The effect of intra-amniotic and posthatch dietary synbiotic administration on the performance, intestinal histomorphology, cecal microbial population, and short-chain fatty acid composition of broiler chickens.

This study evaluated the effect of intra-amniotic synbiotic inclusion and continued synbiotic supplementation in the diet on the performance, intestinal epithelium integrity, and cecal microflora of broiler chickens. In Experiment 1, 510 eggs containing viable embryos were divided into 3 groups of 170 eggs each. The first group was not injected and served as a negative control ( NC: ). The next group was injected with 0.9% NaCl and was the positive control ( PC: ). The synbiotic-injected group ( S: ) was injected with a 0.5% inulin and 1 × 10 Enterococcus faecium solution. The non-injected and synbiotic injected groups were further divided into 2 sets for Experiment 2 and the birds were offered either a basal or synbiotic supplemented diet (1% inulin and 2 × 10 E. faecium cfu/kg feed). One hundred ninety-six broiler hatchlings were randomly allocated in a 2 × 2 factorial arrangement that included an intra-amniotic treatment (non-injected or synbiotic injected) and a dietary treatment (basal or synbiotic supplemented diet). The results showed that the administration of an intra-amniotic synbiotic to embryonated eggs on d 17 of incubation did not affect the hatchability or hatching weight of the birds. However, intra-amniotic synbiotic inclusion had a positive effect on FCR at d 0 to 42 (P = 0.041) and d 22 to 42 (P = 0.036). There was no significant interaction effect on the growth performance of the birds between the intra-amniotic and dietary synbiotic treatment during different or entire experimental periods. Villus height and goblet and proliferating cell nuclear antigen ( PCNA: ) positive cell counts were positively influenced by intra-amniotic and dietary synbiotic treatments. Our results also indicated that intra-amniotic synbiotic injection followed by dietary supplementation with a synbiotic significantly increased Lactobacillus colonization and decreased coliform population in the broiler cecum. Cecal butyric acid concentration increased proportionally to the cecal Lactobacillus count with dietary synbiotic supplementation on d 42. In summary, combined intra-amniotic and dietary synbiotic treatments improved broiler intestinal integrity and increased cecal beneficial bacteria populations.