The effects of increasing feed intake (1.8, 2.3, 2.8, and 3.3 kg/d) during late gestation of gilts on piglet birth weight and female reproductive performance were evaluated. A total of 977 gilts were fed a diet based on corn-soybean meal (3.29 Mcal ME per kg and 0.64% standardized ileal digestible lysine) from day 90 of gestation until farrowing. Gilts were weighed on days 90 and 112 of gestation, at farrowing and weaning. Born alive and stillborn piglets were weighed within 12 h of birth. Colostrum yield (CY), lactation feed intake, and litter growth rate were measured in a randomly selected subsample of 245 gilts. The data were analyzed using generalized linear mixed models. As expected, gains in body weight (BW) were different at day 112 (P < 0.001) with the greatest values observed in the 3.3 kg/d treatment. As feed intake increased during late gestation, BW, body condition score (BCS), backfat (BF), and Caliper unit also increased between day 112 and weaning (P < 0.001). No differences were found among treatments in total number of piglets born, mummified fetuses, sum of born alive and stillborn piglets, and within-litter birth weight CV (P > 0.05). Tendencies for quadratic effect of feed intake were observed for born alive piglets (P = 0.079), average birth weight of piglets (P = 0.083), and litter weight (P = 0.059). Gilts with lower feed intake during late gestation had reduced percentages of stillborn piglets than gilts with greater feed intakes. The CY decreased linearly (P < 0.05) as the feed intake was increased. No differences among treatments were found at weaning in individual piglet weight and litter weight, as well as in percentage of weaned piglets (P > 0.05). Lactation feed intake decreased as gestation feeding level increased (P < 0.05). No differences in the subsequent cycle were observed among treatments for farrowing rate, retention rate up to the next farrowing, number of total piglets born, born alive, stillborn piglets, and mummified fetuses (P > 0.05). In conclusion, increased feed intake from day 90 of gestation until farrowing resulted in increased maternal BW gain and stillborn rate, but reduced CY and lactation feed intake. A slight increase in birth weight was observed for the 2.3 kg/d treatment. Furthermore, litter growth and subsequent female reproductive performance were not affected by feed intake during late gestation.

The Infectious Bursal Disease (IBD) is a contagious viral disease that affects young chickens and may cause high morbidity and mortality. As the virus is very resistant to the environment, vaccination is required in case of high infection pressure. Due to variations in the virulence degree of the vaccines available to control IBD, this study aimed at evaluating the pathogenicity and immunogenicity of three types of vaccines. In total, 220 one-day-old specific pathogen free (SPF) chickens were immunized with recombinant, immune-complex and intermediate vaccines, or not vaccinated (55 birds per group) and challenged with IBD G11 strain on day 25. On days 25, 30, and 35, the Bursa of Fabricius (BF) were submitted to gross and histological examination, and serum samples were submitted to ELISA to determined anti-IBD antibody titers. On day 23, chickens were submitted to the test of hypersensitivity to phytohemagglutinin to evaluate the immunosuppressive effect of vaccines on the cell-mediated immunity. The results have indicated that the immune-complex vaccine induced the most severe BF lesions, whereas the recombinant vaccine preserved BF tissue and cell integrity. The three evaluated vaccines induced humoral immunity of similar intensity. The cellular reaction to phytohemagglutinin of the chickens immunized with recombinant and immune-complex vaccines was less severe compared with the unvaccinated chickens. In conclusion, these results indicate that the immune-complex vaccine was the most pathogenic and that all vaccines were effective in protecting SPF chickens against IBD.

<p>Para impedir a dispersão de microrganismos patogênicos ao longo da cadeia avícola medidas de biosseguridade são adotadas, sendo a desinfecção procedimento obrigatório e o composto químico cloreto de benzalcônio (quaternário de amônio) largamente usado para essa finalidade. Devido ao fato de que parte das criações brasileiras localizam-se em regiões com grande amplitude térmica, o mesmo ocorrendo entre as diferentes áreas e secções de matadouros-frigoríficos, executou-se este experimento para verificar a atividade desse desinfetante simulando condições de uso frente a 33 isolados de <italic>Salmonella</italic>Hadar. Pelo teste de suspensão observou-se a inativação bacteriana sob as variáveis concentração (100 e 200 ppm), temperatura (20 ± 2 ºC e 8 ± 2 ºC), carga de matéria orgânica (1 e 3 %) e tempos de contato (5, 10 e 20 minutos). Como resultados, a 20 ± 2 ºC todos os isolados foram inativados nas duas concentrações e cargas orgânicas após 5 minutos de contato. Sob temperatura de 8 ± 2 ºC o desinfetante teve sua atividade comprometida, tendo isolados bacterianos sobrevivido sob todas as variáveis de confronto (33,3% frente 100 ppm e 6,1% frente 200 ppm). Quanto menor a concentração do desinfetante e maior carga orgânica, maior o número de isolados viáveis. Conclui-se que, nas condições do experimento, o cloreto de benzalcônio foi capaz de inativar todos os isolados do sorovar de<italic>Salmonella</italic> confrontados, podendo ser empregado nos procedimentos de desinfecção. No entanto, a baixa temperatura ambiente é fator de limitação na indicação de seu uso.</p>

