63). Reduction on dietary crude protein by 20g/kg elicited a decrease in egg weight and egg mass, whereas the reduction on dietary crude protein by 40g/kg decreased feed intake, egg weight, egg mass and albumen weight, beyond worsening feed conversion ratio per kilogram of eggs. Layers fed diets with 150 and 130g crude protein/kg had similar performance and egg quality. Glutamic acid-added diets with 150g crude protein/kg maintained similar layer performance and egg quality to that observed in layers fed control diet. However, when added to diets with 130g crude protein/kg, glutamic acid impaired layer performance and egg quality, leading to the lowest means for variables assessed herein when compared with all treatments. Based on results, the lack of non-essential nitrogen compromises layer productivity and glutamic acid may be considered as a potential source of non-essential nitrogen when added in low concentration to low-protein diets. In experiment II, 360 Hy-Line W-36 laying hens were randomly assigned to 5 treatments, eight replicates with six hens each. Experimental diets were obtained through the graded supplementation of a mixture of L- alanine, L-glycine and glutamic acid, at the proportion of 60%,20% and 20% respectively, in a low protein diet with the essential nitrogen to non-essential nitrogen ratio of 55/45. Four more diets with the ratios of 52/48, 48/52, 44/46 and 41/59 were produced from the aforementioned low-protein diet. Additionally, a diet with a higher crude protein content was formulated to contain the essential nitrogen to non-essential nitrogen ratio of 41/59. Layers given dietary essential to non-essential nitrogen ratios of 55/45 and 52/48 had lower egg weight and worsen feed conversion ratio per kilogram of eggs compared with layers fed control diet. Egg mass was impaired only when essential to non-essential nitrogen ratios reached the 55/45. Egg quality was unaffected by dietary treatments. Based on results, the dietary essential to non-essential nitrogen ratio for laying hens must not reach 48/52
O título contido no resumo em inglês não confere com a ficha catalográfica

The interaction between dietary crude protein and amino acid levels in weaner pigs in an antibiotic-free environment with or without Bacillus amyloliquefaciens supplementation Natasha van Niekerk High crude protein (CP) diets cause a myriad of digestive problems in weaner pigs due to incomplete digestion. This is caused by an immature digestive system at weaning. These problems present themselves as increased diarrhoea and reduced growth performance in weaner pigs. Many of the negative consequences could in the past be rectified through the use of antibiotic growth promoters (AGPs). However, AGPs are becoming more closely scrutinised by the general public and government officials and it is therefore imperative that alternative feed additives and dietary strategies are explored so that weaner pig performance is not impaired in the face of AGP bans. The effect of a 3% dietary CP reduction and 10% elevation of lysine, methionine, threonine, tryptophan and valine and/or Bacillus amyloliquefaciens was investigated in weaner pigs of 28 days old. The experiment was performed on 162 pigs with six dietary treatments; comprising of two CP levels (21% or 18% in the pre-starter diets and 18% or 15% in the starter diets), two amino acid levels (recommended amino acid level or elevated by 10%) and with or without the supplementation of a probiotic additive (Bacillus amyloliquefaciens). The total trial period was 42 days, divided into a pre-starter phase and starter phase, both of 21 days each. Growth performance and faecal score was measured for the entire trial period. In addition, after 21 days of the trial, 54 pigs were humanely euthanised to determine the gut health effects of the dietary treatments. Crude protein level resulted in significant effects on body weight (BW), average daily gain (ADG) and gain to feed ratio (G: F) in both the pre-starter and starter phase. The pigs consuming the HP diets had increased (p <0.05) BW at day 7, 14, 21, 28 and 35, and higher ADG (p <0.01) between days 7-14 and 7-21. In addition, high CP diets resulted in increased (p <0.05) G: F in the periods 7-14, 7-21, 21-42 and 7-42. This was due to the negative impact incurred as a result of deficiencies in certain essential AA and the standard ileal digestible (SID) Lys to CP ratio (SID Lys: CP) of 6.9% being exceeded when CP was reduced, and supplemental AA increased. The reduction in CP resulted in improved faecal scores. The supplementation of the probiotic did not result in any significant effects on performance but did exert a positive synergistic effect with the low CP diet on gut health, as observed through improved faecal score. Ileal villi height was significantly increased in high CP diets, possibly indicative of increased nutrient availability in the high CP diets. Crypt depth was also increased in the high CP diets, indicative of increased cell proliferation. There were no significant dietary effects on the pH and ammonia content of caecal digesta, or the presence and enumeration of Salmonella and Escherichia coli (E. coli) in ileal and caecal digesta. Interestingly, the supplementation of the probiotic increased the relative liver weights of the pre-starter pigs. Results of the study suggest that in order for the strategy of reducing CP in weaner pig diets to be successful, no deficiencies in essential or non-essential amino acids should be present. In addition, low CP diets in conjunction with a probiotic can improve faecal scores of weaner pigs, providing an effective solution to replacing AGPs.
Dissertation (MSc)--University of Pretoria, 2020.
