عنوان مقاله [English]
A total of 300 day-old chicks in a completely randomized design using a factorial arrangement with 4 treatments were used to study the effects of different levels of nutrients and Virginiamycin on the body weight and feed conversion of broilers. Test diets were formulated to provide 100 or 110 percent of protein recommended by NRC and was fed either with or without 25 ppm of Virginiamycin to 3 pens of 25 chicks. Weekly body weight and feed conversion were measured and at the end of the trial, two chicks of each pen were selected, killed and dressing percentage and feed conversion were determined. Data from this experiment showed that the 6 weeks age birds, which received Virginiamycin, at two diets, were significantly (p < 0.01) heavier. Addition of 25ppm Virginiamycin also improved (p < 0.01) body weight in diet of NRC + 110% CP. Addition of 25 ppm Virginiamycin significantly (p < 0.01) improved feed conversion rate at the diet of NRC + 110% CP.