Para ser competitivo atualmente, o sistema intensivo de produção de suínos deve estar pautado na eficiência. A fim de obter esta eficiência produtiva, o avanço genético das ultimas décadas buscou por fêmeas suínas cada vez mais prolíficas. A prolificidade contudo, veio acompanhada por uma queda no consumo voluntário de alimento por parte das fêmeas, bem como um aumento na produção de leite, e no número de leitões nascidos; o aumento da leitegada, levou a uma redução do peso ao nascimento e um aumento da heterogeneidade entre os leitões. Como forma de contornar o problema, são oferecidas aos leitões dietas formuladas com ingredientes de alto valor biológico a partir dos sete dias de vida, procurando suprir a demanda nutricional do animal durante o período de amamentação e preparar seu sistema digestório para o desmame. Contudo, grande parte das dietas formuladas para os leitões neonatos são oferecidas aos animais em sua forma sólida. Neste projeto, avaliamos os efeitos sobre a performance de leitões neonatos e da performance reprodutiva da fêmea suína do oferecimento de uma dieta líquida para os leitões neonatos, dieta esta que foi disponibilizada aos animais através de um sistema automatizado que realizou a mistura do alimento em sua forma sólida com a água. Para tais avaliações, os leitões ao nascer foram alocados em três grupos distintos, recebendo a dieta em sua forma líquida, em sua forma sólida ou então apenas o leite materno. Foram avaliadas variáveis zootécnicas relacionadas aos leitões, como peso, ganho diário de peso, consumo de ração, conversão alimentar, mortalidade pré-desmame; frequência de dias com diarreia nos leitões em fase de maternidade e creche. Foram eutanasiados leitões aos 14 e aos 28 dias de idade, para a realização do exame morfométrico da altura de vilosidade, profundidade de cripta e a relação entre a altura de vilosidade e profundidade de cripta nas porções do duodeno, jejuno e íleo. Avaliamos também o impacto do uso da dieta líquida sobre o catabolismo sofrido pela fêmea durante a lactação, através da aferição do peso e da espessura de toucinho desta fêmeas durante o período lactacional e também a duração do intervalo desmame estro e a duração do estro subsequente ao desmame. Não verificamos contudo um melhor desempenho zootécnico dos leitões nos períodos de maternidade e creche, tão pouco uma alteração favorável quanto a frequência de dias com diarreia nas duas fases em relação aos leitões que não consumiram nenhum tipo de suplementação. Quanto aos parâmetros morfométricos do intestino delgado, apenas aos 28 dias de idade os leitões que receberam a dieta líquida apresentaram maiores alturas de vilosidades no íleo em relação aos leitões que consumiram a dieta sólida e os animais do grupo controle apresentaram menores profundidades de cripta no mesmo seguimento e idade quando comparados aos demais animais. Contudo, estas alterações não foram o suficiente para garantir diferenças na relação altura de vilosidade:profundidade de cripta. E ainda, a suplementação independente de sua forma não reduziu o catabolismo sofrido pela fêmea suína durante a lactação / To be competitive today, intensive pig production system must be founded on efficiency. In order to obtain this production efficiency, genetic progress of recent decades sought for sows increasingly prolificity. Prolificity however, was accompanied by a decrease in voluntary feed intake by the sow, an increase in milk yield, and the number of piglets born; increased litter led to a reduction in birth weight and increased heterogeneity among piglets. In order to solve this problem, are offered to piglets diets formulated with high biological value ingredients starting at seven days of life, trying to meet the nutritional demand of the animal during the breastfeeding period and prepare digestive system for weaning. However, most diets formulated for newborns piglets are offered in its solid form. In this project, we evaluated the effects on performance of newborn piglets and reproductive performance of swine female offering a liquid diet for the newborn piglets, which was made available to the animals through an automated system that held the mixture of solid feed with water. For such evaluations, the piglets were divided into three groups, receiving the diet in liquid form ,in its solid form or only breast milk. Husbandry variables related to the piglets were evaluated, such as weight, daily gain, feed intake, feed conversion, pre-weaning mortality; frequency of days with diarrhea in piglets in maternity and nursery. Piglets were euthanized at 14 and 28 days for morphometric examination of villus height, crypt depth and the ratio of villus height and crypt depth in the portions of the duodenum, jejunum and ileum. We also evaluated the impact of the use of liquid diet on the catabolism suffered by the sow during lactation, by measuring the weight and backfat