Dissertations / Theses on the topic 'Piglets'

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 19, 2010) Thesis advisor: Dr. Marcia Shannon Includes bibliographical references.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 23, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Drs. Matthew C. Lucy and Timothy J. Safranski. Vita. Includes bibliographical references.

Thesis (M.S.) University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 27, 2007) Includes bibliographical references.

To investigate whether piglets show different personality types due to teat position, a number ofexperiments were performed on 21 different litters, 9 to 31 days old. The tests included threefocal piglets in each litter with different teat position, anterior, middle and posterior, inobservations on suckling behaviour, undisturbed behaviours, a novel object test and a straw-testwhere thirteen behaviours were observed. The tests found an effect on teat position on frequencyof disputes between piglets during suckling and their teat position (P=0.018) and a tendency ofdifference in undisturbed playing behaviour between piglets at different teat position (P=0.057).All tests found differences between litters concerning behaviours. With a Principal componentanalysis, the four personality types curiosity, playful, food interest and straw interest wasestablished. No effect between different teat positions and personality type were found, but atendency of difference between personality trait playful and different teat positions (P=0.062). Inconclusion: no significant differences between teat position and personality type in piglets couldbe established.

The objectives of the studies conducted in the Part A of this thesis were to quantify the variation of digestible energy (DE) content of wheat and to document the responsible factors for the variation. The general hypothesis tested in Part A of this thesis was that the variety, growing region, growing season, supplementation of xylanase and postharvest grain storage (i.e., six months of storage at ambient temperature) will influence the DE content of wheat when fed to weaner pigs. Experiment 1 (Chapter 3) examined the variation in the chemical composition of wheats as influenced by variety (Arrino, Westonia and Stiletto were selected), growing region (each wheat was selected from a high, medium and low rainfall region), season (1999 and 2000) and post harvest storage for 6 months. In this experiment, up to a 19% variation in the crude protein (CP) content (mean13.3, SD 2.59), up to a 5% variation in the starch content (mean 65.4, SD 3.56), and a 10-20% variation in the total (mean 9,2, SD 0.86), insoluble (mean 8.1, SD 0.84) and soluble (mean 1.1, SD 0.23) non-starch polysaccharides (NSP) contents were observed. The major experimental findings were: * Variety of wheat influenced the variation of most carbohydrate components, including fast digestible starch (FDS) (P<0.001), acid detergent fibre (ADF) (P<0.01), total and insoluble NSP (P<0.05), and in vitro extract viscosity (P<0.05); * The annual precipitation level in each region correlated to bushel weight (P<0.01), protein (P<0.01) and carbohydrate composition, including starch (P<0.05), soluble NSP (P<0.001), lignin (P<0.001) and free sugars (P<0.001), indicating the importance of the growing environment on the DE content of wheat; * Growing season influenced bushel weight (P<0.001), CP (P<0.01), amylose and amylopectin (components of starch, P<0.05), ADF (P<0.001), lignin (P<0.001), soluble NSP (P<0.001) and free sugars contents (P<0.001), and the in vitro extract viscosity of wheat (P<0.05); * Storage of wheat decreased ADF (P<0.05), lignin (P<0.01) and soluble NSP contents (P<0.01) and increased the free sugar content (<<0.001). In Experiment 2 (Chapter 4), the effect of variety, growing region and growing season on the DE content of wheat in 5-week-old male weaner pigs was examined, and Summary III correlations between various chemical composition of wheat and DE content were established. The major findings were: * The DE content of wheats varied by up to 1.3 MJ/kg (12.5 13.8; mean = 13.3) in 1999 and by up to 1.8 MJ/kg (12.6 14.4; mean = 13.7) in 2000; * Both the variety and growing region significantly influenced (P<0.05 - P<0.001) the DE content of wheat; * Generally, the wheat variety Westonia and wheats grown in the low rainfall region contained a higher DE content than other wheats and growing regions; * In addition, growing season influenced (P<0.001) DE content of wheat; * The mean DE content determined with weaner pigs in the current study was approximately 1 MJ/kg DM lower when compared to published estimates of the DE content of wheat determined with growing pigs; * Prediction of in vivo DE content of wheat for weaner pigs using NIRS (Near Infra- Red Spectroscopy) was not successful. * Significant inverse relationships between the DE content and xylose (P<0.05), NDF (P<0.01), total-P (P<0.01) and phytate-P content (P<0.05) of wheat were seen in 1999. However, such relationships were not significant in 2000, indicating a very strong seasonal influence on both chemical composition and DE content of wheat. Experiment 3 (Chapter 5) examined the effects of a supplemental enzyme (xylanase) and storage for 6 months on the DE content of wheats. In 1999, use of the enzyme tended to increase the DE content from 13.3 to 13.6 MJ/kg (P=0.065) whereas in 2000, use of the enzyme caused no change in DE content (13.7 to 13.6 MJ/kg). However, the response to enzyme addition was much greater in some wheats grown in some regions than others, suggesting that the DE response to xylanase supplementation was not systematic but appeared to be associated with the grain structure, with the DE content consequently arising from an interaction between variety and growing conditions of the wheat. For wheats harvested in 1999, storage improved the E content from 13.3 to 4.0 MJ/kg (P<0.01), but for the 2000 wheats, storage for 6 months decreased DE content from 13.7 to 13.0 MJ/kg (P<0.001). However, the 2000 data need to be interpreted with caution because some of the wheats were infested with weevils. The DE response to supplemental xylanase in 1999 was negatively correlated to the total and insoluble arabinose to xylose ratio (P<0.01), in vitro extract viscosity (P<0.01) and lignin (P<0.06), while FDS (P<0.06) and phytate-P (P<0.06) positively correlated to the DE response to xylanase. The DE response to storage in 1999 was positively correlated to the NDF (P<0.001) and xylose contents (P<0.01) of the wheats, which had negative influences on the DE content of non-stored wheats. The addition of xylanase in stored wheat did not improve the DE content, suggesting changes in chemical composition (eg, activation of xndogenous xylanases) during storage. In Experiment 4 (Chapter 6), the same wheats were analysed or phosphorus (P) and hytate-P content, as the latter is considered to be anti-nutritive in pig diets. The total P and phytate-P content of all wheat samples ranged 2.6 (s.e. .64) g/kg and 1.8 (s.e. 0.13) /kg DM, respectively. Endogenous phytase activity was highly variable and averaged 63 (s.e. 29.6) FTU/kg between wheats. The variety, rowing region, season and storage of wheat did not influence the variation of P content. However, the precipitation level over two growing seasons was positively correlated to total-P (P<0.05) and hytate-P contents (P<0.05) of wheat. Phytate-P content of wheat can be predicted from total-P content (r=0.974, P<0.001). In Part B, two experimental designs were generated based n the results of experiments described in Part A. From the previous experiment (Experiment 2, Chapter 4), it was evident that the structure of starch (i.e., amylose: mylopectin ratio) and phytate-P content of wheat were correlated to DE content of wheat. To reinforce the established correlations the following experiments were carried out, with the general hypothesis that the structure of starch (i.e., waxy vs. non-waxy wheat), particle size of ground wheat, and phytate-P content of wheat will influence the digestibility of nutrients (i.e., nitrogen, energy, minerals) in wheat-based weaner pig diets. In Experiment 5, the same variety (Janz) of a waxy (98% of total starch was amylopectin) isoline and a non-waxy isoline (71% of total starch was amylopectin) wheat were ground through a hammermill fitted either with a 8.5 mm or 4.5 mm screen to achieve average particle sizes of 930 and 560 mcm, respectively. Diets were formulated and then fed to weaner pigs (3-5 weeks of age) with or without xylanase plus beta-glucancase. Digestibilities of starch, nitrogen, energy, and DE content of diets were measured at day 7 and day 21 to examine any age-related improvement of nutrient digestibilities during the first 3 weeks post-weaning. Waxy wheat improved total tract digestibility of starch (P<0.05) and CP (P<0.05), and the reduction of particle size improved total tract starch digestibility (P<0.001) at both 7 and 21 days after weaning. However, energy digestibility and DE content of the diet were not influenced by either wheat type or particle size. Supplementation of xylanase plus ?-glucanase improved starch digestibility (P<0.01) and DE content (P<0.05) but not other nutrients, and this occurred especially in non-waxy (P=0.03) and larger particle-sized wheat (P=0.01). Pigs increased ability to digest protein with age (P<0.05). However, the improvement in nutrient digestibilities in waxy and fine particle size wheat diets did not translate to improved pig performance. In Experiment 6, the hypothesis tested was that the digestibility and pig performance responses to supplemental xylanase, phytase and xylanase plus phytase would differ in weaner pigs according to P content of wheat. To test this hypothesis, two wheats containing high and low levels of total P (2.52g vs. 3.76 g total-P/kg DM) were obtained and fed to weaner pigs. Diets either had no enzyme or were supplemented with xylanase, phytase, or a combination of xylanase plus phytase. The hypothesis was partly supported in this experiment, since P and Ca digestibility were influenced by a wheat content by enzyme ineraction. Overall improvements in macronutrient digestibility and pig performance by supplementation of various enzymes were not significant. Daily growth (P<0.05 - P<0.01) and FCR (P<0.05 - P<0.01) were improved by the supplemental enzyme only in the first week of the feeding trial, mainly due to the increased P and Ca availability induced by the enzymes. Amounts of P and Ca digested were below the recommended requirements by NRC in the first two weeks of the feeding trial. Supplementation of phytase generally improved P and Ca digestibility (P<0.05) in both low-P and high-P wheats. However, xylanase plus phytase supplementation did not produce synergistic effect for macronutrients, and mineral digestibilities, over single supplementation of xylanase or phytase. From the results obtained in this thesis I propose that: 1) The DE content of wheat for weaner pigs is variable due mainly to the change of chemical composition mediated by variety, growing environment and storage after harvest, and efficacy of supplemental xylanase is dependent on the chemical structure of NSP present in cell walls of wheat; 2) Structure of starch, particle size, age after weaning, and P content of wheat are factors influencing nutrient digestibility in weaner pigs fed a wheat-based diet, and the efficacy of phytase on P and Ca digestibilities is dependent on the phytate-P content of wheat.