Evonik Nutrition & Care GmbH
Animal and Wildlife Sciences
MSc (Agric) Animal Nutrition
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Fundação de Amparo à Pesquisa do Estado de Minas Gerais
Capítulo 1 - Foram conduzidos dois experimentos para avaliar os efeitos de tipo silagem e níveis de proteína bruta (PB) na dieta de bovinos Nelore. As dietas experimentais foram constituídas por silagem de Stylosanthes (SSt) ou silagem de milho (SM) com dois níveis de PB, 110 e 130 g PB/kg de dieta na matéria seca (MS). A relação volumoso: concentrado foi de 50:50 com base na MS. No Experimento 1, foram utilizados quatro bovinos com média de peso corporal inicial de 450 ± 37,9 kg, canulados no rúmen e abomaso. Os animais foram distribuídos em um quadrado latino 4 × 4, em esquema fatorial 2 × 2, com quatro períodos de 16 dias. Neste experimento, foram coletadas amostras de líquido ruminal, digesta abomasal, fezes, urina e sangue. Além disso, foram estimados os parâmetros cinéticos de degradação da MS, PB e fibra em detergente neutro (FDN). No Experimento 2, 40 bovinos com média de peso corporal inicial de 374 ± 16,5 kg, distribuídos em um delineamento inteiramente casualizado, em esquema fatorial 2 × 2, com dez repetições. O experimento teve duração de 99 dias, dividido em um período inicial de 15 dias de adaptação e um período de 84 dias de coleta de dados. No Experimento 2, foram avaliados o consumo, a digestibilidade dos nutrientes e o desempenho dos animais. As frações potencialmente degradáveis da MS, PB e FDN da SSt foram inferiores em relação a SM (P<0,004). As dietas contendo SSt apresentaram menor digestibilidade ruminal da matéria orgânica (MO) e menor digestibilidade total da MO, PB e FDN em comparação com as dietas contendo SM (P<0,050). As dietas contendo SSt apresentaram valores mais elevados de pH ruminal em comparação com dietas contendo SM (P=0,010). A concentração ruminal de N-NH 3 foi mais elevada para o nível de 130 g PB/kg de dieta, em comparação com 110 g PB/ kg de dieta (P<0,001). Os níveis de PB das dietas afetaram o nitrogênio ureico no sangue (P<0,001) e na urina (P=0,017), e em ambas as dietas contendo SSt e SM foram superiores para o nível de 130 g de PB/kg de dieta. As dietas contendo SSt apresentaram maior consumo de MS, MO, PB, FDN e fibra em detergente neutro indigestível (FDNi) em comparação dietas contendo SM (P<0,008). No entanto, a quantidade de nutrientes digeridos (kg/dia) foi semelhante entre os tratamentos (P>0,050). O tipo de silagem e nível de PB na dieta não apresentaram efeito sobre o desempenho produtivo (P>0,050), porém as dietas contendo SSt tenderam a diminuir a eficiência alimentar (P=0,085). Contudo, a SSt e o nível de 110 g PB/kg de dieta podem ser utilizados para alimentação na terminação de bovinos confinados. Capítulo 2 - Foram isoladas cento e cinquenta e uma cepas de bactérias do acido lático (BAL) da silagem de planta inteira de milho. As identificações foram baseadas na análise da sequência de rDNA 16S. As espécies predominantes foram Lactobacillus plantarum 53,0%, Pediococcus pentosaceus 11,9%, Lactobacillus buchneri 9,9%, Lactobacillus pentosus 5,3%, Weissella cibaria 4,6%, e Lactobacillus brevis 4,0%. As estirpes de Lactobacillus buchneri foram predominantes no dia 56 de ensilagem. Oito estirpes de L. buchneri foram pré-selecionadas de um total de 15 estirpes com base na taxa de crescimento e na produção de metabólitos. As estirpes selecionadas foram avaliadas na fermentação e estabilidade aeróbia de silagens de milho e cana-de-açúcar. Não houve melhoria no teor de MS, população de mofo e leveduras, perdas de MS e estabilidade aeróbia da silagem de milho (P>0,050) inoculadas com as estirpes 56.22, 56.27, 56.28, e 56.29. Enquanto as estirpes 56.1, 56.4 e a comercial 40788, quando inoculadas em silagem de cana-de-açúcar, apresentaram os maiores teores de MS e menores de perda de MS em comparação com a silagem contole (P<0,050). A estirpe comercial apresentou a menor população de mofos e leveduras após 90 dias de ensilagem (P = 0,024). No entanto, a estabilidade aeróbia não foi afetada. Após a exposição ao ar, todas as silagens deterioram e apresentaram elevada população de mofos e leveduras. A pré- seleção de estirpes de L. buchneri com base na produção de ácido acético apresentou os melhores resultados no processo de ensilagem. Assim, as estirpes 56.1 e 56.4 são promissoras para utilização como inoculante para silagem de cana-de-açúcar.
Chapter 1 - Two trials were conducted to evaluate the effects of silage crop and levels of dietary crude protein (CP) in Nellore beef cattle. The experimental diets consisted of Stylosanthes (StS) or corn silage (CS) with two levels of dietary CP, 110 and 130 g CP/kg diet on dry matter (DM) basis. The forage to concentrate ratio was 50:50 on a DM basis. In Experiment 1, four bulls were used, with an average initial body weight (BW) of 450 ± 37.9 kg, surgically cannulated in the rumen and abomasum. The bulls were assigned to a 4 × 4 Latin square with a 2 × 2 factorial design of treatments, and four 16-day periods. In this experiment, we collected ruminal fluid, abomasal digesta, feces, urine, and blood. In addition, the kinetic parameters of DM, CP and neutral detergent fiber (NDF) degradation were estimated. In Experiment 2, 40 bulls with an average initial BW of 374 ± 16.5 kg were distributed into a 2 × 2 factorial in a randomized design with ten replicates. The trial lasted 99 days and was divided into a 15-day period for adaptation and an 84-day period for data collection. The intake and digestibility of nutrients, as well as animal performance were evaluated in Experiment 2. The potentially degradable fractions of DM, CP, and NDF of StS were lower than CS (P<0.004). The diets containing StS showed lower ruminal digestibility of organic matter (OM) and lower total digestibility of OM, CP, and NDF than diets containing CS (P<0.050). The StS-based diets showed higher values for ruminal pH in comparison with CS-based diets (P=0.010). The ruminal NH 3 -N concentration was higher for the level of 130 g CP/kg diet in comparison with 110 g CP/kg diet (P<0.001). The dietary CP level affected urea nitrogen in blood (P<0.001) and urine (P=0.017), which in the diets containing StS and CS were higher at the level of 130 g CP/kg diet. The diets containing StS showed higher intake of DM, OM, CP, NDF, and indigestible neutral detergent fiber (iNDF) than diets containing CS (P<0.008). However, the amount of digested nutrients (kg/d) was similar between treatments (P>0.050). The silage crop and dietary CP levels had no effect on productive performance (P>0.050), but the StS-based diet tended to decrease feed efficiency (P=0.085). Thus, StS, as well as the level of 110 g CP/kg diet, can be used to feed finishing beef cattle. Chapter 2 - One hundred and fifty-one LAB strains were isolated from whole-plant corn silage in tropical weather. Their identifications were based on sequence analysis of 16S rDNA. The predominant species were Lactobacillus plantarum 53.0%, Pediococcus pentosaceus 11.9%, Lactobacillus buchneri 9.9%, Lactobacillus pentosus 5.3%, Weissella cibaria 4.6%, and Lactobacillus brevis 4.0%. Lactobacillus buchneri strains were predominant at day 56 of ensiling. Eight L. buchneri strains from a total of 15 were preselected, based on growth rate and metabolites production. The strains selected were evaluated on fermentation and aerobic stability of corn and sugarcane silages, four strains in each crop. There was no improvement of the inoculation with the strains 56.22, 56.27, 56.28, and 56.29 on the DM content, yeast and molds population, DM losses, and aerobic stability of corn silage (P > 0.050). Inoculated silages had lower concentration of acetic acid and higher ethanol in comparison with the control silage (P < 0.050). While the strains 56.1, 56.4, and 40788 showed highest DM content, and lowest DM losses when applied in sugarcane silage. At day 90 of ensiling, the commercial strain showed lowest population of yeasts and molds in sugarcane silage. However, the aerobic stability was not affected. After air exposure, all silages deteriorate and had high population of yeast and molds. Preselection of L. buchneri strains based on acetic acid production showed the best results on silage fermentation. Thus, the strains 56.1 and 56.4 are promising for use as an inoculant in sugarcane silages.