thickness during the lactation period and also the duration of weaning to estrus interval and duration of the subsequent estrus. We not checked a better growth performance of piglets during periods of maternity and nursery, nor a favorable change for the frequency of days with diarrhea in this two phases. As for the morphometric parameters of the small intestine, only 28 days old piglets that received liquid diet showed greater heights of villi in the ileum for piglets that consumed the solid diet and the control group showed lower crypt depth in the same tracking and age when compared to other animals. However, these changes were not enough to warrant differences in villus height:crypt depth. And yet, the independent supplementation of its form not reduced catabolism suffered by female swine during lactation

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Surgical castration of young male piglets is an extremely common husbandry procedure in the United States swine industry, with nearly 100% of males castrated. The procedure is performed primarily to prevent the occurrence of boar taint in the meat and to reduce aggression as the animals age. No research has investigated the impact of surgical castration on the long-term mood states – also known as the affective state – of piglets, but it has been proven to cause both acute and chronic pain that can last up to 4 days, modify piglet behavior, and reduce weight gain. Because of this, feasible approaches for pain alleviation are needed. A hinderance to this is that currently no analgesics are approved for piglets. In addition, we need validated, practical methods to recognize pain in piglets in order to help researchers, veterinarians, and caretakers to identify the need for analgesics. One useful tool for this could be the Piglet Grimace Scale, which has previously been validated in this context, but is not widely applied. The current lack of analgesic use during castration may be cause for concern for consumers, however little is known about the public's knowledge on the industry's practices. Therefore, the thesis' objectives are to (1) assess the impact of surgical castration on pain and affective states, (2) determine people's ability to recognize pain expression after surgical castration, and (3) get insights into public perception of swine industry practices. In Chapter 3, we assessed the impact of surgical castration and practical pain alleviation methods during and after castration on piglets' short and long-term affective states and activity levels. Piglets were surgically castrated, castrated with analgesics, or sham-handled at 3 days of age. Data on piglets' activity (using accelerometers), tails (affective states), and grimaces (pain expression) were collected for 1, 6, and 24 hours after castration treatments while piglets were in their home pens. An attention bias test was then performed in week 1 and 12 to assess anxiety (an affective state). Home pen activity after castration treatments suggested that there was a positive impact of using analgesics. The piglets' behavior (eating) and activity during the attention bias test at week 1 suggest a negative impact of castration on affective states. The differences observed in week 1 were no longer found in week 12, suggesting that any impact of surgical castration at 3 days of age on affective states are no longer detectable at 12 weeks of age. In Chapter 4, through an online survey we investigated the validity and reliability of Piglet Grimace Scale ratings applied by swine industry professionals and the general public, to assess its potential utility in non-research settings. The survey contained a training, followed by 9 piglet images showing facial expressions immediately after castration or sham-handling. Both response groups were able to recognize pain in castrated piglets. However, both response groups overestimated pain experience compared to trained experts, suggesting more training may be necessary. Nevertheless, overall, the scale can be widely applied by veterinarians, industry professionals and even members of the public. In Chapter 5, a survey provided initial insights into public knowledge and perceptions on castration and analgesia use and compared this to industry stakeholders. The results show that knowledge on industry practices was especially lacking for public respondents, but also for a minority of industry respondents, indicating opportunities for education and further research on the topic. / Master of Science / Surgical castration is performed on nearly every male piglet in the United States swine industry. Males are castrated to prevent the occurrence of boar taint and to reduce aggression. Boar taint is the unpleasant odor produced by the skatole and androsterone in the fat when the meat is prepared. It is unclear how this practice impacts piglet's long-term mood states (affective states), but