The objectives of the studies conducted in the Part A of this thesis were to quantify the variation of digestible energy (DE) content of wheat and to document the responsible factors for the variation. The general hypothesis tested in Part A of this thesis was that the variety, growing region, growing season, supplementation of xylanase and postharvest grain storage (i.e., six months of storage at ambient temperature) will influence the DE content of wheat when fed to weaner pigs. Experiment 1 (Chapter 3) examined the variation in the chemical composition of wheats as influenced by variety (Arrino, Westonia and Stiletto were selected), growing region (each wheat was selected from a high, medium and low rainfall region), season (1999 and 2000) and post harvest storage for 6 months. In this experiment, up to a 19% variation in the crude protein (CP) content (mean13.3, SD 2.59), up to a 5% variation in the starch content (mean 65.4, SD 3.56), and a 10-20% variation in the total (mean 9,2, SD 0.86), insoluble (mean 8.1, SD 0.84) and soluble (mean 1.1, SD 0.23) non-starch polysaccharides (NSP) contents were observed. The major experimental findings were: * Variety of wheat influenced the variation of most carbohydrate components, including fast digestible starch (FDS) (P<0.001), acid detergent fibre (ADF) (P<0.01), total and insoluble NSP (P<0.05), and in vitro extract viscosity (P<0.05); * The annual precipitation level in each region correlated to bushel weight (P<0.01), protein (P<0.01) and carbohydrate composition, including starch (P<0.05), soluble NSP (P<0.001), lignin (P<0.001) and free sugars (P<0.001), indicating the importance of the growing environment on the DE content of wheat; * Growing season influenced bushel weight (P<0.001), CP (P<0.01), amylose and amylopectin (components of starch, P<0.05), ADF (P<0.001), lignin (P<0.001), soluble NSP (P<0.001) and free sugars contents (P<0.001), and the in vitro extract viscosity of wheat (P<0.05); * Storage of wheat decreased ADF (P<0.05), lignin (P<0.01) and soluble NSP contents (P<0.01) and increased the free sugar content (<<0.001). In Experiment 2 (Chapter 4), the effect of variety, growing region and growing season on the DE content of wheat in 5-week-old male weaner pigs was examined, and Summary III correlations between various chemical composition of wheat and DE content were established. The major findings were: * The DE content of wheats varied by up to 1.3 MJ/kg (12.5 13.8; mean = 13.3) in 1999 and by up to 1.8 MJ/kg (12.6 14.4; mean = 13.7) in 2000; * Both the variety and growing region significantly influenced (P<0.05 - P<0.001) the DE content of wheat; * Generally, the wheat variety Westonia and wheats grown in the low rainfall region contained a higher DE content than other wheats and growing regions; * In addition, growing season influenced (P<0.001) DE content of wheat; * The mean DE content determined with weaner pigs in the current study was approximately 1 MJ/kg DM lower when compared to published estimates of the DE content of wheat determined with growing pigs; * Prediction of in vivo DE content of wheat for weaner pigs using NIRS (Near Infra- Red Spectroscopy) was not successful. * Significant inverse relationships between the DE content and xylose (P<0.05), NDF (P<0.01), total-P (P<0.01) and phytate-P content (P<0.05) of wheat were seen in 1999. However, such relationships were not significant in 2000, indicating a very strong seasonal influence on both chemical composition and DE content of wheat. Experiment 3 (Chapter 5) examined the effects of a supplemental enzyme (xylanase) and storage for 6 months on the DE content of wheats. In 1999, use of the enzyme tended to increase the DE content from 13.3 to 13.6 MJ/kg (P=0.065) whereas in 2000, use of the enzyme caused no change in DE content (13.7 to 13.6 MJ/kg). However, the response to enzyme addition was much greater in some wheats grown in some regions than others, suggesting that the DE response to xylanase supplementation was not systematic but appeared to be associated with the grain structure, with the DE content consequently arising from an interaction between variety and growing conditions of the wheat. For wheats harvested in 1999, storage improved the E content from 13.3 to 4.0 MJ/kg (P<0.01), but for the 2000 wheats, storage for 6 months decreased DE content from 13.7 to 13.0 MJ/kg (P<0.001). However, the 2000 data need to be interpreted with caution because some of the wheats were infested with weevils. The DE response to supplemental xylanase in 1999 was negatively correlated to the total and insoluble arabinose to xylose ratio (P<0.01), in vitro extract viscosity (P<0.01) and lignin (P<0.06), while FDS (P<0.06) and phytate-P (P<0.06) positively correlated to the DE response to xylanase. The DE response to storage in 1999 was positively correlated to the NDF (P<0.001) and xylose contents (P<0.01) of the wheats, which had negative influences on the DE content of non-stored wheats. The addition of xylanase in stored wheat did not improve the DE content, suggesting changes in chemical composition (eg, activation of xndogenous xylanases) during storage. In Experiment 4 (Chapter 6), the same wheats were analysed or phosphorus (P) and hytate-P content, as the latter is considered to be anti-nutritive in pig diets. The total P and phytate-P content of all wheat samples ranged 2.6 (s.e. .64) g/kg and 1.8 (s.e. 0.13) /kg DM, respectively. Endogenous phytase activity was highly variable and averaged 63 (s.e. 29.6) FTU/kg between wheats. The variety, rowing region, season and storage of wheat did not influence the variation of P content. However, the precipitation level over two growing seasons was positively correlated to total-P (P<0.05) and hytate-P contents (P<0.05) of wheat. Phytate-P content of wheat can be predicted from total-P content (r=0.974, P<0.001). In Part B, two experimental designs were generated based n the results of experiments described in Part A. From the previous experiment (Experiment 2, Chapter 4), it was evident that the structure of starch (i.e., amylose: mylopectin ratio) and phytate-P content of wheat were correlated to DE content of wheat. To reinforce the established correlations the following experiments were carried out, with the general hypothesis that the structure of starch (i.e., waxy vs. non-waxy wheat), particle size of ground wheat, and phytate-P content of wheat will influence the digestibility of nutrients (i.e., nitrogen, energy, minerals) in wheat-based weaner pig diets. In Experiment 5, the same variety (Janz) of a waxy (98% of total starch was amylopectin) isoline and a non-waxy isoline (71% of total starch was amylopectin) wheat were ground through a hammermill fitted either with a 8.5 mm or 4.5 mm screen to achieve average particle sizes of 930 and 560 mcm, respectively. Diets were formulated and then fed to weaner pigs (3-5 weeks of age) with or without xylanase plus beta-glucancase. Digestibilities of starch, nitrogen, energy, and DE content of diets were measured at day 7 and day 21 to examine any age-related improvement of nutrient digestibilities during the first 3 weeks post-weaning. Waxy wheat improved total tract digestibility of starch (P<0.05) and CP (P<0.05), and the reduction of particle size improved total tract starch digestibility (P<0.001) at both 7 and 21 days after weaning. However, energy digestibility and DE content of the diet were not influenced by either wheat type or particle size. Supplementation of xylanase plus ?-glucanase improved starch digestibility (P<0.01) and DE content (P<0.05) but not other nutrients, and this occurred especially in non-waxy (P=0.03) and larger particle-sized wheat (P=0.01). Pigs increased ability to digest protein with age (P<0.05). However, the improvement in nutrient digestibilities in waxy and fine particle size wheat diets did not translate to improved pig performance. In Experiment 6, the hypothesis tested was that the digestibility and pig performance responses to supplemental xylanase, phytase and xylanase plus phytase would differ in weaner pigs according to P content of wheat. To test this hypothesis, two wheats containing high and low levels of total P (2.52g vs. 3.76 g total-P/kg DM) were obtained and fed to weaner pigs. Diets either had no enzyme or were supplemented with xylanase, phytase, or a combination of xylanase plus phytase. The hypothesis was partly supported in this experiment, since P and Ca digestibility were influenced by a wheat content by enzyme ineraction. Overall improvements in macronutrient digestibility and pig performance by supplementation of various enzymes were not significant. Daily growth (P<0.05 - P<0.01) and FCR (P<0.05 - P<0.01) were improved by the supplemental enzyme only in the first week of the feeding trial, mainly due to the increased P and Ca availability induced by the enzymes. Amounts of P and Ca digested were below the recommended requirements by NRC in the first two weeks of the feeding trial. Supplementation of phytase generally improved P and Ca digestibility (P<0.05) in both low-P and high-P wheats. However, xylanase plus phytase supplementation did not produce synergistic effect for macronutrients, and mineral digestibilities, over single supplementation of xylanase or phytase. From the results obtained in this thesis I propose that: 1) The DE content of wheat for weaner pigs is variable due mainly to the change of chemical composition mediated by variety, growing environment and storage after harvest, and efficacy of supplemental xylanase is dependent on the chemical structure of NSP present in cell walls of wheat; 2) Structure of starch, particle size, age after weaning, and P content of wheat are factors influencing nutrient digestibility in weaner pigs fed a wheat-based diet, and the efficacy of phytase on P and Ca digestibilities is dependent on the phytate-P content of wheat.

In order to investigate if difference in personality is depended on the teat positions in piglets, Sus scrofa, 63 piglets, from 21 litters, were studied. The piglets were at an age between 9 and 31 days. 3 piglets in each of the 21 litters, one that suckled at an anterior teat, one at a middle teat, and one at a posterior teat, were studied during lactation, undisturbed activity, and introduction to a novel object respectively to new straw. In total thirteen behaviors were recorded. The only significant difference between the teat position were disputes during suckling (P=0.018). There was a tendency of playing during undisturbed activity (P=0.062) between the teat positions. There were significant differences between the litters for every behavior except for inactive piglet lying alone (P=0.108) and when exploring new straw (P=0.584). There is only evidence for behavioral differences for the frequency of disputes during suckling between piglets at different teat positions. A principal component analysis, which accounted for 64.2 % of the variance, suggested four personality traits: exploration (19.2 %), playfulness (17.5 %), interest in food (14.8 %), and interest in straw (10.9 %). However, no significant differences were found for these components for the different teat positions.

Research was conducted to evaluate a novel means to euthanize piglets utilizing electromagnetic energy. Experiment 1 assessed if electromagnetic energy could result in a euthanized piglet and Experiment 2 evaluated states of consciousness of piglets. During Experiment 1, six piglets were exposed to 40 seconds of electromagnetic energy (EME). Respiration rate was reduced to zero in each piglet immediately following EME and unassisted death occurred after heart rate ceased within 4.8 minutes after EME in five of the six piglets. Treatments during Experiment 2 included EME for 3, 6, or 9 seconds. State of consciousness and treatment interaction affected (P < 0.01) electroencephalogram amplitude and power. State of consciousness affected (P < 0.01) electroencephalogram frequency and heart rate. Treatment and EME interaction also affected internal body and head surface temperatures (P < 0.01). Piglets exposed to 9 seconds EME had higher (P < 0.01) body temperature compared with other treatments.

Two trials were conducted in order to assess the efficacy of microbial phytase supplementation in improving the bioavailability of certain nutrients in the diet of early weaned piglets. In trial I, a low-phosphorus, corn-soybean meal diet supplemented with phytase significantly improved the apparent digestibilities of phosphorus (P, p = 0.0004) and calcium (Ca, p = 0.04). The average daily gain (ADG) and feed conversion ratio (FCR) were also improved by supplemental phytase. In trial II, addition of acetic acid to the low-P plus phytase diet further improved the apparent digestibilities of P and Ca (gp = 0.01, p = 0.02, respectively). Furthermore, the apparent digestibility of copper was also significantly improved by acetic acid addition. As a consequence, the piglets fed this treatment showed the best growth performance. Acidification of a diet which provided the NRC recommended levels of available P significantly improved the apparent digestibilities of protein and most of the minerals (P, Fe, Zn, Cu and Mn) but it was not reflected in improved growth performance. These results indicate that microbial phytase not only released P from the phytic acid molecule but it also cleaved other minerals bound to this complex.