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Este trabalho foi desenvolvido baseado em 2 experimentos conduzidos no confinamento experimental do laboratório animal do Departamento de Zootecnia da Universidade Federal de Viçosa, e os resultados são mostrados em dois capítulos. O objetivo do primeiro experimento foi utilizar o 15 N para estimar a contaminação microbiana (CM) das seguintes frações da proteína bruta (PB): fração solúvel (a), insolúvel potencialmente degradável (b) e a taxa de digestão da fração b (kd). Assim como determinar os tempos de incubação necessários para estimar a proteína degradável no rúmen (PDR) de concentrados energéticos e proteicos, considerando duas taxas de passagem (0,05 h -1 e 0,08 h -1 ). Doze alimentos foram avaliados, sendo seis concentrados energéticos (farelo de trigo, farelo de arroz, fubá de milho, sorgo moído, milho desintegrado com palha e sabugo e casca de soja) e seis concentrados proteicos (farelo de algodão 38% PB, farelo de soja, feijão moído, farelo de amendoim, farelo de girassol e farelo de glúten de milho). Os alimentos foram divididos e quatro grupos e incubados no rúmen de quatro touros fistulados. Os alimentos foram incubados por 0, 2, 4, 8, 16, 24, 48 e 72 horas. Para determinar a CM dos resíduos incubados, as bactérias ruminais foram marcadas com 15 N através de infusões ruminais contínuas de 15 (NH 4 ) 2 SO 4 . Digesta ruminal foi coletada para isolamento de bactéria antes da primeira infusão de 15 N, durante o período de adaptação, e após a infusão de 15 N nos períodos de coleta. Não foi observada diferença (P > 0,05) nos parâmetros a, b e kd corrigidos e sem correção para todos os alimentos avaliados. Todos os alimentos seguiram um modelo exponencial de degradação, exceto o glúten de milho. Provavelmente porque o tempo máximo de incubação utilizado (72 horas) não foi longo o suficiente para permitir uma estimativa acurada do perfil de degradação. A análise cluster (R2 = 0.944) permitiu agrupar os alimentos em três diferentes grupos de acordo com o tempo necessário parra estimar a PDR. O primeiro grupo foi formado por concentrados energéticos com alto teor de amido (15.4 ± 0.46 h), o segundo por concentrados energéticos com baixo teor de amido (6.8 ± 0.60 h) e o terceiro por concentrados proteicos (9.9 ± 0.41), considerando taxa de passagem de 0,05 h -1 . Como conclusão, a contaminação microbiana foi baixa e não significativa, assim a correção da degradação proteica torna-se irrelevante para os concentrados utilizados neste estudo. No entanto a composição química dos alimentos resultou em diferentes tempos de incubação para estimar o conteúdo de PDR, e isto precisa ser levado em consideração nas técnicas utilizadas para estimar a digestibilidade ruminal e intestinal da PB. O objetivo do segundo experimento foi avaliar se a redução nos níveis de proteína bruta (PB) da dieta afeta o desempenho animal, exigências de energia e proteína, perdas nitrogenadas e emissão de metano entérico em machos Nelore não castrados na fase de terminação. Vinte e seis animais com idade média de 20 ± 1 mês e peso corporal inicial de 296 ± 8,1 kg foram utilizados neste experimento. Quatro animais foram designados ao grupo referência, sendo abatidos ao início do experimento. Quatro animais foram alimentados a nível de mantença, enquanto dezoito animais foram divididos em três grupos (n = 6 em cada grupo), e foram aleatoriamente designados a tratamentos consistindo de três níveis de PB na dieta: 10, 12 e 14% de PB. Ao final do experimento todos os animais foram abatidos para determinação de sua composição química corporal, exigências de energia e proteína e características de carcaça. Foi observado efeito linear do nível de PB da dieta sobre o consumo e digestibilidade da PB, onde os maiores valores foram obtidos para animais alimentados com 14%PB. O metabolismo do nitrogênio foi afetado pelos níveis de PB, onde animais alimentados com 12 e 14 % PB tiveram maior excreção urinaria de N que aqueles alimentados com 10% PB. Não houve efeito do nível de PB dietético sobre retenção de N, desempenho animal e características de carcaça, e também não foi observado efeito do nível de PB da dieta sobre a eficiência microbiana e emissão de CH 4 . Este estudo mostrou que para bovinos em terminação o nível de PB da dieta não influencia a deposição muscular e a emissão de gases do efeito estufa. A redução do nível de PB das dietas não afetou o consumo de MS, desempenho e características de carcaça, sugerindo que o uso de 10% PB em dietas de terminação reduz o impacto ambiental devido a menor excreção urinária de N que dietas de 12 e 14% PB. Animais alimentados com 10, 12 e 14% de PB nas dietas tiveram emissões de 3.893, 3.755 e 4.255 g/d de equivalente CO 2 respectivamente e não foram observadas diferenças entre as dietas. Além disso a emissão de metano não foi afetada por níveis de PB da dieta variando entre 10 e 14%, sendo em média igual a 16,3 g/kg do consumo de MS. Este estudo mostrou que a redução do nível de PB da dieta não influenciou o desempenho animal e reduziu as perdas nitrogenadas nas fezes e urina sem afetar a emissão de metano. Porém é importante destacar que mais estudos são necessários para confirmar esses resultados.
