RESUMEN
The effects of in ovo feeding with threonine (Thr) on intestinal morphology, ileal gene expression and performance of broiler chicken between 1 and 21 d of age (d) were assessed. On day 17.5 of incubation, fertile eggs were randomly allotted to 5 treatments of Thr injection in the amniotic fluid (0; 1.75; 3.5; 5.25; 7%, corresponding to 17.5; 35; 52.5 and 70 mg Thr/mL). After hatch, chicks were given a commercial corn-soybean diet up to 21 d. Daily feed intake (FI), body weight (BW), and food conversion ratio (FCR) were measured from 1 to 7, 14, and 21 d of age. The ileal gene expression of mucin (MUC2), peptide transporter (PepT1), and aminopeptidase enzyme (APN) were evaluated on day of hatch and at 21 d, as well as intestinal morphometric traits. In ovo feeding with threonine significantly increased final weight (FI) and weight gain (WG) and decreased FCR in the period from 1 to 21 d. Threonine levels affected beneficially the villus height, vilo: crypt ratio and villus area on day of hatch and at 21 d. At hatch, all Thr levels increased the expression of MUC2 and PepT1 compared to the control group. APN expression also increased, but for the lowest and the highest threonine levels (1.75 and 7%). At 21 d, there was no effect of threonine on the expression of MUC2, PepT1, and APN. In conclusion, in ovo threonine feeding beneficially affected the morphological and functional development of the intestinal mucosa, which ensured improved performance of chicks at hatch and at 21 d.
Asunto(s)
Pollos/fisiología , Intestino Delgado/efectos de los fármacos , Treonina/farmacología , Amnios , Animales , Antígenos CD13/genética , Antígenos CD13/metabolismo , Embrión de Pollo , Pollos/crecimiento & desarrollo , Expresión Génica , Íleon/metabolismo , Intestino Delgado/crecimiento & desarrollo , Mucinas/genética , Mucinas/metabolismo , Transportador de Péptidos 1/genética , Transportador de Péptidos 1/metabolismo , Treonina/administración & dosificaciónRESUMEN
As aves silvestres podem ser reservatório de bactérias patogênicas e atuar como veiculadoras desses microrganismos para o ambiente, os animais domésticos e o homem. Portanto, o objetivo deste trabalho foi verificar a ocorrência de Campylobacter spp., Yersinia enterocolitica e Salmonella enterica em aves silvestres capturadas nas áreas próximas de aviários e em frangos de corte alojados nesses estabelecimentos, além de verificar a presença dos genes cdtA, cdtB e cdtC nos isolados de Campylobacter e identificar os sorotipos de Salmonella encontrados. Amostras de fezes de 189 aves silvestres capturadas com redes de neblina nas áreas próximas de 10 aviários e de 200 frangos de corte foram processadas para pesquisa de Campylobacter spp., S. enterica e Y. enterocolitica. Duas espécies de aves silvestres, Sicalis flaveola (canário-da-terra) e Zonotrichia capensis (tico-tico), foram positivas para Salmonella e Campylobacter, respectivamente. Foram isolados Campylobacter spp., S. enterica e Y. enterocolitica de frangos. Todos os isolados de Campylobacter analisados apresentaram os genes cdt. Em dois aviários, Campylobacter foi isolado tanto de frangos como de aves silvestres, entretanto a contaminação mútua entre essas aves não foi comprovada. Este foi o primeiro relato de isolamento de Campylobacter de Z. capensis e de Salmonella do sorotipo Derby de S. flaveola.(AU)
Wild birds can be reservoirs of pathogenic bacteria and act as carriers of these microorganisms to the environment, domestic animals, and humans. Therefore, this study had as objective to verify the occurrence of Campylobacter spp., Yersinia enterocolitica and Salmonella enterica in wild birds captured in the surroundings of the aviaries and in the broilers housed in these establishments. The presence of the cdtA, cdtB and cdtC genes in Campylobacter isolates was also investigated and Salmonella serotypes were identified. Stool samples from 189 wild birds captured with mist nets in around 10 aviaries and from 200 broilers were processed for Campylobacter spp., S. enterica and Y. enterocolitica research. Two species of wild birds, Sicalis flaveola (Saffron Finch) and Zonotrichia capensis (Rufous-collared Sparrow) were positive for Salmonella and Campylobacter, respectively. Campylobacter spp., S. enterica and Y. enterocolitica were isolated from broilers. The cdt genes were found in all Campylobacter isolates. In two aviaries, Campylobacter was isolated from both broilers and wild birds, however the mutual contamination among these birds has not been shown. This was the first report of Campylobacter isolation from Z. capensis and of Derby Salmonella serotype isolation from S. flaveola.(AU)