Effect of a Potential Probiotic CandidateEnterococcus faecalis-1 on Growth Performance, Intestinal Microbiota, and Immune Response of Commercial Broiler Chickens

The probiotic effect ofEnterococcus faecalis-1 (isolated from healthy chickens) on growth performance, immune response, and modulation of the intestinal microbiota of broilers was assessed with a total of 100-day-old commercial Cobb chicks. The chicks were randomly divided into two equal groups. The control group received a basal diet, while the test group received a basal diet and was orally supplied withE. faecalisat a dose of 10(8) CFU/bird/day. Results showed thatE. faecalis-1 supplement significantly (P < 0.05) improved the body weight and feed conversion ratio of treated broilers compared with the control ones. The mortality percentage was reduced inE. faecalis-1-supplemented group. The total IgY serum level was significantly (P < 0.05) increased in broilers receivingE. faecalis-1 supplement (7.1 +/- 0.39) compared with the control group (5.8 +/- 0.3), while the serum avidin level was significantly (P < 0.05) decreased inE. faecalis-1-supplemented broilers (76 +/- 11.1). There was no significant change in the immune response towards avian influenza and Newcastle vaccines in both groups. The totalLactobacillusandEnterococcuscounts were significantly (P < 0.05) higher in the cecal contents of broilers givenE. faecalis-1 than those that received the control treatment.E. faecalis-1 supplement enhanced the enzyme activities, antioxidant system, and liver functions of treated broilers compared with those in the control group. Collectively, these results showed thatE. faecalis-1 could promote growth performance and immunological status and convey beneficial modulation of the cecal microbiota in broilers.