En el presente trabajo se estudian diferentes estrategias de aprendizaje de la conducta alimentaria en cerdos lactantes y destetados. Los lechones podrían aprender a preferir aromas a través de su madre (Capitulo 1 y 5), por ensayo y error (Capitulo 2 y 3) o mediante interacciones sociales con otros lechones (Capitulo 4). Este aprendizaje podría mejorar la ingesta de nuevos piensos que suelen provocar neofobia. El capitulo 1 evalúa si lechones lactantes pueden reconocer y preferir claves aromáticas del liquido amniótico. Los animales fueron expuestos a un test de preferencia entre líquido amniótico materno, líquido amniótico control y agua. Otros animales escogieron entre un aroma previamente añadido a la dieta de gestación de la cerda, un aroma control y agua. Finalmente se evaluaron las preferencias por un pienso con o sin los productos aromáticos previamente añadidos al pienso de la cerda gestante. Los lechones mostraron preferencias frente al líquido amniótico de su propia madre como también frente a los aromas previamente dados a las dietas de las cerdas. Sin embargo, el contacto prenatal con estos aromas no fue suficiente para crear preferencias por el pienso que contenía el aroma. El capitulo 2 estudia el aprendizaje por ensayo y error. Los cerdos fueron entrenados a beber (30 minutos) un aroma (CS+) mezclado en una solución proteica (Concentrado proteico de soja o Péptidos Digestibles Porcinos; PDP) y otro aroma (CS-) mezclado en agua durante sesiones alternadas (6d). Los cerdos mostraron preferencias por CS+ sobre CS- en todos los test realizados. En un segundo experimento un aroma previamente condicionado fue capaz de aumentar la atracción por PDP cuando el aroma y la proteína fueron puestos juntos en la misma solución demostrando sinergia entre la preferencia por CS+ y la preferencia innata de la proteína. El capitulo 3 evalúa preferencias por aromas condicionadas a través del efecto post-ingestivo de nutrientes. Los cerdos fueron entrenados durante 8 días con un aroma (CS+) en soluciones proteicas (4%PDP) o sucrosa (4%) y con otro aroma (CS-) en soluciones con glutamato monosódico (100 mM) o sucrosa (1%) + sacarina (0.08%). Los cerdos mostraron mayores consumos de CS+ sobre CS- debido al aprendizaje asociativo entre los aromas y consecuencias post-ingestivas. El Capitulo 4 describe el aprendizaje social de conductas alimentarias en cerdos destetados. Tras diferentes experimentos, los animales mostraron preferencias marcadas por un pienso aromatizado tras interacciones sociales (30 min) con animales que habían consumido previamente el mismo pienso. Sin embargo, estas preferencias solo se visualizaron si ambos animales (el observador y demostrador) eran familiares. El capitulo 5 estudia la importancia de lácteos en las dietas post-destete y la posible influencia de una exposición pre y post-natal de PDP a través del pienso materno en el rendimiento productivo de lechones en transición. Los resultados no muestran diferencias entre lechones alimentados con dietas con productos lácteos (suero de leche 14%) o con dietas sin estos productos y PDP (2%). Sin embargo, los animales mostraron una mayor preferencia y aceptación por la dieta que tenía lácteos (Test de preferencia y de aceptación de 30 minutos). Cuando se utilizo la estrategia de añadir el PDP a las dietas de la cerda, los animales mostraron una tendencia a presentar mayores ganancias y consumos que cerdos control (15-33d post-destete). Como conclusión se puede decir que los cerdos son capaces de preferir claves aromáticas a través del aprendizaje asociativo previo de estas claves con las consecuencias positivas del líquido amniótico, nutrientes y contacto social. Esto podría incrementar las opciones que los cerdos tienen de adaptarse frente a nuevas claves sensoriales en un pienso.
The present work studies different learning strategies to increase the preference for flavours cues during lactation and after weaning. We propose that pigs may learn flavour preferences from their mother (Chapter 1 and 5), from trial and error tasks (Chapter 2 and 3) or from social interactions with conspecifics (Chapter 4), and that this learning may improve intake of new diets. Chapter 1 evaluate if piglets have the ability to prefer cues of maternal amniotic fluid after birth. During 7 minutes piglets couples were tested to prefer between maternal amniotic fluid, alien amniotic fluid and water or between a flavour added into late gestation maternal diet, a control flavour and water. The same prenatal strategy was used to study piglet’s preferences for flavoured or unflavoured creep feed during the suckling period. Suckling piglets preferred the amniotic fluid from their own mother over an alien amniotic fluid and also they preferred flavours cues given to the sows during the gestation period. However, prenatal flavour exposure did not created feed preferences during lactation. Chapter 2 study if piglets could learn by trial and error to prefer a new flavour cue. Animals were trained to drink (30min/day) one flavour (CS+) mixed into 2% protein solution (Soybean-Protein-Concentrate or Porcine-Digestible-Peptides; PDP) and another flavour (CS-) mixed into water during 6 alternate sessions. Animals preferred the CS+ over the CS- flavours at all test days. No differences were observed between proteins. In a second experiment a conditioned flavour preference also enhanced the attraction to a protein (PDP) when the flavour and protein were combined showing a synergy effect between the CS+ and US attraction. Chapter 3 evaluate flavour preferences conditioned by the post-ingestive effect of nutrients. Pigs were trained during 8d with one flavour (CS+) into PDP or sucrose solutions on odd days and another flavour (CS-) into 100 mM of monosodium glutamate (MSG) or 1% sucrose + 0.08% saccharine solutions on even days. Piglets showed higher intakes for CS+ than CS- explained because an associative learning between flavours and post-ingestive effects of nutrients. Chapter 4 describes social learning of feeding behaviour in pigs, in which a naive animal could learn specific flavour preferences by a close and brief contact with a conspecific. Piglets showed a preference for flavoured feed following social interactions (30 minutes) with an experienced demonstrator that ate that flavour before. However, higher intakes of demonstrators consumed flavoured feed were observed only when demonstrators and observers were familiar. Chapter 5 study the importance of milky flavour continuity in the post-weaning period and explore the influence of pre and postnatal exposure to PDP via maternal diet on the productive performance of post-weaned piglets fed a diet containing the same protein. No differences were found between the productive parameters of animals fed with dairy or PDP diets. However, animals showed a higher preference and acceptance for diets containing dairy products than for PDP diets (30 minutes choice and one feeder test). When the PDP was added to sows diets, post-weaned piglets tended to show higher ADFI and ADG than control piglets (15-33d after weaning). It is concluded that pigs may learn to prefer neutral flavours cues by a previous associative learning with a positive consequence. Flavour preferences learned through maternal transference, associative learning with nutrients and social interactions could increase pigs options to fit against new environment feed cues. These three ways of learning could act also together increasing the adaptive value of the learned feed.

Five experiments were designed to investigate factors affecting the creep feeding of suckling piglets and a preliminary method to monitor the creep feeding of suckling piglets was developed. In experiment 1, neonatal viability and creep feeding behaviour on d 14-15 were monitored. Birth weight rather than birth order affected the neonatal viability in terms of cumulative suck number (P< 0.01). The lighter piglets at birth went to contact the feeder faster (P< 0.10), but tended to touch the food slower (P< 0.10) on dl4 when creep food was introduced. Neither birth weight or birth order affected the creep feeding behaviour over 24 hours on d 14-15. The relationship between neonatal viability and creep feeding behaviour was not consistent and clear. In Experiment 2 and 3 the effect of hunger was studied after piglets were made hungry by preventing nursing twice. The hungry piglets showed more foraging behaviour (P< 0.05) and more general activity (P< 0.05) when they first encountered creep food in the test pen on dl7. More of the hungry piglets in Experiment 2 ate creep food in the test pen than those not hungry (P< 0.05). However these effects were not repeated on the following day. Food type did not affect any foraging behaviour and general activity in Experiment 3. In the Experiments 2 and 3, after the test until the weaning day on d28, creep food intake varied between litters but neither feeding time nor growth of piglets varied amongst treatments. There was no clear correlation between the foraging behaviour in the test pen and the creep feeding behaviour in the home pen.

Foetal piglets do not obtain immunoglobulins during pregnancy and rely on colostrum immunoglobulins until active immunity develops. The amount of immunoglobulin that piglets obtain depends upon: colostrum immunoglobulin concentration; quantities of colostrum ingested and when closure occurs. Closure describes the change that takes place between 12-36h of life, when the piglet gut can no longer absorb immunoglobulins. A series of studies were undertaken to examine colostrum IgG concentrations and IgG acquisition by piglets. The first two trials demonstrated that IgG concentration between sows and piglet IgG intake was very variable. Piglet plasma IgG concentrations were remarkably consistent however, suggested that piglets were regulating IgG uptake. The third trial reduced piglet IgG intakes by delaying suckling. Results showed that piglets with reduced IgG intakes had reduced plasma IgG concentrations and could not compensate for lowered IgG intake. The results suggested that piglets regulated IgG uptake when IgG was in excess, but had only limited ability to regulate IgG uptake when IgG supply was limited. The fourth trial set out to examine the effects of maternal diet and vaccination on piglet IgG acquisition. A 2x2 factorial design, sows were fed diets either with vitamins A, C and E at recommended amounts or 3-5 times recommended amounts and either vaccinated or not. Results showed that maternal vaccination or diet did not affect maternal plasma IgG concentration or colostrum IgG concentration. Supplementing maternal diet with vitamins significantly increased piglet plasma IgG concentrations, as did maternal vaccination. Of ingested IgG, approximately 0.6-0.7 appeared in piglet plasma. It was possible to influence piglet plasma IgG concentrations by manipulating maternal diet and immune status. With increasing pressure on the use of antibiotics in agriculture and increasing animal welfare/health demands, the effects of other macro and micronutrients on piglet IgG status need to be investigated.