This study was developed based on two experiments conducted on the feedlot and Animal Laboratory of Animal Science Department of Universidade Federal de Viçosa, and the results are shown in two chapters. The aim of the first study was to use 15 N to estimate the microbial contamination (MC) of crude protein (CP) fractions that were soluble (a) as well as insoluble but potentially degradable (b), and the digestion rate of fraction b (kd), as well as to determine the incubation time necessary to estimate the rumen degradable protein (RDP) of energy and protein feeds when considering two outflow rates (0.05 h -1 and 0.08 h -1 ). Twelve types of feeds were evaluated, with six energy concentrates: wheat bran, rice meal, ground corn, ground sorghum, ground corn cob, and soybean hulls; and six protein concentrates: cottonseed meal 38% CP, soybean meal, ground bean, peanut meal, sunflower meal, and corn gluten meal. The feeds were divided into 4 groups and were incubated in the rumens of 4 crossbred bulls. The feed samples were incubated for 0, 2, 4, 8, 16, 24, 48, and 72 h. To determine the MC of the incubated residues, ruminal bacteria were labeled with 15 N via continuous intraruminal infusion of 15 (NH 4 ) 2 SO 4 . Ruminal digesta were collected for the isolation of bacteria before the first infusion of 15 N during the acclimation period, and after the infusion of 15 N during the collection period. There was no difference (P > 0.05) in the parameters a, b, and kd, corrected and uncorrected, for all feeds that were evaluated. All of the feed tests followed an exponential model of degradation and the model fitted well to the data, except for corn gluten meal, probably because the maximum incubation time that was used (72 h) was not long enough to allow for an accurate estimation of the degradation profile. The cluster analysis (R2 = 0.944) allowed for the grouping of feeds into three different groups according to the necessary incubation time to estimate RDP. The first was formed by the high-starch energy concentrates (15.4 ± 0.46 h), the second by the low-starch energy concentrates (6.8 ± 0.60 h), and the third by the protein concentrates (9.9 ± 0.41) while considering a kp of 0.05h -1 . In conclusion, the microbial contamination was low and non-significant; therefore, correction of ruminal protein degradation is irrelevant with regards to the concentrate that was studied. However, the chemical composition of this feeds resulted in different incubation times to estimate RDP content, and this has to be taken into account in the techniques that are used to determine CP digestibility in the rumen and intestines. The aim of the second experiment was to evaluate whether a reduction in dietary crude protein (CP) content affects animal performance, energy and protein requirements, N losses, and enteric methane emission in finishing Nellore bulls. Twenty-six animals, with an average age of 20 ± 1.0 months and initial body weight (BW) of 296 ± 8.1 kg were used in this experiment. Four animals were used as baseline reference animals and were slaughtered at the beginning of the experiment. Four animals were fed at maintenance level (MAIN), whereas 18 bulls were divided into 3 groups (n = 6 in each group) and were randomly assigned to the treatments consisting of three levels of CP in the diets: 10, 12, and 14% of CP. At the end of the experiment, all animals were slaughtered to evaluate their chemical body composition, energy and protein requirements, and carcass characteristics. A linear effect was observed for dietary CP level on CP intake and digestibility, while greater values were obtained for animals that were fed 14% CP. Nitrogen metabolism was affected by CP levels, where animals that were fed 12 and 14% CP had greater urinary N losses than those that were fed 10% CP. There was no effect of CP level on retained N, animal performance, and carcass characteristics among diets, and there was no effect of CP level on microbial efficiency and CH 4 emissions. Thus, this study showed that for finishing bulls, the level of dietary CP did not interfere with muscle deposition and greenhouse gas emissions. The reduction of CP content in diets does not affect DM intake, animal performance, and carcass characteristics, thereby suggesting that the use of 10% of CP in diets for finishing bulls reduces their environmental impact due to a lower urinary N excretion than 12 and 14% CP-based diets. Animals that were fed 10, 12, and 14% CP diets had emissions equivalent to 3,893; 3,755; and 4,255 g d -1 of CO 2 , respectively, and no difference was observed among diets. Furthermore, methane emission is not affected by CP levels ranging between 10 to 14% which, on average, is 16.3 g kg -1 of DM intake. Our study found that a decreased CP level did not influence animal performance, but it did decrease N losses in manure without affecting methane emissions. However, it is important to highlight that more studies are necessary to confirm these results.

Master of Science
Department of Animal Sciences and Industry
Joe D. Hancock
Six experiments were completed to determine factors influencing the use of distillers dried grains with solubles (DDGS) in diets for nursery and finishing pigs. In Exp. 1, 105 nursery pigs were fed corn-soybean meal (SBM) based diets with CP concentrations of 22.5, 25, and 27.5%. Overall ADG, ADFI, and G:F were not affected by increasing CP (P > 0.19). In Exp. 2, 105 nursery pigs were fed excess CP from SBM and DDGS. Overall ADG, ADFI, and G:F for pigs fed the control diet were not different from those fed the high CP treatments (P > 0.12). However, pigs fed the DDGS treatment had lower G:F than pigs fed the corn-soy diet with similar CP content (P < 0.04). For Exp. 3, 176 finishing pigs were fed diets with CP concentrations increasing from 12 to 18%. Increasing CP had no effect (P > 0.20) on ADG, ADFI, G:F, and hot carcass weight (HCW). For Exp. 4, 180 finishing pigs were fed excess dietary CP from SBM and DDGS. Pigs fed diets with high CP had lower ADG, ADFI, and HCW, but these results were caused by the diet with 40% DDGS (SBM vs DDGS, P < 0.001). For Exp. 5, 224 nursery pigs were used to determine the effects of extrusion processing on the nutritional value of DDGS. Overall ADG and ADFI were greater for pigs fed the corn-soy control compared to the DDGS treatments (P < 0.02). Extruding the DDGS did not improve ADG or G:F (P > 0.11), but DM and GE digestibility were greater for diets with extruded DDGS vs. unprocessed DDGS (P < 0.04). In Exp. 6, 200 finishing pigs were fed DDGS-based diets formulated for ME, NE, and digestible amino acids. Feeding DDGS lowered ADG (P < 0.09) and ADFI (P < 0.05). Formulating for ME, NE, and digestible amino acids needs improved ADG and G:F (P < 0.002) to that of the corn-soy control diet. In conclusion, moderate excesses of dietary CP does not impact growth performance. Also, extruding DDGS can improve the nutritional value of diets for nursery pig and formulating for ME, NE and digestible amino acid needs can improve growth performance of finishing pigs fed diets with high levels of DDGS.

