Effect of the use of probiotic and antibiotic on the performance, yield and carcass quality of broilers

Two thousand and four hundred broiler chicks were assigned to a completely randomized design in a 2 x 2 x 2 (sex. with and without probiotic. with and without antibiotic) factorial arrangement, totalizing eight treatments and six replicates with 50 birds in each one. Independently of supplementation fed, the males were always heavier than the females. However. the analyses performance showed higher body weight and weight gain for males fed antibiotic when compared to the non supplemented. The use of antibiotic increased feed intake up to 42 days of age, but it did not affect the other characteristics. Probiotic supplementation negatively influenced the body weight, weight gain and feed intake of the broilers front either 1 to 21 or 1 to 42 days of age. There was a probiotic x antibiotic interaction for carcass yield of the broilers, and the highest carcass yield were obtained when the products were associated in the diet. Neither probiotic nor antibiotic affected cut-part yield (head, fect, wings, leg, breast and hack), viscera Yield (heart, liver and non edible viscera), abdominal fat and sensorial characteristics (intensity of aroma, stranger aroma, flavor, stranger flavor, tenderness, juiciness, acceptability, characteristic color and overall aspect) of breast and leg meats. No beneficial effects of the probiotic supplementation in broiler diets were observed in the present study.