Thesis (PhD)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: This study describes the use of a gastro-intestinal model to screen lactic acid bacteria isolated from the gastro-intestinal tract of post-weaned piglets (raised on six different diets) for probiotic properties. Intestinal bacteria were isolated from ,the stomach, duodenum, jejunum, caecum, ileum and colon. The highest cell numbers (6 x 107 cfulg) were isolated from the ileum. No significant differences in viable cell counts were recorded for piglets raised on the six diets. Isolates with the best overall probiotic properties were identified as members of Lactobacillus salivarius and Lactobacillus fermentum. The two strains selected for further studies were Lactobacillus plantarum 423 (originally isolated from sorghum beer) and Lactobacillus salivarius 241 (isolated from pig intestine). Enterococcus faecalis FAIR E 92 was originally isolated from pig intestine and was included in this study as a non-pathogenic challenge strain. L. plantarum 423 produces a bacteriocin plantaricin 423, active against E. faecalis FAIRE 92. L. plan/arum 423 and L. salivarius 241 were included in the gastro-intestinal model and their adhesion to the mucus of porcine ileum studied with fluorescent-in-si/u-hybridization (FISH). A decrease in viable cell numbers of L. plan/arum 423 was recorded in the duodenum, jejunum and ileum in the presence of bile and pancreatic juice. However, higher cell numbers were recorded in the caecum and anterior colon, which suggested that strain 423 recovered from these stress factors. Plantaricin 423 was detected for up to 28 hours in the duodenum, jejunum, ileum and middle colon. Lower cell numbers (one log unit) of L. salivarius 241 were recorded in the gastro-intestinal model over seven days, compared to strain 423. Piglets of one, 14 and 28-days-old were dosed with L. plan/arum 423 and L. salivarius 241, separately and in combination (1: 1). In a separate experiment, 14-day-old piglets were challenged twice with E. faecalis FAIRE 92, followed by dosage with strains 423 and 241. New-borne piglets dosed with L. plantarum 423 gained more weight (4 kg over 19 days) compared to piglets dosed with L. salivarius 241 (2.2 kg over 19 days), or a combination of the two strains (2 kg over 19 days). Piglets of 14 and 28-days-old, on the other hand, gained more weight when dosed with a combination of strains 423 and 241. The cell numbers of E. faecalis FAIR E 92 and other enterococci decreased drastically (two log units) when the piglets were dosed with the latter two strains. Overall, piglets of various ages reacted differently when administered L. plantarum 423 and L. salivarius 241, separately or in combination. Fluorescent-in-situ-hybridization (FISH) was used to study the in vivo adhesion of L. plantarum and L. salivarius to mucus in the stomach, duodenum, jejunum, ileum, caecum and colon. The highest number of L. plantarum cells was recorded in the ileum, whereas L. salivarius favoured adhesion to the duodenum. A decrease in cell numbers of E. faecalis in the ileum mucus was recorded when a combination of the probiotic strains 423 and 241 was administered. This study provided a reliable estimation of the presence and/or adhesion of L. plantarum and L. salivarius to various parts of the porcine gastro-intestinal tract, without the use of expensive cultivation techniques. Insight was gained into the co-evolution existing between probiotic bacteria and the porcine gastro-intestinal tract, emphasizing the use of gastro-intestinal models to study the dynamics of the gastro-intestinal tract.
AFRIKAANSE OPSOMMING: Hierdie studie beskryf die gebruik van 'n gastro-intestinale model, om melksuurbakterieë wat geïsoleer is uit die spysverteringskanaal (SVK) van reeds gespeende varkies (gevoed op ses verskillende diëte) vir probiotiese eienskappe te toets. Ingewandsbakterieë is uit die maag, duodenum, jejunum, caecum, ileum en kolon geïsoleer. Die hoogste aantal selle (6 x 107 kve/g) is geïsoleer uit die ileum. Geen betekenisvolle verskille in lewensvatbare seltellings, vir varkies gevoed op ses verskillende voere is aangeteken nie. Isolate met die beste algehele probiotiese eienskappe is as Lactobacillus salivarius en Lactobacillus fermentum geïdentifiseer. Vir verdere studie is twee isolate Lactobacillus plantarum (oorspronklik uit sorghum-bier geïsoleer) en Lactobacillus salivarius (uit die varkdermkanaal geïsoleer) geselekteer. Enterococcus faecalis FAIRE 92, oorspronklik uit die varkdermkanaal geïsoleer, is in hierdie studie as 'n nie-patogeniese indikator gebruik. L. plantarum 423 produseer 'n bakteriosien plantarisien 423 wat aktief is teen E. faecalis FAIR E92. L. plantarum 423 en L. sa/ivarius 241 is ingesluit in die gastro-intestinale model, en vashegting van die bakterieë aan die mukus van vark-ileum is met fluoresensie-in-si/uhibridisasie (FISH) bestudeer. 'n Afname in lewende selgetalle van L. plan/arum 423 in die duodenum, jejunum en ileum is aangetoon in reaksie tot die byvoeging van gal en pankreatiese sappe. Hoër selgetalle is nietemin aangeteken in die caecum en voorste gedeelte van die kolon, wat 'n aanduiding gee dat isolaat 423, ten spyte van hierdie stres-faktore, oorleef. Plantaricin 423 is vir 'n tydperk (28 uur) in die duodenum, jejunum, ileum en sentrale kolon gevind. Laer selgetalle (een logaritmiese eenheid) van L. salivarius 241 is in die gastro-intestinale modeloor 'n tydperk van sewe dae aangetoon, in vergelyking met isolaat 423. Een, 14 en 28 dag oud varkies is met L. plantarum 423 en L. salivarius 241 (afsonderlik en in kombinasie 1:1) twee keer gedaag met E. faecalis FAIR E 92, opgevolg met dosering van 423 en 241. Pasgebore varkies het die hoogste gewigstoename getoon (4 kg oor 19 dae) na dosering met L. plantarum 423 in vergelyking met varkies gedoseer met L. salivarius 241 (2.2 kg oor 19 dae) of 'n kombinasie van die twee isolate (2 kg oor 19 dae). Daarenteen het veertien- en 28 dag oud varkies beter gewigstoename getoon na dosering met 'n kombinasie van isolate 423 en 241. Die selgetalle van E. faecalis FAIRE 92 en ander enterococci het drasties afgeneem (twee logaritmiese eenhede) nadat die varkies met laasgenoemde twee isolate gedoseer is. Varkies van onderskeie ouderdom het verskillend gereageer na dosering met L. plantarum 423 en L. salivarius 241 afsonderlik of in kombinasie. Fluoresensie-in-situ-hibridisasie (FISH) is gebruik om die in vivo vashegting van L plantarum en L. salivarius tot die vark mukus in die maag, duodenum, jejunum, ileum, caecum en kolon te bestudeer. Die hoogste telling van L. plantarum selle is aangeteken in die ileum, terwyl L. salivarius aanhegting tot die duodenum verkies het. 'n Afname in seltellings van E. faecalis in die ileum mukus was aangeteken na toediening met 'n kombinasie van probiotiese isolate 423 en 241. Hierdie studie het 'n betroubare bepaling van die voorkoms en/ofvashegting van L. plantarum en L. sa/ivarius isolate in verskeie gedeeltes van die varkspysverteringskanaal voorsien, sonder die hulp van duur kwekings tegnieke. Probiotiese bakterieë is in 'n gastro-intestinale model, wat die natuurlike omgewing verteenwoordig, bestudeer. Insig oor die ko-evolusie tussen probiotiese bakterieë en die SVK van die vark is verkry. Die gebruik van 'n gastro-intestinale model om die dinamika van die SVK te bestudeer is met hierdie studie beklemtoon.

A programme of study was undertaken to asses the antimicrobial and potential immunological properties of fermented liquid feed fed to sows in late gestation period. A liquid feed fermented with Lactobacillus plantarum fed to the pregnant sow in late gestation had the potential to beneficially modify the microflora the lactating sows introduces into the environment, which was consequently reflected in beneficial changes in the gut microflora of their litters. In addition, colostrum from sows fed FLF had a significantly greater mitogenic activity on both intestinal ce11s (79326 ± 3069 CPM) and blood lymphocytes (1903 ± 204 CPM) compared with colostrum from dry feed fed sows (53433 ± 1568 CPM and 1231 ± 61.4 CPM respectively). The combined effects of higher milk quality and the reduction in the level of environmental contamination with faecal pathogens, achieved by FLF, may be important in achieving improved health status for both sows and piglets. A series of in vitro experiments were conducted in order to select a suitable new starter culture from LAB of porcine origin, which would have similar fermentative abilities to Lactobacillus plantarum, but could exert possible 'probiotic' effects on the host (pregnant sow). From a total of 87 faecal Lactobacillus strains, a homofermentative aggregating Lactobacillus salivarius, was selected for further in vivo studies as it was able to resist bile and acid conditions, had good adherence abilities to a11 intestinal compartments (mucus, epithelial cells, collagen), as well as being a potent stimulator of interleukin (IL)-12. In addition, it had comparable fermentation properties to the Lactobacillus plantarum that has been widely used to ferment FLF in this laboratory. In vivo experiments with porcine Lactobacillus salivarius strongly indicated that this bacterial strain is an effective inoculant for FLF, with a potential double role: the role of the starter culture and the role of probiotic. This could help sows to overcome disorders due to the stress associated with farrowing, enhance immunity of newborn piglets through better immunological quality of colostrum and control pathogen challenge for both sows and their newborn piglets.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Foram conduzidos dois ensaios para avaliar a utilizaÃÃo do farelo de arroz parboilizado (FAP) como ingrediente em raÃÃes para leitÃes na fase de creche. No primeiro ensaio foram utilizados 14 leitÃes machos castrados de mesma linhagem comercial, com peso inicial de 17,2Â1,02 kg, para a avaliaÃÃo nutricional do farelo de arroz parboilizado em ensaio de digestibilidade, utilizando o mÃtodo de coleta total de fezes. O delineamento experimental utilizado foi inteiramente casualizado, sendo dois tratamentos (raÃÃo referÃncia e raÃÃo teste) e sete repetiÃÃes por tratamento, sendo a unidade experimental constituÃda por um animal. O farelo de arroz parboilizado apresentou 2321,08 kcal EM/kg e 17,15%PB. No segundo ensaio foram utilizados 60 leitÃes machos castrados, de linhagem comercial, desmamados aos 21 dias de idade e com peso vivo de 6,40  0,79 kg, com o objetivo de avaliar o efeito de diferentes nÃveis inclusÃo do farelo de arroz parboilizado sobre o desempenho zootÃcnico, ocorrÃncia de diarreia e viabilidade econÃmica, dos 21- 32 dias de idade, 21- 42 dias de idade e 21- 63 dias de idade. O delineamento experimental utilizado foi em blocos casualizados, com cinco tratamentos (0; 4; 8; 12 e 16% de inclusÃo do FAP), e seis repetiÃÃes por tratamento, sendo a unidade experimental constituÃda por dois animais. A formaÃÃo dos blocos foi feita atravÃs do peso inicial dos animais. NÃo houve diferenÃa (P>0,05) entre o tratamento controle e os tratamentos que receberam a inclusÃo do farelo de arroz parboilizado quando comparados pelo teste de Dunnett (5%), assim como para a anÃlise de regressÃo, onde nÃo foram observados efeitos (P>0,05) entre os nÃveis de inclusÃo do farelo de arroz parboilizado nas raÃÃes para nenhuma das variÃveis de desempenho zootÃcnico (consumo de raÃÃo mÃdio diÃrio, ganho de peso mÃdio diÃrio e conversÃo alimentar). A inclusÃo dos diferentes nÃveis do farelo de arroz parboilizado nÃo proporcionou aumento na incidÃncia de diarreia nos leitÃes. Para a anÃlise econÃmica realizada, a inclusÃo do farelo de arroz parboilizado mostrou-se viÃvel atà o nÃvel de 16%. Conclui-se que o farelo de arroz parboilizado pode ser incluÃdo atà o nÃvel de 16% em raÃÃes para leitÃes na fase de creche.
Two assays were conducted to evaluate rice bran parboiled as an ingredient in piglet diets at nursery phase. In the first assay, 14 piglets of commercial lineage with 17 . 2 Â 1 . 02 kg of body weight were allotted to determine the nutritional value of rice bran parboiled on digestibility assay, using the method of total collection of feces . A complet ely randomized design, with two treatments (reference ration and test ration) and seven replicates per treatment were used , where the experimental unit consisted of one animal. The parboiled rice bran presented 2321 . 08 kcal ME/ kg and 17 .15 % of CP . In the second assay, 60 male castrated piglets , of commercial lineage, weaned at 21 days of age and average live weight of 6 . 40 Â 0 . 79 kg, were used to evaluate the effect of inclusion of different levels of parboiled rice bran in piglet diets at nursery phase, on productive performance, d iarrhea incidence and economic viability, of 21 - 32 days of age, 21 - 42 days of age and 21 - 63 days of age. A randomized block design was used , with 5 treatments (inclusion levels of parboiled rice bran: 0; 4; 8; 12 and 16%) and 6 replicates per treatment, where the experimental unit consisted of two animals. The blocks were made using the initial weight of the animals. There was no d ifference (P>0 . 05) between treatments and control treatment with the inclusion of parboiled rice bran when compared by Dunnett's test (5%), as well as regression analysis, where no effects (P>0 . 05) were observed among the levels of inclusion parboiled rice bran in diets in any of performance variables (daily mean feed intake, daily mean weight gain and feed conversion). The results indicated that the inclusion of parboiled rice bran provided no changes in the incidence of diarrhea in animals. The economic analysis showed no significant difference among treatments. Therefore, it can be co ncluded that parboiled rice bran can be included up to 16% in diets for piglets at nursery phase.

