Yeast extract and prebiotic in pre-initial phase diet for broiler chickens raised under different temperatures

Objetivou-se nesta pesquisa avaliar o desempenho, o rendimento de carcaça e a morfometria intestinal de frangos de corte criados em diferentes temperaturas e que receberam na fase pré-inicial ração contendo ou não extrato de leveduras e prebiótico. Foram utilizados 1.440 pintos machos de 1 dia de idade, criados em diferentes câmaras climáticas. As rações, acrescidas ou não de extrato de leveduras e prebiótico, foram oferecidas somente na fase pré-inicial (1 a 7 dias). A partir do oitavo dia, todas as aves receberam a mesma ração, reajustada de acordo com as recomendações usuais. Adotou-se o delineamento experimental inteiramente casualizado em arranjo fatorial 3 × 2 × 2, composto de três temperaturas de criação (calor, conforto e frio) e dois níveis de extrato de leveduras (com ou sem) e prebiótico (com ou sem). O desempenho das aves foi avaliado considerando o ganho de peso, o consumo de ração, a conversão alimentar e a viabilidade aos 42 dias de idade. Também foram avaliados o rendimento de carcaça e a morfometria intestinal. O calor ambiente prejudicou o desempenho e o rendimento de carcaça. A inclusão de prebiótico na ração pré-inicial aumentou o ganho de peso e melhorou a conversão alimentar das aves criadas no calor. A inclusão dos produtos na ração de frangos de corte criados em ambiente de calor e no frio tem efeito benéfico sobre as vilosidades das aves.

Polymorphism analysis of the hsp70 stress gene in Broiler chickens (Gallus gallus) of different breeds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Levels of digestible threonine for male broilers from 1 to 7 days of age

The influence of threonine has been studied in broilers; however, information concerning the phase from 1 to 7 d is lacking. In this study, we evaluated the effects on performance and body composition and the relationship with other amino acids with respect to digestible lysine and total glycine + glycine. Research on the initial 7-d phase of broiler growth is still poorly studied, even though it is important, especially in nutrition. It was found that threonine had a great influence on the broilers at that phase and nutritional recommendations need constant evaluation. In conclusion, the digestible threonine: digestible lysine ratio and digestible threonine: total glycine + serine ratio recommended for better performance and body composition are 0.68 and 0.40, respectively. The levels of digestible threonine and total glycine + serine that provide the best results are 0.864 and 2.192%, respectively.

Protein levels and environmental temperature effects on carcass characteristics, performance, and nitrogen excretion of broiler chickens from 7 to 21 days of age

This trial was conducted to evaluate the utilization of low-protein diets formulated based on the ideal protein concept for broiler chickens from 7 to 21 days of age reared at different environmental temperatures. Nine hundred male Cobb-500® chickens were used. At day seven chicks were distributed according to a completely randomized design in a 3 x 3 factorial with four replications of 25 birds each. It was used three crude protein levels in the diet (21.5; 20.0 and 18.5%) and three environmental temperatures (low, thermoneutral and high). The performance, carcass characteristics (yield and chemical composition), and nitrogen ingestion and excretion were assessed. There was no significant interaction among the factors for the evaluated variables. Environmental temperatures affected differently chicken performance. High environmental temperature resulted in lower weight gain and higher wing fat percentage, whereas cold temperature resulted in higher feed conversion. on the other hand, low-protein diets decreased weight gain, breast yield, nitrogen excretion and influenced breast and wings chemical composition. Birds reared at high environmental temperature showed lower nitrogen intake and excretion. The results showed that the decrease in protein levels from 7 to 21 days of age contributed to lower nitrogen excretion in broiler chickens, but impaired performance and carcass characteristics independent of rearing temperature.