Resumo O objetivo deste trabalho foi predizer os indicadores de produção e determinar o seu potencial impacto econômico em um sistema de integração utilizando as redes neurais artificiais (RNA). Quarenta parâmetros zootécnicos e de produção de granjas de matrizes e de frango de corte, um incubatório e um abatedouro foram selecionados como variáveis. Os modelos de RNA foram estabelecidos para quatro variáveis de saída (“eclosão vendável”, “peso ao final da quinta semana”, “condenações parciais” e “condenações totais”) e foram analisados em relação ao coeficiente de determinação múltipla (R2), coeficiente de correlação (R), erro médio (E), erro quadrático médio (EQM) e raiz do erro quadrático médio (REQM). Os cenários produtivos foram simulados e os impactos foram estimados. Os modelos de RNA gerados foram adequados para simular diferentes cenários produtivos após o treinamento. Para “eclosão vendável”, o modelo de incubadora e o período de incubação aumentaram os ganhos financeiros. Para “peso ao final da quinta semana”, a linhagem também demonstrou influencia no retorno financeiro, o que não aconteceu com o peso ao final da primeira semana. O sexo do lote possui influência nas taxas de “condenação parcial”, ao contrário do peso do frango no primeiro dia. As taxas de mortalidade e o peso do frango apresentaram influência na “condenação total”, mas o sexo do lote e o tipo de pinto não tiverem influência.

The aim of this study was to predict production indicators and to determine their potential economic impact on a poultry integration system using artificial neural networks (ANN) models. Forty zootechnical and production parameters from broiler breeder farms, one hatchery, broiler production flocks, and one slaughterhouse were selected as variables. The ANN models were established for four output variables: “saleable hatching”, “weight at the end of week 5,” “partial condemnation,” and “total condemnation” and were analyzed in relation to the coefficient of multiple determination (R2), correlation coefficient (R), mean error (E), mean squared error (MSE), and root mean square error (RMSE). The production scenarios were simulated and the economic impacts were estimated. The ANN models were suitable for simulating production scenarios after validation. For “saleable hatching”, incubator and egg storage period are likely to increase the financial gains. For “weight at the end of the week 5” the lineage (A) is important to increase revenues. However, broiler weight at the end of the first week may not have a significant influence. Flock sex (female) may influence the “partial condemnation” rates, while chick weight at first day may not. For “total condemnation”, flock sex and type of chick may not influence condemnation rates, but mortality rates and broiler weight may have a significant impact.

In breeding farms, pork producers commonly use “bump feeding” as a feeding strategy. This technique consists of increasing daily feed amount on late gestation to improve piglets birth weight. A dose-response arrangement with 4 treatments (1.8, 2.3, 2.8, and 3.3 kg/d) was used to evaluate the effects on female reproductive performance and piglet birth weight. A total of 977 gilts were fed based on a corn-soybean meal diet from day 90 of gestation until farrowing. Gilts were weighed on days 90 and 112 of gestation and at weaning. Born alive and stillborn piglets were weighed within 12 h of birth. Colostrum yield and lactation feed intake were measured in a randomly selected sub-sample of 245 gilts. As expected, body weight gains were different at day 112 (P < 0.001) with the highest values observed in 3.3 kg/d treatment. As the feed amount increased during late gestation, greater were the body losses between d 112 and weaning (P < 0.001). Statistical tendencies for a quadratic effect of feeding level were observed for piglets born alive (P = 0.079), average birth weight of piglets (P = 0.083), and litter weight (P = 0.059). However, there were no differences among treatments on total born and mummified fetuses (P > 0.05). Gilts fed with lower feed amounts during late gestation had reduced stillborn percentages compared to those gilts fed with greater amounts. Colostrum yield and voluntary feed intake decreased linearly (P < 0.05) as the feed amount performed during late gestation increased. In conclusion, increasing the feed intake from day 90 of gestation until farrowing increased gilts body weight and stillborn rate, but reduced the colostrum yield and the lactation feed intake. In addition, there were no effects of the feeding level in late gestation on piglets birth weight.