Surgical castration of piglets is a high topic due to the higher attention of both the consumers and the public opinion on the animal welfare. The management practice is usually performed for the reduction of aggressiveness in adult subjects and to preserve meat from boar taint, a sensory defect caused by the sexual hormone androstenone and the intestinal catabolite skatole. The “European declaration on alternatives to surgical castration”, signed in 2011 by all the principal actors of swine production system, require the abandon of surgical castration from the 1st of Jenuary 2018;moreover, the Declaration still recognizes the inevitability of mutilation in the case of pigs for the production of meat registered under "traditional specialties guaranteed" or with "geographical indications" (Protected Geographical Indication (PGI) or Protected Designation of Origin (PDO)), that represent the majority of Italian pig production. In any case, for such production, alternatives to surgical castration with analgesia and/or anaesthesia should be introduced. The choice of the most effective drugs is strictly connected to the degree of pain experienced by piglets. Although many studies demonstrated the presence of pain due to castration regardless pigs age, no standard method for the pain assessment exist yet, and consequently there are not method to evaluate its reduction using drugs. In the first three chapter of the present work different methods for pain assessment were tested both physiological/emetic and behavioural, comparing piglets subjected to surgical castration to handled piglets. Among tested parameters the analysis of blood cortisol, considered the most important stress hormone, revealed a pick in castrated piglets within the first hour after mutilation, demonstrating to be a useful parameter to evaluate differences between the two group just immediately post mutilation. The analysis of blood lactate and glucose after the painful stimulation did not underline the expected increase as well as body temperature which revealed differences between castrated and handled just 3 hours after the treatment, probably due to a voluntary longer permanence of mutilated piglets under the heat lamp in the nest. The measurement of eye temperature through the use of a infrared thermacam, never used before in a similar study, pointed out a temperature higher in castrated piglets. Among behavioural parameters, mutilated piglets needed more time to start walking when placed back to the farrowing crate, and they demonstrated alterations in posture and walking up to one hour after the mutilation. The evaluation of facial expression, method widely used in human unconscious patient and infants as well as recently in laboratory animals as mouse, rats and rabbit but never in pigs, revealed a major presence of check tension in castrated subjects in comparison to manipulated ones. The last chapter focused on the effect of a non steroidal anti-inflammatory drug through the analysis of blood cortisol and of general behaviour recorded using the scan sampling method. Tolfenamic acid demonstrated its utility in the reduction of pain locating treated piglets in intermediated levels between piglets castrated without drugs and handled piglets both as cortisol level and time used performing different behaviours. Concluding, the evaluation of pain in pigs is of difficult interpretation, but the combination of different methods seems to give useful indications to study drug efficacy for the reduction of such a pain.
La castrazione chirurgica dei suinetti è un argomento di elevata attualità data l’attenzione sempre più elevata dei consumatori, e quindi dell’opinione pubblica, in tema di benessere animale. Tale pratica zootecnica viene routinariamente effettuata per la riduzione dell’aggressività nei soggetti adulti e per preservare le carni del cosiddetto “odore di verro”, difetto sensoriale causato dall’ormone sessuale androstenone e dal catabolita intestinale skatolo. La “Dichiarazione volontaria di abbandono della castrazione”, sottoscritta nel 2011 da tutti i principali attori della filiera suinicola dei diversi stati europei, impone l’abbandono della pratica chirurgica a partire dal 1 Gennaio 2018, ma riconosce la necessità della mutilazione per la produzione di prodotti di alta qualità quali DOP e IGP, destino della maggior parte della produzione suinicola italiana. Per le realtà produttive esonerate dall’obbligo di abbandono è comunque previsto l’utilizzo di anestesia e/o analgesia prolungata. La scelta dei farmaci più efficaci a tale scopo è strettamente vincolata alla valutazione del grado di dolore provato dai suinetti. Attualmente, però, nonostante numerosi studi dimostrino la presenza di dolore associato alla pratica a prescindere dall’età in cui venga effettuata, non esistono metodi standard per valutarne l’intensità e conseguentemente l’eventuale riduzione derivante dall’utilizzo di farmaci. Nei primi tre capitoli del presente lavoro sono stati testati diversi metodi di valutazione del dolore sia di carattere fisiologico/ematico che di carattere comportamentale confrontando suini sottoposti a castrazione chirurgica e suini in cui la pratica veniva simulata. Tra i diversi parametri testati la valutazione del cortisolo ematico, considerato ormone dello stress per eccellenza, ha rilevato un picco nei suini castrati rispetto ai non castrati unicamente entro la prima ora dal trattamento, dimostrandosi un parametro utile ai fini delle differenze tra trattamenti solo nell’immediato post castrazione. L’analisi ematica di lattato e glucosio in seguito alla stimolazione dolorifica non ha evidenziato l’innalzamento previsto, così come la temperatura corporea ha rivelato delle differenze tra suini sottoposti a castrazione o manipolati solo a 3h dal trattamento, probabilmente a causa di una maggior permanenza volontaria dei suini doloranti sotto la lampada riscaldante del nido. Il rilevamento della temperatura oculare attraverso l’utilizzo di una termocamera a infrarossi, mai utilizzata prima d’ora con questo scopo, ha invece evidenziato una temperatura tendenzialmente più elevata nei suini mutilati. Tra le valutazioni di carattere comportamentale, i suini castrati impiegavano più tempo a riprendere a camminare appena appoggiati nella gabbia parto, e dimostravano alterazioni in posture e atteggiamenti fino a un’ora dopo la mutilazione. La valutazione delle espressioni facciali, metodica ampliamente utilizzata nei pazienti umani incoscienti e nei neonati nonché ultimamente negli animali da laboratorio quali topi ratti e conigli ma mai nei suini, ha rivelato una maggior presenza di tensione a livello guanciale nei soggetti castrati rispetto ai manipolati. L’ultimo capitolo, attraverso l’analisi del cortisolo ematico e del comportamento generale valutato mediante tecnica dello scan sampling, si è concentrato sull’effetto di un farmaco antiinfiammatorio non steroideo. L’ acido tolfenamico si è dimostrato utile nella riduzione del dolore, localizzando i suini trattati col farmaco a livelli intermedi tra i castrati senza farmaco e i manipolati sia come valori di cortisolo sia come tempo impiegato nei diversi comportamenti. Concludendo, la valutazione del dolore negli animali, e nei suini nello specifico, è tutt’altro che di facile interpretazione, ma l’accostamento di diversi metodi sembra poter fornire indicazioni utili allo studio sull’efficacia di farmaci destinati alla riduzione di tale sofferenza.