we do know it causes pain, changes in behavior, and reduced productivity. Thus, we need feasible approaches for pain relief. However, there are currently no pain relievers approved for piglets. In addition, we need validated, practical methods to quantify pain in piglets in order to identify the need for pain relief. One useful tool is the Piglet Grimace Scale, which is validated but is not widely applied. The current lack of pain relief use during castration may concern consumers, yet no data is collected on this. Therefore, the thesis' objectives are to (1) assess the impact of surgical castration on pain and affective states, (2) determine people's ability to recognize pain expression after surgical castration, and (3) get insights into public perception of swine industry practices. In Chapter 3, we assessed the impact of surgical castration and practical pain alleviation methods during and after castration on piglets' short and long-term affective states and activity levels. Piglets were surgically castrated, castrated with analgesics, or sham-handled at 3 days of age. Home pen activity after castration treatments showed a positive impact of using analgesics. The piglets' behavior and activity during an attention bias test at week 1 suggest that piglets were experiencing a negative emotional state after castration. The differences seen in week 1 were no longer found in week 12. This suggests that any potential impact of surgical castration on affective states are no longer detectable at 12 weeks of age. In Chapter 4, an online survey was used to investigate the Piglet Grimace Scale ratings applied by swine industry professionals and the general public. After training, respondents scored 9 images showing facial expressions of piglets after castration or sham-handling. Both public and industry people were able to recognize pain in castrated piglets. However, both response groups overestimated the pain experience compared to trained experts, suggesting more training may be necessary. Nevertheless, overall findings suggest that the scale can be widely applied. In Chapter 5, a survey provided insights into public knowledge and perceptions on castration and pain relief use in the industry, and compared this to industry stakeholders. The results showed that knowledge on industry practices was especially lacking for public respondents, but also for a minority of industry respondents, indicating opportunities for education and further research on the topic.

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 objective of this research was to investigate the behavioural, physiological and immunological effects of routine surgical procedures in neonatal swine in order to provide producers with science-based recommendations. In the first experiment, low- or average-birth-weight piglets that were tail docked and ear notched at 1 or 3 days of age showed subtle differences resulting from age at processing. However, low-birth-weight male piglets had the lowest attendance during nursing bouts and spent the greatest amount of time lying alone. Vocalization data suggests that ABW piglets may be less reactive to the procedures on d 1. Overall, the decreased vitality and reduced survivability of low-birth-weight piglets suggests that delaying processing until day 3 for these piglets may be preferable. In the second experiment, the effects of docked tail length and nursery stocking density on tail-biting behaviour, skin lesions and rectal prolapses were investigated. Long-tailed pigs (docked to 4.5 cm at birth) were most vulnerable to tail-biting, and housing at a moderate versus high nursery stocking density was not sufficient to reduce tail-biting. High nursery stocking density negatively impacted skin lesion scoring and growth performance for the majority of the grower-finisher period. Pigs from either nursery stocking density and docked tail length groups were equally likely to be affected by prolapsed rectal mucosa. Given the decreased survivability and significantly lighter weaning weight for low-birth-weight piglets compared to those of average-birth-weight, delaying processing of low-birth-weight piglets may be the most humane option. Further, until tail-biting is better understood and a more effective solution found, the routine docking of tails remains the optimal method for balancing a situation with enormous welfare-reducing potential. / Agriculture and Agri-Food Canada