Hepatic mRNA expression and plasma levels of insulin-like growth factor-I (IGF-I) in broiler chickens selected for different growth rates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilização de Prebióticos, Probióticos ou Simbióticos em Dietas para Frangos

Foi investigado o efeito da substituição de antibióticos por prebiótico, probiótico e simbiótico em dietas para frangos de corte de 1 a 45 dias de idade. Foram utilizados 750 pintos de 1 dia de idade, distribuídos em cinco tratamentos, sendo: T1-sem aditivos, T2-antibiótico (Olaquindoxâ e Nitrovinâ ), T3-prebiótico (0,2% de parede celular de S. cerevisiae), T4-probiótico (300 ppm de B. subtilis) e T5-simbiótico (T3 + T4). O desempenho dos frangos de 1-45 dias de idade foi influenciado pelos diferentes tratamentos, sendo o melhor ganho de peso observado em aves que receberam o simbiótico, seguido daquelas com antibiótico, prebiótico e probiótico. O pior ganho de peso foi observado nas aves que não receberam qualquer tipo de aditivo na dieta. A conversão alimentar, no período de 1 a 45 dias de idade, também foi influenciada pelo tipo de aditivo. As aves que não receberam suplementação apresentaram pior conversão alimentar quando comparadas com as aves dos demais tratamentos. Os resultados deste experimento permitem concluir que a substituição de antibióticos por simbióticos na ração de frangos é uma alternativa viável, pois não compromete o desempenho das aves, contudo a ausência de aditivos na dieta piora o desempenho das mesmas.

Effect of environmental temperature on immune response of broilers

Several studies demonstrate that environmental temperature can influence the immune response of poultry. The objective of this research was to determine at which stage in the life of a bird this effect is greatest. In experiment 1, broiler breeder eggs were incubated at three different temperatures (36.8+/-0.2, 37.8+/-0.2, and 38.8+/-0.2degreesC from the 13th day of incubation to hatching. After hatching, birds were raised in thermoneutral temperature. In experiment 2, 144 1-d-old broiler chicks were distributed into three environmental chambers with different temperatures (18+/-2, 24+/-2, and 32+/-2degreesC). In both experiments, the humoral immune responses to Newcastle disease virus (NDV) and infectious bursal disease (IBDV) were evaluated. NDV and IBDV antibody titers were not significantly different (P > 0.05) among treatments.

Evaluation of yeast cell wall on the performance of broiles fed diets with or without mycotoxins

This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.

Requirement for cobalamin by Salmonella enterica serovars Typhimurium, Pullorum, Gallinarum and Enteritidis during infection in chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The contribution of genes required for anaerobic respiration to the virulence of Salmonella enterica serovar Gallinarum for chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification and antimicrobial susceptibility patterns of Pasteurella multocida isolated from chickens and japanese quails in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A defective mutant of Salmonella enterica Serovar Gallinarum in cobalamin biosynthesis is avirulent in chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Humoral and cellular immune response generated by different vaccine programs before and after Salmonella Enteritidis challenge in chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental infection by Salmonella enterica subsp enterica serovar kottbus in day-old broiler chickens

The strain used in this work was a Salmonella enterica subsp enterica serovar Kottbus (6,8:e,h:1,5) isolated from imported day-old ducklings in Laboratório Nacional Agropecuário (LANAGRO/SP) of the Ministry of Agriculture of Brazil (MAPA). In view of the lack of information available about this Salmonella isolate and also because it was detected in day-old imported birds, this study was carried out to investigate the dissemination of S. Kottbus among newly hatched chicks. The birds were placed in three groups: one group of 20 birds received 0.1 mL of S. Kottbus culture containing 1.2 x 10(8) CFU/mL, the second group of 20 birds was inoculated with 1.2 x 10(5) CFU/mL and the third group of 10 birds was untreated (control group). Results were similar for both infected groups. The bacterium was recovered from cloacal swabs collected from the first day following the experimental infection until the end of the trial (42 days post-inoculation). At 15 and 42 days post-inoculation (dpi), half of the birds of each group were killed for bacteriological examination of cecal contents, liver and spleen. At 15 dpi, viable cell counts of S. Kottbus were obtained in all kinds of samples. At 42 dpi, Salmonella was present in the liver and spleen of few birds, but in large amounts in the cecal contents of almost all birds.