La mortalitat durant la lactació és probablement el major problema econòmic i de benestar a afrontar per les explotacions porcines. Davant aquesta problemàtica, el principal objectiu d’aquesta tesis doctoral és intentar identificar els principals aspectes que poden contribuir a incrementar la supervivència dels garrins durant la lactació i, al mateix temps, identificar i jerarquitzar les tasques de maneig més efectives realitzades al voltant del part. Quatre estudis s’han dissenyat per assolir els nostres objectius (chapter 4, 5, 6 and 7): Al primer estudi, es van portar a terme dos experiments per estudiar l’efecte sobre truges primípares i les seves garrinades que s’observa després d’allotjar les truges en grup durant la gestació i mantenir-les lleugerament sobrealimentades (PEN, n = 27 per Exp. 1; n = 10 per Exp. 2) en comparació a tenir-les en gàbies convencionals (STALL, n = 24 per Exp. 1, n = 9 per Exp. 2). Es va mesurar la grassa dorsal (BF) al inici i final de la lactació i es va registrar la mortalitat. Els garrins es van pesar i es va registrar la seva temperatura rectal (RT). Per l’Exp. 1 es va enregistrar el comportament d’un subgrup de truges. Per l’Exp. 2 es van analitzar cortisol salivar de les truges i la concentració en sang de TSH i T4 dels garrins. Les truges del grup PEN van mostrar major BF a l’inici de la lactació (P < 0.001). Es va observar una tendència a major concentració de cortisol en les truges del grup PEN a les 24 h d’estar a les gàbies de part (P = 0.070) i una tendència a passar-se més temps assegudes o dempeus la jornada anterior al part (P = 0.057). Els garrins nascuts al grup PEN van tenir nivells menors de T4 (P = 0.078). No obstant, els garrins del grup STALL tingueren major RT als 60 min de vida (P < 0.05) i van sobreviure en més nombre després de les primeres 48 h de vida fins al final de la lactació (P < 0.05). A l’Exp. 2, els garrins del grup STALL pesaven més (P < 0.05) i van tenir un guany mig diari durant lactació més elevat (P < 0.05). Les truges nul·lípares allotjades en grup i lleugerament sobrealimentades durant la gestació es veuen sotmeses a un major estrès al ser introduïdes a les gàbies de maternitat que les truges allotjades en gàbies convencionals durant la gestació. Aquest estrès matern pot comprometre la capacitat de termoregulació dels seus garrins. L’objectiu del segon experiment va ser el de desenvolupar, a partir del seu comportament, un sistema d’avaluació de la vitalitat dels garrins que guardés relació amb el seu posterior creixament i supervivència. Es van emprar 287 garrins provinents de 21 truges multípares. Els garrins es van pesar acabat el part i es van avaluar 4 paràmetres comportamentals en un petit tancat circular de 55 cm de diàmetre: capacitat de moviment (U), estimulació del braguer (U), nombre de voltes completes dins el tancat (N), i capacitat de cridar (S). A dia 1, 2, 3 i 17 es van pesar els garrins, i a dia 1, 2 i 3 se’ls hi va mesurar la RT. Es van realitzar anàlisis de regressió múltiple per la supervivència i creixement dels garrins fins el deslletament. El guany de pes dels garrins durant la lactació va estar influenciat pel pes al naixement (P < 0.001), el número de part de al truja (P = 0.024), el número de nascuts vius al part (P < 0.001), i pel sumatori dels paràmetres U i N (UN; P = 0.023). La capacitat de sobreviure dels garrins va ser influenciada pel pes al naixement (P = 0.015), pel paràmetre UN (P = 0.026), i per la RT a dia 3 (P = 0.085). El sumatori de la valoració als paràmetres U i N, combinats amb el pes al naixement i la informació de la truja, són útils per ajudar a predir el potencial de creixement i la viabilitat del garrí durant la lactació, convertint-se en una possible eina per millorar el maneig durant els primers dies de vida dels garrins. Resumint, el paràmetre UN és fàcil d’obtenir i pot ser d’utilitat per avaluar els garrins tant per criteris científics com productius. El tercer estudi està centrat en estudiar diferents mesures de maneig orientades a maximitzar la presa de calostre per part dels garrins. Es van utilitzar 39 truges primípares (507 garrins) i 100 multípares (1375 garrins). Els garrins es van classificar en: nascuts amb un pes de 1.30 kg o inferior (SP) i nascuts amb un pes superior a 1.30 kg (BP). Les garrinades es va distribuir a un dels 4 tractaments: grup control (CON); deixar que els SP mamin durant 2 h separant els BP (SPLIT); subministrar oralment 15 ml de calostre de truja als SP (COL); i subministrar 3 ml d’un producte energetic (Calostrene®) als SP (EN). Es van fer el mínim d’adopcions, ajustant les garrinades a 12 garrins (mantenint 4 o 5 SP a cada garrinada). Els garrins es van pesar al dia 1 i 18 de vida, i es va registrar la mortaitat. En les garrinades de primípares, els SP del grup COL van pesar més que els de CON, SPLIT i EN a les 24 h de vida (dia 1) (P = 0.020, P = 0.022, and P = 0.046, respectivament). Malauradament, aquesta diferència no es va observar a dia 18. En les garrinades de multípares no es van observar diferències de pes durant la lactació entre els diferents grups. Tot i que entre les garrinades de primípares i multípares els SP no diferien en pes al naixement, a dia 1, els SP de primípares eren més pesats (P = 0.020). Malgrat aquestes circumstàncies, no es va reduir la mortalitat a les garrinades del grup COL (ni en primípares ni en multípares). La complementació oral millora el guany de pes durant el primer dia de vida dels garrins SP nascuts de primípares, però no ajuda a reduir la mortalitat durant la lactació. En el quart i últim experiment es va estudiar l’efecte d’aportar calostre als garrins nascuts amb un pes igual o inferior a 1.35 kg (SP) (CON: grup control; COL:subministrar oralment 15 ml de calostre de truja), i l’efecte de realitzar adopcions a les 24 h (HL: ajustar garrinades a 12 garrins amb 4 o 5 essent SP; o LL: majoria dels garrins de al garrinada essent SP). Combinant els dos factors s’obtingueren 4 tractaments: CON-HL, CON-LL, COL-HL, COL-LL. Els garrins de 46 garrinades es van pesar també a dia 1 i 19, i la mortalitat es va registrar. Al dia 4 de vida, es va extreure sang de 79 garrins SP per analitzar la concentració d’IgG, i també de 8 garrins SP separats de la truja durant 12 h i alimentats artificialment que es van utilitzar com a control negatiu. Les garrinades LL tenien un CV del pes a dia 1 menor comparat amb el grup HL (16.2 vs. 21.9 ± 0.91%, P = 0.003), però no diferien pel mateix paràmetre a dia 19 (23.2 vs. 23.4 ± 1.72%; P > 0.10). A dia 19, les truges HL van tenir menys garrins morts per garrinada que les truges LL (0.80 vs. 1.69 ± 0.307; P = 0.022) i les truges del grup COL-HL van tenir menys garrins morts per garrinada que les CON-HL (0.47 vs. 1.14 ± 0.160; P = 0.062). Les adopcions dels SP per formar garrinades LL no va aconseguir reduir el CV de pes de al garrinada al deslletament. Els garrins del grup COL van tenir major concentració de IgG que els del grup CON (P = 0.001); mentre que el grup control negatiu va tenir nivells de IgG inferiors a COL i CON (5.4 ± 2.32 mg/ml vs. 30.6 ± 1.58 mg/ml and 21.5 ± 0.95 mg/ml. respectively; P < 0.001 ambdós casos). Fer ‘garrinades de petits’ no va reduir la mortalitat ni va reduir el CV del pes de la garrinada. Donar calostre als garrins SP millora el seu estatus immunitari a dia 4. A més a més, en garrinades no homogeneïtzades, aportar calostre als garrins SP és una bona estratègia per millorar el seu rendiment.
Pre-weaning mortality in breeding herds remains as one of the most important welfare and economic problems in swine production. Therefore, the principal objective of the present thesis was to identify the main aspects that may help to reduce on-farm piglet pre-weaning mortality and to establish a management hierarchy identifying the most effective tasks around farrowing. To achieve our objective, four studies were performed (chapter 4, 5, 6 and 7): In the first study, two experiments were carried out to observe the effect of two gestation management systems (STALL: gilts housed in stalls with no changes in management, and PEN: slightly overfed gilts loose-housed in pens) on gilt and piglet performance. A total of 27 PEN and 24 STALL gilts and 10 PEN and 9 STALL gilts were used in Exp. 1 and Exp. 2, respectively. Backfat (BF) at the beginning and at the end of lactation, and litter pre-weaning mortality were recorded in gilts. Weight and rectal temperature (RT) was recorded in piglets. In Exp. 1 the behaviour of a subsample of gilts was continuously videotaped during lactation. In Exp. 2 cortisol in gilt saliva, and TSH and T4 in piglet blood were measured. In both experiments, PEN gilts had more BF than STALL gilts when moved to the farrowing stalls (P < 0.001). PEN gilts tended to have higher cortisol concentration 24 h after entering the farrowing stall (P = 0.070) and to spend more time sitting or standing up 1 day before parturition (P = 0.057) than STALL gilts. Piglets from PEN gilts had lower T4 (P = 0.078) than those from STALL gilts. However, piglets from STALL gilts showed higher RT 60 min after birth (P < 0.05) and lower mortality from 48 h after of birth until weaning (P < 0.05). In Exp. 2, piglets from STALL group also had higher BW (P < 0.05) and average daily gain (P < 0.05) at the end of lactation. During lactation, PEN gilts lost more BF than STALL gilts (P < 0.001). Gilts that are loose-housed and slightly overfed in pens during gestation may be more stressed when housed in farrowing stalls than those that have been kept in stalls during gestation, thus compromising their offspring thermoregulatory capacity and growth. For the second study, the aim was to develop a vitality scoring method based on piglet behavior and relate it to piglet growth and survival. From 21 sows, 287 piglets were used. After farrowing (day 0), piglets were weighed and tested for 4 behavioural parameters in a circular enclosure (55 cm diameter): movement capacity (M), udder stimulation (U), number of completed circles around the enclosure (N), and screaming (S). Piglets were weighed again on day 1, 2, 3 and 17. Piglet RT was recorded on day 0, 1, 2 and 3. Sow’s farrowing information was recorded. Multiple regression analyses for survival and BW gain at weaning as dependent variables was performed. Piglet BW gain at weaning was influenced by BW at birth (P < 0.001), sow parity (P = 0.024), total number of piglets born alive per sow (P < 0.001), and the sum of U and N parameters (UN; P = 0.023). Piglet survival during lactation was influenced by BW at birth (P = 0.015), UN parameter (P = 0.026), and RT on day 3 (P = 0.085). The sum of U and N parameters, in combination with BW at birth and information of the sow might be useful to predict piglet growth and survival during lactation, thus becoming a useful tool to improve piglet management during the first days of lactation. In conclusion, UN parameter seems to be an easy and useful way to assess piglet vitality for both scientific and commercial purposes. The third study focused on early management towards newborn piglets and its effect on piglet’s growth and survival. For the experiment, 39 primiparous sows and their litters (507 piglets) and 100 multiparous sows and their litters (1375 piglets) were used. Piglets were classified according to their BW at birth: SP, piglets born weighing 1.30 kg or less; and BP, piglets born weighing more than 1.30 kg of BW. Litters were allocated to one of the 4 treatments: control group (CON); split nursing of the BP piglets of the litter for 2 h allowing SP piglets free access to teats (SPLIT); orally supplementation with 15 ml of sow colostrum to the SP piglets of the litter (COL); and orally supplementation with 3 ml of an energetic product (Calostrene®) to the SP of the litter (EN). Cross-fostering was performed at a minimum level, fixing litters at 12 piglets (all the litters had 4 or 5 SP piglets). Piglets were weighed again on day 1 and 18 post-partum. Mortality was recorded. For primiparous sows oral supplementation with COL enhanced SP BW at day 1 compared to CON, SPLIT, and EN (P = 0.020, P = 0.022, and P = 0.046, respectively). However no differences were observed at day 18. For multiparous sows, no differences among treatment groups were observed for SP BW at day 1 and at day 18. Although there were no differences between gilts and multiparous sows for SP birth weight, gilt’s SP had higher BW at day 1 than sows’ SP (P = 0.020). Despite its effect on SP piglets’ BW at day 1, COL did not reduced pre-weaning mortality within gilt’s litters or within multiparous sows. Colostrum supplementation of low birth weight piglets enhanced their colostrum intake improving weight gain in piglets born from gilts. But it did not affect piglet’s weaning BW or pre-weaning mortality. The fourth experiment studied the effect of oral supplementation of piglets born weighing 1.35 kg or less (SP) (CON: control group; COL: 15 ml of sow colostrum fed within 4 h after birth), and the effect of cross-fostering 24 h after farrowing on litter performance (HL: litters fixed at 12 piglets, with less than 50% of the piglets being SP, aiming to as minimum movements of piglets as possible; LL: litter fixed with most of the piglets being SP) on litter performance. The combination of the 2 management strategies described above resulted in a 2 x 2 factorial model. Forty six litters were used. Litters were allocated to 1 of the 4 treatments: CON-HL, CON-LL, COL-HL, COL-LL. Piglets were weighed on day 1 and 19 post-partum. Mortality was recorded. On day 4 post-partum, a 2 ml blood sample was obtained from 79 SP piglets born from multiparous sows included in the experiment. To obtain a negative control group, blood samples were obtained on day 4 post-partum from 8 extra SP piglets that were separated from their mothers at birth and bottle fed with milk replacement for 12 h. LL sows had lower within litter CV of BW at day 1 than HL sows (16.2 vs. 21.9 ± 0.91%, P = 0.003) but they did not differ for litter CV of BW at day 19 (23.2 vs. 23.4 ± 1.72%; P > 0.10). At day 19, HL sows had lower number of dead piglets per litter than LL sows (0.80 vs. 1.69 ± 0.307; P = 0.022) and COL-HL sows had lower number of dead piglets per litter than CON-HL (0.47 vs. 1.14 ± 0.160; P = 0.062). Cross-fostering SP at the same litter did not prevent from increasing litter’s CV of BW at weaning. Piglets from COL group had higher IgG concentration than piglets from CON group (P = 0.001). While piglets from the negative control group had lower IgG concentration than COL and CON groups (5.4 ± 2.32 mg/ml vs. 30.6 ± 1.58 mg/ml and 21.5 ± 0.95 mg/ml. respectively; P < 0.001 in both cases). Allocating small piglets to the same litter through cross-fostering had a negative effect on mortality and did not improve litter CV of BW at weaning. Colostrum supplementation of SP piglets improves immune status at day 4. Besides, in non homogenized litters, coslostrum supplementation of SP piglets might be a good management strategy to improve litter performance.

