RESUMEN
The primary goal of this research was to elucidate the novel influence of Brachiaria decumbens supplementation on broiler chicken growth performance, nutritional digestibility, cecal microbiota, intestinal histomorphology, carcass characteristics, and meat quality. A total of 300 male day-old Ross 308 broiler chickens were randomly subjected to six different treatment groups having five replicates per treatment with 10 birds in each replicate. In treatment 1, broiler chickens were fed commercial diets with no added additives; in treatment 2, broiler chickens were offered commercial diets containing 100 mg/kg of the antibiotic oxytetracycline. However, in treatments 3, 4, 5, and 6, broiler chickens received similar commercial diets supplemented with 25 mg/kg, 50 mg/kg, 75 mg/kg, and 100 mg/kg of B. decumbens ground leaf powder, respectively, without antibiotics. Throughout the 42-day trial, the body weight gain and total feed intake for each replicate were recorded every week to determine the growth performance. Then, on 21th and 42nd day, ten broilers from each treatment (two in each replicate) were randomly selected and slaughtered to assess the digestibility of nutrients, histomorphology of the small intestine, the population of the cecal microbiota, carcass characteristics, as well as quality of both breast and drumstick muscle. There were differences (p < 0.05) in the growth performance, apparent ileal nutrient digestibility, intestinal histomorphology, carcass characteristics, and meat quality. Animals supplemented with 25 mg/kg of B. decumbens had higher growth performance and better ileal nutrient digestibility of protein, fiber, and ether extract, as well as higher villi height and carcass percentage with superior meat quality. Besides, the growth of E. faecalis during the starter phase was inhibited. In summary, B. decumbens supplementation at 25 mg/kg may be suggested as an optimal dose of as a prophylactic as well as an alternative for antibiotic growth promoter in stimulating the productivity of commercial broilers. This unconventional phytobiotic supplementation could be the key to replacing unnecessary antibiotics used in poultry feed.