Numerous studies, including those in agriculturally important species, have shown that maternal nutritional status during gestation influences the fetal development, postnatal growth pathways and metabolism and reproductive development of the offspring. Wide variation in pasture quality and quantity available for the cow herd throughout the breeding season and during gestation is common in extensive grass-fed beef production systems. In the northern Australian rangelands, protein, rather than energy, is the major limiting nutrient for cattle in dry-season pastures with protein supplementation of breeding heifers an animal husbandry requirement. Few studies in cattle have specifically evaluated the effects of maternal protein restriction and/or supplementation on the fetal and postnatal development of the offspring. This thesis investigates the effect of low and high protein intake in nulliparous beef heifers during the peri-conception and first trimester of gestation upon feto-placental growth and the subsequent postnatal growth and reproductive development of the male offspring. Furthermore, the impact of maternal nutrition on appetite, feedlot performance and carcass traits was evaluated in the male offspring. The outcomes of the first three chapters of this thesis highlight the importance of the peri-conception period and first trimester upon fetal and placental development. We have demonstrated that protein restriction (125 % versus 70 % of requirement) during the peri-conception period and first trimester decreased early fetal growth in the bovine in a sex-specific manner in association with maternal endocrine perturbations, and may contribute to early embryonic loss. Furthermore, we show that protein restriction during the peri-conception period and first trimester alters placenta parameters and produces asynchronous organ development in the bovine by 98 days post-conception. After feeding to meet nutritional requirements (but not realimentation) during the second and third trimester, the observed differences in fetal and gross placenta parameters measured at 98 days post-conception were not present at birth. Intriguingly, the sex-related differences apparent at 98 days post-conception and normally observed in birth weight in the neonate were disrupted. This suggests sex- specific catch-up growth to term dependent upon early gestational dietary treatment. We propose that placental adaptations and an accelerated growth response in the restricted female fetus reduced the observed differences in fetal weight apparent at 98 days post-conception after the nutritional treatment ceased, thereby disrupting the normal disparity in birth weight between heifer and bull calves. However, as indicated by the differing fetal organ measures at the end of the first trimester, similarity in birth weight does not preclude that developmental programming of the structure and/or function of the fetal organs and tissues has already occurred following nutritional stress in early gestation. On the contrary, prior studies have shown that birth weight is not a satisfactory indicator of intrauterine growth restriction and that suboptimal maternal nutrition may have lasting effects on the post-natal growth and development and health of the offspring. The second component of this study, which forms the final two chapters of the thesis, examined the post-natal growth and reproductive development of the non-castrated male offspring through to slaughter at 598 days of age. We demonstrated in the developing bull, that low dietary protein during the peri-conception period lowered sperm quality parameters during pubertal development with a concomitant delay in age of puberty. These effects were subsequent to lower FSH concentrations in this low peri-conception group. The circulating hormone data suggest that the peri-conception diet may have altered the development of the hypothalamic–pituitary-gonadal axis and the corresponding receptivity to circulating hormones. These male offspring underwent a 70-day residual feed intake feedlot test commencing at 528 days of age. Offspring from heifers that had a change in diet at the end of the peri-conception period from high protein to low protein, and visa versa, had 9% daily higher feed intake on test than offspring of mothers that remained on a constant low protein diet throughout the peri- and post-conception period. Offspring liveweight, feed efficiency and carcass weight were not different among bulls, however dressing percentage, estimated retail beef yield and eye muscle (longissimus dorsi) area were all lower in offspring of heifers fed a low protein diet during the first trimester. Significantly, these findings on the sex-specific effects of peri-conceptional dietary perturbations in cattle represent the first such data in a mammalian species with ovary structure, embryonic development and gestational length similar to the human. In combination, this work represents the first study to highlight the importance of maternal dietary protein intake during the peri-conception period and first trimester upon fetal and postnatal development in beef cattle. In a pasture-based production system where variation in feed quality through breeding and gestation occurs, quantification of these effects upon long term productivity of the progeny and elucidation of the causal mechanisms remains an important area of study.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, Adelaide Medical School, 2018

Fertility of Broiler Breeders (BBs) has been researched over many years with inconclusive findings. Genetic selection and improvements in growth traits have had negative effects on fertility of BB. One explanation is related to overweight birds, resulting in the inability of birds to copulate successfully, with no cloacal contact. The requirements of CP for egg production in BB females have been quantified, but there is less literature on how CP affects fertility in male BBs. The objective of this experiment was to investigate the effects of feeding BB males different dietary CP intakes (10.4, 12.4, 14.2, 17.8, 19.3 and 20.1 g CP/bird/day) on fertility in flocks with natural mating and in birds that were artificially inseminated (AI). Results showed that birds consuming 10.4 and 12.4 g CP/bird/day resulted in weight loss (between 24.9 and 23.6% and 26.5 and 22.4% below target BW) over the 29 weeks of the experimental period in both natural mating and individual pens respectively. Intakes of higher protein content (17.8- 20.1 g CP/bird/day) however resulted in BW gain over the experimental period. Hatch percentage across all CP intakes throughout the duration of the study was found to be high, ranging between 75- 100 and 80-95 % in AI and naturally mated birds respectively, and not affected by CP intakes. Similar results for predicted fertility using the methods published by Brillard & Antoine (1990) and Wishart (1997) were found; however Brillard & Antoine (1990) is more lenient requiring less outer perivitelline layer (OPVL) sperm/mm2 to pronounce an egg fertile. Improved fertility predictions could have been made by using examination of inner perivitelline layer (IVPL). There was a tendency for a superior response in predicted fertility from birds with a protein intake of 14.2 g CP/bird/day. This intake also least affected the BW of the male birds and thus 14.2 g CP/bird/day can be recommended for optimal BB male performance.
Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

碩士
國立屏東科技大學
畜產系
91
The objective of this study was to investigate the requirement of dietary crude protein and metabolizable energy in green eggshell laying hens(Hokinaica ♂×Hyline ♀), bred by Department of Animal Science, National Ping-Tung University of Science and Technology. This study included four experiments. Experiment 1: The requirement of dietary crude protein at summer and winter in 26 to 32 weeks old green eggshell laying hens. Ninety six 26 weeks old green eggshell laying hens were randomly divided into four treatment groups with 24 replicates. Experiment diets were formulated to contain ME 2800 kcal/kg, Ca 3.8% and AP 0.45 %, and four protein intake levels were 17, 18, 19 and 20 g. The experimental period was six weeks. Experiment 2: The requirement of dietary crude protein at summer and winter in 52 to 58 weeks old green eggshell laying hens. Ninety six 52 weeks old green eggshell laying hens were randomly divided into four treatment groups with 24 replicates. Experiment diets were formulated to contain ME 2760 kcal/kg, Ca 3.6% and AP 0.35 %, and four protein intake levels were 15.5, 16.5, 17.5 and 18.5 g. The experimental period was six weeks. Experiment 3: The requirement of dietary metabolizable energy at summer and winter in 34 to 40 weeks old green eggshell laying hens. Ninety six 34 weeks old green eggshell laying hens were randomly divided into four treatment groups with 24 replicates. Experiment diets were formulated to contain CP 19%, Ca 3.6% and AP 0.35 %, and four metabolizable energy intake levels were 272, 280, 288 and 296 kcal. The experimental period was six weeks. Experiment 4: The requirement of dietary metabolizable energy at summer and winter in 60 to 66 weeks old green eggshell laying hens. Ninety six 60 weeks old green eggshell laying hens were randomly divided into four treatment groups with 24 replicates. Experiment diets were formulated to contain CP 17.5%, Ca 3.6% and AP 0.35 %. Diets containing four metabolizable energy intake levels were 270, 276, 282 and 288 kcal. The experimental period was six weeks. Every treatment took 4 eggs to measure the eggshell quality, component parts of egg and egg quality in every week. At 0, 3 and 6 weeks of experiment, body weight were recorded, fecal sample were collected and blood sample were taken from the brachial vein of wing from 6 birds of each treatment, for measurement of plasma uric and total protein and fecal nitrogen. Results showed the diet containing 2800 kcal/kg metabolizable energy were intake crude protein 19g/day and the diet containing 2760 kcal/kg metabolizable energy were intake crude protein 18.5g/day was sufficient to maintain better laying performance, component parts of egg and egg quality of green eggshell laying hen through 26 to 32 and 52 to 58 weeks of age. The diet containing 19% crude protein were intake M.E. 296 kcal/day and the diet 17.5% crude protein were intake ME 288 kcal/day was sufficient to maintain better laying performance, component parts of egg and egg quality of green eggshell laying hens through 34 to 40 and 60 to 66 weeks of age.

Methane emissions of 60 steers (321 ± 14 kg) fed isocaloric forage diets differing in crude protein (CP) content were measured at ambient daily temperatures averaging -17.5°C to determine if increased nitrogen status, measured by blood urea nitrogen (BUN), decrease CH4 as a percent of gross energy intake (% GEI) from backgrounding cattle. Average BUN concentrations (mmol L-1) were 0.81, 1.82, 3.05 and 3.51 (SE ± 0.108) for diets with 6.9% (low), 10.3% (adequate for rumen microbes), 11.1% (adequate for muscle growth) and 13.6% (excessive) CP respectively. Methane (% GEI) emissions decreased with increasing CP over time (P=0.04). Increasing CP content increased BUN levels and decreased methane emissions (% GEI). Although models were developed to predict CH4 emissions (% GEI) from steers and cows using a backward-elimination process, BUN accounted for only 0.7 to 5.7% of the partial R2 and therefore has limited value when modelling methane emission predictions.
February 2016

This study was conducted to investigate the effects of varying levels of dietary lysine and feed allocation, on the performance of female broiler breeders. In trial 1, 900 Cobb breeders from 26 to 45 weeks of age were used. The first four treatments had a fixed level of lysine throughout the experimental period, with 1200, 1070, 930 and 800 mg Lysine/bird/day and the last two treatments had their levels of lysine changed every two weeks, with treatment five started off with 1200 mg lysine/bird/day followed by a gradual decrease up to 975 mg lysine/bird/day at 45 week old, while treatment six started with the lowest level of lysine, 800 mg/bird/day and at 45 week old the intake was 1025 mg/bird/day. The rations provided 1900KJ ME/ day, the birds received 160 g of feed/day. Dietary lysine did not affect body weight, egg production, or egg composition. There were no significant differences in age at 50%, or peak production. Birds receiving 1070 and 1025 mg lysine/bird.day had a slightly, but not significantly, higher production in the current study. Birds receiving 1200 mg lysine/bird.day had the highest body weight and the lowest egg production. In trial 2, 900 broiler breeder hens were used. Protein intake and feed allocation were changed for each treatment at 26, 38 and 50 weeks and ending at 60 weeks. Birds on T1 were fed a constant CP content (145 g protein/kg) but a decreasing feed allocation (175 to 145 g/d). Those on T2 had a constant feed allocation (160 g/d) and a decreasing CP (166 to 124 g/kg) while those on T3 had varying levels of protein (166, 124 and 166 g/kg) and feed allocation (160, 160, 145 g/d). Mean cumulative protein intakes were 5.2, 5.3 and 4.8 kg/bird and mean energy intakes were 417, 412 and 402 MJ/bird for T1, T2 and T3 respectively. Body weights differed significantly at the end of the trial (P<0.05) with T2 showing the highest weight gain. However, egg production, egg weight and egg output were not affected by treatment. These breeders did not benefit from the additional protein and energy provided in the first and second periods by T1 and T2 (vs. T3), nor did they benefit from the additional energy provided in the final ten weeks of production by T2.
M.Sc.Agric. University of KwaZulu-Natal, Pietermaritzburg 2013.