Clinical studies have demonstrated an arousal deficit in infants suffering Obstructive Sleep Apnoea (OSA), and that treatment to alleviate the symptoms of OSA appears to reverse the deficit in arousability. Some sudden infant deaths are thought to be contingent upon such an arousal deficit. This research utilised young piglets during early postnatal development, and exposed them to intermittent hypercapnic hypoxia (IHH) as a model of clinical respiratory diseases. Arousal responses of control animals were compared to the animals exposed to IHH. Comparisons were also made between successive exposures on the first and the fourth consecutive days of IHH. Time to arouse after the onset of the respiratory stimulus, and frequency of arousals during recovery, demonstrated that arousal deficits arose after successive exposures and that these were further exacerbated on the fourth study day. After an overnight recovery period, the arousal deficit was apparently dormant, and only triggered by HH exposure. These studies confirm that both acute and chronic deficits can be induced on a background of otherwise normal postnatal development, suggesting that deficits observed in the clinical setting may be a secondary phenomenon.

Master of Science (Medicine)
Clinical studies have demonstrated an arousal deficit in infants suffering Obstructive Sleep Apnoea (OSA), and that treatment to alleviate the symptoms of OSA appears to reverse the deficit in arousability. Some sudden infant deaths are thought to be contingent upon such an arousal deficit. This research utilised young piglets during early postnatal development, and exposed them to intermittent hypercapnic hypoxia (IHH) as a model of clinical respiratory diseases. Arousal responses of control animals were compared to the animals exposed to IHH. Comparisons were also made between successive exposures on the first and the fourth consecutive days of IHH. Time to arouse after the onset of the respiratory stimulus, and frequency of arousals during recovery, demonstrated that arousal deficits arose after successive exposures and that these were further exacerbated on the fourth study day. After an overnight recovery period, the arousal deficit was apparently dormant, and only triggered by HH exposure. These studies confirm that both acute and chronic deficits can be induced on a background of otherwise normal postnatal development, suggesting that deficits observed in the clinical setting may be a secondary phenomenon.

This thesis reports five studies that may contribute to understand how weaning affects the immune and intestinal microbiota maturation of the piglet and proposes some possible nutritional strategies to attenuate its negative effects. The first study showed that weaning is associated in Payer’s patches with the activation of MHC response against class I antigens and that related to the stimulation to IFN-γ and showed, for the first time, that their blood at weaning remains dominated by immature blood cells. In the second study we tested if the use of a live vaccine against a conditionally but also genetically based intestinal disease, like PWD, could have an impact on the growth performance of pigs and their intestinal microbiota and if it could provide a model to test the response to nutritional strategies under conditions of an immune and intestinal stimulation for animals susceptible to ETEC type. In this study, we demonstrated how a vaccinal strain of F4/F18 E. coli can affect the gut microbial composition of piglets, regardless of their genetic susceptibility to ETEC infection. In the third study we evidenced how a nucleotide supplementation can favor the proliferation of jejunal Peyer patches and anticipate the maturation of the fecal microbiota. In the fourth study we reported how xylanase can favor the proliferation of Lactobacillus reuteri. Finally, we showed some first results on the muscles fiber development in fast- and slow-growing suckling pigs and the relationship with the intestinal microbiota. Taken together, the results presented in this thesis provide new insight about the interplay between the host-genetics, gut microbial composition, and host physiological status. Furthermore, it provides confirmation that the use of known genetic markers for ETEC F4 and F18 could represent a potential tool to stratify the animals in the trials both in healthy or challenge-based protocols.

Summary: Worldwide the swine industries are under pressure to reduce the use of antibiotics while maintaining animal health and performance. In 2006 all the AGP (antibiotic growth promoters) and some feed additives with growth promoting activities were banned (Cu, Zn). Since the first restrictive measures were taken, and due to the beginning of the negative consequences of the ban, numerous efforts have been done to find alternatives or replacement strategies to maintain pig growth performance and controlling enteric bacterial diseases. Therefore, the following studies aimed to find ways to control additive efficacy with due consideration to animal welfare and consumers requirements. The main objective of this thesis was to improve our knowledge on the properties of new additives as feeding strategy and oral vaccination to improve general and gut health in young pigs with the aim to substitute antibiotics growth promoters. To achieve these objectives, three different trials were designed to study different strategies to improve the gut health of the post-weaning piglets. I) Evaluation of the immune response against ovalbumin (OVA) in pigs orally vaccinated with OVA in tablets containing carboxymethyl high amylose starch (CM-HAS), flagellin and sow’s milk. This trial was designed with the aim to determine the effects of a new delivery system designed for oral vaccination or delivery of bioactive molecule in the gut. The trial was also designed to evaluate the potential of the sow’s milk to modulate the systemic as well as local immune response against the antigen ovalbumin incorporated in the vaccine. Sixteen piglets of 28 days (d) of age were divided into 4 groups of 4 animals each. The first group was vaccinated with compressed tablets containing only ovalbumin (OVA); the second group was immunized with tablets containing ovalbumin and the B subunit of the flagellin from Salmonella enterica Typhimurium (OVA-FLA); the 3rd and 4th groups were immunized with tablets containing ovalbumin pre-incubated in sow milk with or without flagellin, respectively (OVA-LT or OVA-LT-FLA). The oral vaccination was performed in two periods of three days; the 1st period being from day 28 to day 30 of age (D1-D3 of the trial) and the 2nd from 42 d to 45 d of age ( D14-D16). Blood samples were collected at days 1, 14, 21, 28 and 42 of the trial to determine, by ELISA, serum antibody titre against OVA. Feces samples were also collected before the first immunization and intestinal content from the ileum was collected at slaughtering to evaluate level of IgA anti-OVA by ELISA. All the animals were euthanized 42 days post-immunization to collect blood, mesenteric lymph nodes (MLN) and ileum content. The immune cells were isolated from the MLN and from blood and cultured with OVA to evaluate the lymphocyte proliferative response by flow cytometry (CFSE cell proliferation kit) and production of the main cytokine produced in adaptative immune response such as Interleukine-2 (IL-2) , IL-4, IL-10 and interferon-gamma (IFN-γ). Experimental animal studies have indicated that oral administration of antigens targets the systemic T cell compartment, diminishes cell-mediated immune responses, and induces tolerance. This phenomenon might lead to the induction of cytokines such as Transforming Growth Factor beta (TGF–β) and IL-10, and consequently enhance antigen-specific antibodies such as IgA and IgG. While the humoral immune response is critical in the control of some mucosal pathogens, those effects might be inappropriate on other mucosal pathogens where cell mediated immune responses may play a larger role. II) Milk rice in piglet nutrition: benefits or not? Rice milk has been shown to contain a high sugar level and antioxidants such as Ɣ-Oryzanol. For this reason the effects on growth performance and health status of piglets have been studied on 36 litters from (Landrace x LargeWhite) x Penerland sows. At 10 days after birth 18 litters were supplemented with rice milk (T) until weaning while the others 18 received creep feed (C). At 21 days a total of 288 piglets were weaned. Half from each group (72 piglets) were randomly assigned to either control (C) or treated (T), so there were four experimental piglet groups: C-C, C-T, T-C and T-T. All the animals received a pre-starter (0-14 d post weaning) and a starter (14-42 d pw) diets. Piglets from C-T and T-T groups were also supplemented with rice milk from weaning to 14 days pw. Piglets of T-C group had significantly higher weight at 42 d pw (P<0.01), an higher average daily gain (ADG) and dry matter feed intake (DMFI) (P< 0.01). Rice milk supplementation had no influence in glucose, urea, total protein and lysozyme. Reactive oxygen metabolites (ROMs) levels resulted lower in T-T piglets than C-C and C-T groups at 14 d-post w. (P<0.05). Total antioxidant capacity was higher in C-C and C-T than TC piglets at 14 d after weaning (P<0.05). The data from this trial suggest that rice milk was associated with greater post weaning growth and health status when supplementation was given only during the nursing period. III) Effects of plant polyphenols and mannan oligosaccharide on growth performance, antioxidant defense system and gut health in Escherichia coli Challenged piglets Objective of the current study was to evaluate the effects of plant polyphenols (PP) and/or, mannan oligosaccharide (MOS) on growth performance, plasma antioxidant capacity and health in E. Coli-challenged weaned piglets. Ninety-six piglets (7.43 + 0.89 kg L.W., 21 d age) were randomly allotted into 4 dietary treatments: control (basal diet), 0.1% PP, 0.1 % MOS or PP+MOS in a 5 weeks study. At 21 and 25 d on trial half piglets of each group were orally inoculated with 4 ml of E.coli (1×109 cfu/ml) and half with the same amount of saline water. No difference was observed in growth. Plasma urea was markedly increased in PP+MOS group compared to PP group (P< 0.05), and lysozyme content was significantly decreased in PP+MOS group compared to groups on d 7 (P< 0.05). PP+MOS dietary supplementation decreased intestinal lipase and trypsin compared to PP on d 21 (P< 0.05). Plasma malondialdehyde content (MAD) increased, while plasma total antioxidant capacity (TAOC) and catalase (CAT) activities decreased in piglets 6 days after infection. Challenged piglets fed PP and those fed MOS showed higher TAOC than challenged piglets fed PP in combination with MOS. CAT activity resulted higher in challenged piglets fed diet supplemented with PP or PP+MOS than control or MOS at d 13 after infection (P< 0.05). The results showed that dietary PP or MOS had the potential to improve enhance systemic antioxidant capacity. However no synergic effect was observed when PP and MOS were combined. General conclusions During the weaning period, several factors affecting the welfare and health of piglets with a consequently effect on the productive performance of the animals. One of the key factors for high growth performance is the maintenance of a healthy gut. The presence of a balanced enteric microflora which may protect the piglets from weaning common bacterial infections, has a general beneficial effect on the health of the animal. What we tried to demonstrate with this thesis is that we are running the correct way to find alternatives substances to protect the gut health of our piglets, but more research will be needed to understand different techniques such the oral vaccination of the animals.