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Made available in DSpace on 2017-07-10T17:48:24Z (GMT). No. of bitstreams: 1 Pryscilla Cenci de Barros.pdf: 261634 bytes, checksum: b86848d5ab9e125579adb6b4c23a23d7 (MD5) Previous issue date: 2010-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study to evaluate the effect od addition of amylase and protease, isolated or in combination on the digestibility of nutrients in diets for piglets in the nursery phase. It was used 16 piglets with initial weight of 8.04 kg were individually penned in metabolism cages. The experimental treatments consisted of four isoenergetic and isolisinic and differed only in addiction or not of enzymes: treatment 1 = control diet; treatment 2 = 0.06% of amylase; treatment 3 = 0.0125% of protease; treatment 4 = 0.06% of amylase and 0.0125% of protease. The experimental desing was completely randomized desing with four replications and two phases. No effect of the inclusion of amylase and protease, alone or combined, in the digestibility of dry matter, organic matter, crude protein, ash, starch and gross energy. it is concluded that supplementation with amylase and protease isolated or in combination in diets for piglets in the nursery phase did not result in improvement of digestibility coefficients of the variables, but when nalyzing the phases separately, the digestibility coefficients were higher in the phase 2 in all treatments / Objetivou-se com este estudo avaliar o efeito da adição das enzimas amilase e protease, isoladas ou combinadas, sobre a digestibilidade dos nutrientes de rações para leitões na fase de creche. Utilizaram-se 16 leitões machos castrados com peso vivo médio inicial de 8,04 quilos os quais foram alojados individualmente em gaiolas de metabolismo. Os tratamentos experimentais consistiram de quatro rações isoenergéticas e isolisínicas que diferiram apenas na adição ou não de enzimas: tratamento 1 = ração controle; tratamento 2 = 0,06% de amilase; tratamento 3 = 0,0125% de protease; tratamento 4 = 0,06% de amilase e 0,0125% de protease. O delineamento experimental utilizado foi o delineamento inteiramente casualizado, com duas fases e quatro repetições por fase. Não houve efeito da inclusão de amilase e protease, isoladas ou combinadas, nos coeficientes de digestibilidade da matéria seca, matéria orgânica, proteína bruta, matéria mineral, amido e energia bruta. Conclui-se que a suplementação com amilase e protease isoladas ou em combinação em rações para leitões na fase de creche não resultou em melhora dos coeficientes de digestibilidade das variáveis estudadas, porém ao analisar-se as fases separadamente, os coeficientes de digestibilidade foram superiores na fase 2 em todos os tratamentos

Dans le contexte de l'antibiorésistance, l'objet de ce doctorat vise à évaluer l'impact d'antibiotiques sur le microbiote intestinal de porcelets. La colistine et le ceftiofur, pour lesquels les résistances incluent essentiellement et respectivement mutations chromosomiques et gènes plasmidiques, ont été utilisés. La colistine a significativement réduit la population des entérobactéries, mais aucun E. coli résistant n'a été détecté. L'administration de ceftiofur a eu un impact limité sur les populations bactériennes composant l'écosystème digestif mais a conduit à une forte sélection et à la diffusion d'un gène plasmidique codant pour une bêta-lactamase à spectre étendu. Puis, dans le cadre de la réglementation visant à diminuer l'expérimentation animale, un modèle in vitro colique porcin, nommé PigutIVM, a été mis au point afin de simuler l'environnement digestif du porcelet et a permis de confirmer, in vitro, l'effet observé in vivo de la colistine sur le microbiote. Cet outil a ensuite été utilisé pour évaluer l'impact d'un probiotique, Saccharomyces cerevisiae, comme alternative aux antibiotiques. Le modèle PigutIVM devrait se positionner comme un outil de prédiction pertinent dans les domaines d'investigation aussi bien nutritionnels que pharmacologiques. / In the context of antibiotic resistance, the aim of the current PhD work is to assess the impact of antibiotics on intestinal microbiota of piglets. Two antibiotics i.e. colistin and ceftiofur, for which the main resistances include respectively chromosomal mutations and plasmid genes have been used. Colistin significantly reduced the population of Enterobacteriaceae, but there was no selection of resistant E. coli. The administration of ceftiofur had a limited impact on the bacterial populations that make up the digestive ecosystem but it led to strong selection and dissemination of a plasmid gene encoding an extended-spectrum beta-lactamase. Then, in the framework of regulations to reduce animal testing, an in vitro model of colonic pig named PigutIVM was developed in order to simulate the digestive environment of the piglet and then check the effect of colistin on the microbiota simulated in PigutIVM in vitro. Therefore both the approaches i.e. in vivo and in vitro were compared in order to check the effect of colistin on intestinal microbiota of piglets. This tool was then used to evaluate the impact of a probiotic i.e. Saccharomyces cerevisiae, as alternative to antibiotics. Therefore we assume that this PigutIVM model should be positioned as a relevant predictive tool in the fields of nutritional and pharmacological investigations.