碩士
國立屏東科技大學
畜產系
91
Abstract The objectives of this study were to investigate the effect of dietary protein levels on growth performance and carcass characteristics in black silkies. The chickens were the black silkies. A completely randomized design（CRD）used in this experiment. 240 black silkies were randomly divided to four treatment groups with three repeats. There were 12 pens chickens, including half of the male and female. Water and feed were supplied ad libitum. Corn-soybean meal was used as a basal diet. This experiment were divided to three stage（0 to 6, 7 to 12 and 13 to 20 weeks）, according to their different growth period. The dietary crude protein（CP, %）levels were 23.0, 21.5, 20.0 and 18.5% respectively, the metabolizable energy（ME, kcal / kg） content were 3100 and the calcium（Ca）and available phosphate（AP.）were 1.1 and 0.5% of the 0 to 6 weeks. In 7 to 12 weeks, the dietary protein levels were 21.5, 20.0, 18.5 and 17.0% respectively, ME were 3000（kcal / kg）and Ca and AP. were 0.9 and 0.45%. In 13 to 20 weeks, the dietary protein levels were 20.0, 18.5, 17.0 and 15.5% respectively, ME were 3050（kcal / kg）and Ca and AP. were 0.85 and 0.4%. Different protein levels of different growth stage were to investigate the protein demand of black silkies. Each treatment took randomly 12 chickens（half of the male and female）that slaughtered and analyzed their carcass characteristics, general composition, collagen content, shear value, selenium content and phosphoserine content of meat in 16, 18 and 20th week. The results of this experiment showed that different dietary protein levels had no effect on live-weight gain, feed intake（FI）and feed conversion ratio（FCR；p＞0.05）. But increased the dietary protein levels could significantly decreased the protein efficiency ratio（PER）（p＜0.05）, the 18.5% dietary protein content of treatment group had the best result. The results of 7 to 12 weeks were like 0 to 6 weeks. The different dietary protein levels（21.5, 20.0, 18.5 and 17.0%）had no significantly effect on live-weight gain and FCR（p＞0.05）. FI and protein intake（PI）decreased significantly （p＜0.05）while dietary protein levels decreased. PER decreased significantly（p＜0.05） while dietary protein levels increased. The dietary protein level 17.0% had the best PER. In 13 to 20 weeks, different dietary protein levels（20.0, 18.5, 17.0 and 15.5%）on live-weight gain, FI and PER of black silkies had no significantly different（p＞0.05）. PI increased significantly（p＜0.05） while dietary protein level increased. FCR of dietary protein level 15.5% of treatment group had significantly higher（p＜0.05） than three other treatment groups（20.0, 18.5 and 17.0%）. The results of carcass characteristics test showed that dietary protein levels had no effect on dressing percentage of 16th week, there were not significantly different （p＞0.05）among treatment groups. There were significantly different（p＜0.05） on breast percentage but they were no concern of dietary protein levels. In sexes, the breast percentage of female had significantly higher（p＜0.05） than male. Other items, like dressing percentage, thigh percentage and abdominal fat percentage had no significantly different（p＞0.05） between sexes. The dietary protein levels had no effect the results of dressing percentage, breast percentage, thigh perentage and abdominal fat percentage of 18th week. In sexes, dressing percentage of male had significantly higher（p＜0.05） than male in dietary protein levels 18.5 and 15.0%. There were not significantly different （p＞0.05）between other treatment groups about sexes. In dietary protein level 20.0% of treatment group the breast percentage of female had significantly higher（p＜0.05） than male, but there were not significantly different（p＞0.05） between other treatment groups. The male of thigh percentage of treatment group 18.5% had significantly higher（p＜0.05）than female, but there were not significantly different （p＞0.05）between other treatment groups. Abdominal fat percentage was not concern of sexes. In 20th weeks, there were not significantly different（p＞0.05） among dressing percentage, breast percentage and thigh percentage and they were not concern of dietary protein levels. About abdominal fat percentage, the lower dietary protein level group had more abdominal fat percentage（p＜0.05）. In sexes, dressing percentage of male had significantly higher（p＜0.05） than female, but breast percentage, thigh percentage and abdominal fat percentage had no significantly different（p＞0.05）. The results of general composition analysis showed that the moisture, ash and crude fat content of breast and thigh meat in 16th, 18th or 20th week had no effected by dietary protein levels（p＞0.05）. But dietary protein levels had significantly effect on crude protein content of breast and thigh meat. The hugher dietary protein level group had more crude protein content of meat（p＜0.05）. About sexes, crude protein, crude fat, moisture and ash content of meat had no significantly different（p＞0.05） in any weeks and parts. The results of shear value showed that the shear value of breast and thigh meat in 16, 18 or 20th week had no effected （p＞0.05）by dietary protein levels. There were not significantly effected by dietary protein levels about sexes. About ages, muscle of 18th weeks in black silkies had the best shear value. Results in collagen content analysis indicated that total collagen（TC） content and thermal residual collagen（TRC）content of breast and thigh meat in 16, 18 or 20th week had effected by dietary protein levels. The higher protein level group had higher TC and TRC content（p＜0.05）. In sexes, there were not significantly effect （p＞0.05）on breast or thigh meat. The meat of black silkies selenium content was 1.35±0.13 ppm and phosphoserine content by mixed breast and thigh meat was 27.63±5.23 mg / 100g. It was good for human on health and strength. Summarized this study, the best dietary protein levels of black silkies in 0 to 6 weeks was 18.5％, 7 to 12 and 13 to 20 weeks were 17.0％. In carcass characteristics, the 18th week of black silkies were more suitable for slaughtered.

碩士
國立屏東科技大學
畜產系
93
The purpose of this study was to investigate the effects of dietary crude protein and metabolizable energy levels on growth performance and carcass characteristics in Black bantams. A total of 288 male Black bantams at 0 week of age were randomly divided to nine treatment groups with two repeats. There were 16 birds in each group. A 3×3 factorial design was used which included combinations of three CP levels and ME levels. The experiment included three growth stages (0 to 6, 7 to 12, and 13 to 20 weeks of age, respectively). All diets were corn and soybean based meal. During 0 and 6 of age, the dietary levels of crude protein were 19, 21 and 23%, respectively, and the corresponding levels for metabolizable energy were 3000, 3100 and 3200 kcal/kg. In 7 to 12 and 13 to 20 weeks, the dietary included the crude protein levels were 17, 19 and 21 % respectively, metablolizable energy levels were 2950, 3050 and 3150 kcal/kg. Water and feed were fed ad libitum. The feed intake was recorded daily and body weight measured every two weeks. Four chickens were randomly chosen for carcass evaluation and general composition and collagen content analysis at 14, 16, 18 and 20 weeks of age for each group. The results indicated that birds fed 19% CP level and 3200 kcal/kg ME level had the best growth performance in 0-6 weeks of age (P < 0.05). However, 17% CP and 2950 kcal/kg ME group birds had the best growth performance in 7-12 and 13-20 weeks of age (P < 0.05). Although no significant CP effects on feed intake was observed, the effects of ME on feed intake was significant. Carcass results showed no significant effect of crude protein and metablolizable energy levels on live weight, dressing percentage, breast percentage and thigh percentage at 14, 16, 18 and 20 weeks of ages (P > 0.05). The results of general composition analysis showed that moisture and crude fat content of breast and thigh were significantly affected by the level of CP (P < 0.05). The dietary metablolizable energy levels had significant effect on crude fat content of breast and thigh at ages evaluated (P < 0.05). Both total collagen ( TC ) and thermal residual collagen ( TRC ) contents of breast and thigh meat at 14, 16, 18 and 20 weeks of age were significantly affected by crude protein level ( P < 0.05 ). The thermal residual collagen ( TRC ) content was increased as age increased ( P < 0.05 ).