Post-weaning is the most crucial period in pig management. Associated with weaning are marked changes to the histology and biochemistry of the gut which cause decreased digestive and absorptive capacity and contribute to post-weaning diarrhoea. In last years, the interest in developing management and feeding strategies to stimulate gut development and health in newly-weaned pigs was increasing. In order to increase general health in post-weaning piglets and be alternative to in-feeding antibiotic, three trials were created in this thesis to determine the utilizations of some functional foods which have been widely used to improve growth performance while minimizing the use of antibiotics and rather expensive feed ingredients in weaned piglets. We utilized essential oils (Thymol and Cinnamaldehyde, EO) and/or enzymes (Xylanase and β-glucanase, XB) in the first 2 trials. The first trial mainly focused on the effects of those additives on general parameters such as performance and digestibility of weaned piglets. To investigate the possible protective effects of EO and/or XB on health status in weaned piglets, we created a model of challenge using Escherichia coli in the second trial. After first two investigations, we intended to enlarge the categories of functional foods and determine the effects on regulation of systemic inflammatory reaction and, in addition, we supposed that initial body weight might also influence the regulation. Therefore, the third trial was desined to determine the effects of dietary cocktail (bovine colostrums, cranberry extract, encapsulated essential oil, yeast-derived products, the probiotic Pediococcus acidilactici MA18/5M, vitamins A, D, E and B complex, seleno-methionine) and body weight on inflammatory cytokines and time responses under Lipopolysaccharides challenge in early weaned piglets. In the first trial, a total of 192 weaned piglets (Stambo HBI Dalland 40, 24 d) with an average initial body weight of 8.10 kg were allocated according to body weight into 4 experimental treatments (12 replicates per treatment with 4 piglets per replicate). Each group was fed the basal diet alone or supplemented with either essential oils or enzymes, or their combination. There was no effect of essential oils and/or enzymes supplementation on the growth performance of piglets. However, the combination of essential oils and enzymes decreased feed conversion ratio during the last week. Although the fecal digestibilities of all the piglets were increased from d 21 to 35 (P < 0.001), no effect of essential oils or enzymes or the combination on the fecal digestibility was observed. All the additives significantly decreased counts of Coliforms at 42 days of the trial (P < 0.001). Dietary enzymes improved gut morphology by decreasing crypt depth, increasing villus:crypt ratio and reducing the number of macrophages (P < 0.001). Supplementation of essential oils and the combination with enzymes also improved gut morphology by decreasing crypt depth (P = 0.065; P < 0.001), and decreasing the number of lymphatic follicles (P = 0.002; P < 0.001) and macrophages (P < 0.001). No effect of additives on mRNA expression of inflammatory cytokines was observed in ileal mucosa. Results showed that diet supplementation with EO and/or XB had positive effects on intestinal bacterial counts and gut morphology, although there was no significant diet effect on grow performance or digestibility. In the second trial, 192 weaned piglets (Stambo HBI Dalland 40, 8.64 kg) were allocated according to body weight into eight experimental treatments (6 replicates per treatment with 4 piglets per replicate). The treatments were in a factorial arrangement: 1) dietary treatments [a weaned piglet control diet (CTR), CTR + 0.05 g/kg essential oils (EO), CTR + 0.1 g/kg enzymes (XB), and CTR + 0.05 g/kg EO + 0.1 g/kg XB] and 2) with or without an E. coli challenge. On d 8, half of piglets in each dietary group were challenged with E. coli. E. coli challenge significantly impaired growth performance, induced severe diarrhea, increased populations of E. coli, Clostridia and Coliforms, depressed antioxidant activities, damaged gut morphology and promoted TLR-4 and TNF-α mRNA expression in ileal mucosa (P < 0.05). In the E. coli challenge group, dietary enzymes or combinated with essential oils improved feed efficiency compared with control treatment during the last week (P = 0.025; P = 0.020). The Coliforms populations in the cecum of challenged piglets fed combination of essential oils and enzymes were lower than control treatment (P < 0.001). In the E. coli challenge group, supplemented essential oils and/or enzymes improved gut morphology by increasing villus height and villus:crypt ratio and decreasing crypt depth (P < 0.001). The positive effects on intestinal bacterial counts and gut morphology suggests that supplementation of EO and/or XB might improve the protective capacity against pathogenic bacteria when piglets were submitted to a bacterial challenge. In the third study, a total of 256 Yorkshire × Landrace weaned piglets (20 ± 1 d) were allocated into eight experimental treatments (8 replicates per treatment with 4 piglets per replicate). The treatments were in a factorial arrangement: 1) dietary treatments: a basal weaning diet added [spray-dried plasma protein (PP) (CTR), PP + antibiotic (ATB), PP + dietary cocktail (DC), or bovine colostrum + the dietary cocktail (BC+DC)] and 2) low weight (LW) or high weight (HW). At 37 d of age, 2 piglets in each pen were injected with LPS. Stimulations of LPS and PMA in PBMCs of piglets significantly induced TNF-α, IL-8 and IL-10 (P < 0.05). There was no diet effect on the concentrations of TNF-α, IL-8 and IL-10 in PBMCs of piglets (P > 0.05). Piglets had low weight tended to increase the concentration of IL-8 (P = 0.106) and IL-10 (P = 0.098) in the PBMCs stimulated by LPS 0.5µg/ml LPS and the concentration of IL-10 (P = 0.097) in PMA stimulated PMBC compared with high weight animals. Infection with LPS increased (P < 0.001) serum concentrations of all the cytokines four hours post inoculation, and animals recovered to basal levels at 18 h after challenge. No significant diet effect was found in the serum concentrations of cytokines (P > 0.05). At 4 h after challenge, low weight piglets had partially greater serum concentrations of TNF-α (P = 0.046), IL-6 (P = 0.158), IL-8 (P = 0.179) and IL-10 (P = 0.185) than high weight animals. Dietary cocktail or combined with bovine colostrum may replace plasma protein and antibiotics and weight difference may influence the production of inflammatory cytokines after infected by LPS. In conclusion, we observed that supplementation of functional foods as essential oils and enzymes might strengthen protective capacity of weaned piglets against pathogenic bacteria by decreasing negative intestinal bacterial counts and improving gut morphology. Dietary cocktail or combined with bovine colostrums, at the amount used in this work, may replace plasma protein and antibiotics. Besides, weight difference may influence the production of inflammatory cytokines after infected by LPS.

The female mammal makes an enormous metabolic investment in the early development of her offspring and this continues until the offspring is independent of its mother at weaning. Mammary secretion of colostrum and then milk requires a high proportion of ingested nutrients from the maternal diet and represents a continuation of metabolite partitioning for the growth and development of the young in-utero. Lactation represents the most energetically demanding process of the reproductive cycle. This thesis reviews current knowledge of the composition of porcine colostrum and mature milk, focusing on compositional differences that may help account for the poorer weaning performance of gilt litters in comparison to performance of litters of more experienced sows.

FundaÃÃo de Amparo à Pesquisa do Estado do CearÃ
The objective was to evaluate the calcium anacardate as an alternative growth promoter in feed for piglets at nursery phase, on performance, occurrence of diarrhea, serum parameters, intestinal morphology and pH of the gastrointestinal contents. A total of 60 piglets were used, weaned at 21 days of age, distributed among 5 treatments: negative control (CN) - feed without growth promoter inclusion; positive control (CP) - feed with antibiotic growth promoter (AGP); AC 0.4% - feed with 0.4% calcium anacardate; AC 0.8% - feed with 0.8% calcium anacardate; AC 1.2% - feed with 1.2% calcium anacardate, with 6 replicates per treatment, considering the pen containing 2 piglets as experimental unit. The experiment lasted 22 days, divided in period I (21-32 days) and period II (21-42 days). It was observed that the performance of piglets fed with calcium anacardate didnât differ from those fed with AGP. The inclusion of calcium anacardate from 0.8% in the feed resulted in serum globulin levels similar to those animals receiving the feed with AGP. Although the occurrence of diarrhea was lower in animals that received AGP, the villus height (VH) and villus height-to-crypt depth ratio (V/C) in the animals who received calcium anacardate in the diet was similar to the treatment with AGP. Calcium anacardate can act as a replacement for AGP in diets for piglets at nursery phase, considering that from the inclusion of 0.8% showed benefits in intestinal morphology and serum parameters of animals.
Objetivou-se avaliar os efeitos da utilizaÃÃo do anacardato de cÃlcio como promotor de crescimento alternativo em raÃÃes para leitÃes na fase de creche, quanto ao desempenho, ocorrÃncia de diarreia, parÃmetros sanguÃneos, morfologia intestinal e pH dos conteÃdos gastrintestinais. Foram utilizados 60 leitÃes desmamados aos 21 dias de idade, distribuÃdos entre 5 tratamentos : controle negativo (CN) â raÃÃo sem inclusÃo de promotor de crescimento; controle positivo (CP) â raÃÃo com inclusÃo de antibiÃtico promotor de crescimento (APC); AC 0,4% - raÃÃo com inclusÃo de 0,4% de anacardato de cÃlcio; AC 0,8% - raÃÃo com inclusÃo de 0,8% de anacardato de cÃlcio; AC 1,2% - raÃÃo com inclusÃo de 1,2% de anacardato de cÃlcio, com 6 repetiÃÃes por tratamento, considerando a gaiola contendo 2 animais como unidade experimental. O perÃodo experimental foi de 22 dias, sendo divididos em perÃodo I (21 a 32 dias) e perÃodo II (21 a 42 dias). Observou-se que o desempenho dos leitÃes alimentados com raÃÃo contendo anacardato de cÃlcio nÃo diferiu daqueles alimentados com raÃÃo contendo APC. A inclusÃo de anacardato de cÃlcio a partir de 0,8% na raÃÃo resultou em valores de globulina sÃrica semelhantes aos dos animais que receberam APC na raÃÃo. Embora a ocorrÃncia de diarreia tenha sido menor nos animais que receberam APC, os valores de altura de vilosidade (AV) e relaÃÃo altura de vilosidade / profundidade de cripta (AV/PC) nos animais que receberam anacardato de cÃlcio na raÃÃo foram similares ao tratamento com APC. O anacardato de cÃlcio pode atuar como um substituto aos APC em raÃÃes para leitÃes na fase de creche, considerando que a partir da inclusÃo de 0,8% houve benefÃcios na morfologia intestinal e nos parÃmetros sÃricos dos animais.

Survival and growth of the piglet is determined by its ability to suckle rapidly after birth, which can be influenced by sow udder morphology. The initial aims of this research were to define a methodology to describe udder morphology (1), to study the sources of variation in the morphology (2) and its relationship with piglet teat preferences (3). A further aim was to assess colostrum quality (IgG) using a quick on-farm method (4), and the final objective was to estimate the heritability (h2) of udder morphology and colostrum traits (5). A methodology to describe a sow udder was developed from review of udder morphology literature and a pilot experiment assessed effects of sow posture, laterality and day on six udder traits, with good repeatability. Methodology was then applied and showed that sows parity number, breed, and teat pair position (anterior, middle, posterior) were significant sources of variation in udder traits. A study on newborn piglet suckling behaviour showed that piglet characteristics such as vitality score and birth weight did not affect teat preference or the latency from birth to first suckling. The majority of siblings suckled for the first time from a previously used teat, mostly located in the posterior part of the udder, though late born piglets preferred teats located in the anterior part. The evaluation of Brix refractometer percentage to assess IgG showed a positive correlation with laboratory Radial immunodiffusion results. Therefore this tool was adopted to investigate the genetic potential of colostrum IgG concentration. All udder morphology and colostrum traits measured in this study were moderate to highly hereditable, with some important correlations with reproductive and productive traits. These udder traits should be included in the breeding goal and weighed appropriately with other important traits in the breeding objectives to enhance optimal genetic progress.