Since no effect on CP and diet type on the optimal Trp-to-Lys ratio (TLR) was found in two previous experiments, two extra experiments were planned. In the first one, piglets were fed a Lys-deficient basal diet supplemented with crystalline Lys (to create graded levels of SID Lys). GFR and PUN were measured every 5-d for 15-d; and were analyzed using the broken-line analysis to determine the Lys requirement. As SID Lys level increased, GFR increased linearly and PUN decreased linearly. The SID Lys requirement for was estimated to be 1.02%. To determine the optimal TLR, pigs were fed Trp-deficient basal diet supplemented with crystalline Trp (to create graded levels of SID TLR). Most of the parameters evaluated failed (P > 0.10) to yield an estimate. Based on the evidence we suggest that the optimal SID TLR for early-weaned pigs fed a wheat-barley diet lies below 17.75%.

There are negative influences of selection for broiler growth on the reproductive ability of broiler breeder parents. This is mostly due to problems related to excessive body weight, such as an inability to achieve successful cloacal contact during natural mating. There is also an age-related decline in fertility of broiler breeders. In attempts to prolong the fertile period of the breeders, various forms of management techniques have been employed. These include tools such as feed restriction, photoperiod management, spiking, and possibly even using artificial insemination. The first objective of this thesis was to investigate the possible benefits of feeding broiler breeder males diets containing lower crude protein levels, than given to the females, as a means of possibly tempering growth rate or improving semen quality and fertility. There was a definite improvement in the ability of the spermatozoa of the males on a lower crude protein diet to survive in the female reproductive tract. Males that received higher levels of crude protein were at a disadvantage in that fewer males yielded semen in response to abdominal massage. The second objective of this thesis was to assess the possible benefits in semen quality and fertility, when supplementing the male diets with additional vitamin E or Se in the form of Sel-Plex®. No significant effect of treatment was observed on egg fertility or semen quality.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

碩士
國立屏東科技大學
動物科學與畜產系所
103
Regardless of species of deers and region of velvet antler, the crude protein (CP) concentration in the chemical compositions of velvet antler reaches 40%-70%. Previous researches had shown that increasing dietary CP concentration might increase antler production, but also increase feed cost, nitrogen excretion and influence rumen fermentation characteristics. Therefore, the strategy of feeding high dietary CP concentration will have a negative impact on daily escalating feed cost, the concept of environment friendly and rumen health of deers. The objectives of this study were to evaluate the effects of different dietary crude protein levels and supplementation of rumen by-pass lysine on in vitro digestibilities and rumen fermentation characteristics (experiment 1) and the velvet antler production traits and in vivo digestibilities of Formosan sambar deer (experiment 2). Sixteen Formosan sambar deers were randomly assigned into 4 treatments by age, last year velvet antlers production and body condition score (BCS). Four treatments were fed with CP11%, CP11%＋0.1% rumen by-pass lysine, CP11%＋0.2% rumen by-pass lysine and CP13% TMR, respectively. The result of experiment 1 showed that inoculum from deers or cows had highly significant (P < 0.01) influences on in vitro 2 stage dry matter digestibility (DMD), organic matter digestibility (OMD), crude protein digestibility (CPD) and neutral detergent fiber digestibility (NDFD) of diets. Increasing dietary CP concentration or supplementation of rumen by-pass lysine had no significant (P = 0.21; 0.27) influences on in vitro 2 and 3 stage DMD of Formosan sambar deers; CP13% had significant (P < 0.05) highest two stage in vitro OMD and higher in vitro gas production; CP11% had higher total volatile fatty acid (total VFA). The result of experiment 2 showed that CP13% had higher total tract apparent digestibility of dry matter (DM), organic matter (OM), CP, neutral detergent fiber (NDF), and acid detergent fiber (ADF). There was no significant difference between in vitro 2 stage, 3 stage and in vivo DMD of Formosan sambar deers. CP13% had significant (P < 0.05) or higher digested N / N intake than other groups. CP13% had significant (P < 0.05) or lower Fecal N / N intake than other groups. CP11%＋0.1% rumen by-pass lysine and CP11%＋0.2% rumen by-pass lysine had significant (P < 0.05) higher length of velvet antler than CP11%. Chemical compositions and weight of velvet antler were no significant (P > 0.05) difference among groups. CP11% had significant (P < 0.05) higher concentration of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in blood. In summary of the result of experiment 1 and 2, using rumen fluid from Formosan sambar deers as inoculum to estimate it’s own in vitro 2 stage digestibility was more appropriate. Also, 2 stage in vitro DMD had no significant difference with in vivo DMD and had the advantages of time-saving, labor-saving and reducing the expense of experimental animals and benefit for the evaluation of ingredients and screening of feed formulation before animal trial. Both of increasing dietary crude protein levels and supplementation of rumen by-pass lysine can increase the length of velvet antler significantly (P < 0.05) but no significant (P > 0.05) effect on the weight of velvet antler. Key words: crude protein, digestibility, Formosan sambar deer, velvet antler

Entrotoxigenic Escherichia coli (ETEC) K88 is a causative agent of post-weaning diarrhea (PWD) in early-weaned pigs. This study investigated the efficacy of two alternative diets, charcoal (0.1, 0.5, 1, and 2%) and a low crude protein (CP) diet (17%) supplemented with probiotic E. coli strains (UM2 and UM7), against PWD infection in ETEC K88 challenged piglets. The present study found that charcoal had no effect on the challenged piglets’ performance, ileal and colonic microbiota or their fermentation end products. There was, however, a correlation between charcoal dosage and fecal consistency score. Charcoal reduced the ileal mucosal attached ETEC K88. Feeding a low-CP diet resulted in a lower ileal ammonia concentration. The low-CP diet reduced the E. coli populations in the ileal digesta as well as lowered mRNA expression of the IL-1ß. We concluded that the use of both 1-2% charcoal diet and a low-CP diet supplemented with probiotic E. coli strains were effective in reducing the incidence and severity of PWD infection.