Requirements of methionine plus cystine for male broilers from 1 to 21 and 22 to 42 days old on climate region

Two experiments were conducted to determine the nutritional requirements of total methionine + cystine for Ross male broilers from I to 2 1,and 22 to 42 (lays old oil tropical climate. The following parameters Were evaluated: feed intake, weight gain, feed:gain ratio and absolute weights and yields of carcass, noble cuts (chest, thighs and (drumsticks) and abdominal fat. The experiment was analyzed as I complete randomized design with six levels of methionine + cystine and four replicates Of 12 animals, in a total of 288 birds for each experiment. The diets were formulated to meet the bird nutricional re(requirements, except for methionine + cystine levels. The diets were supplemented with DL-methionine at levels of 0, 0.08, 0.16, 0.24, 0.32, and 0.40%, resulting in experimental diets with 0.69, 0.77 0.85, 0.93. 1.01 and 1.09% of methionine + cystine, for (lie period from I to 2 1 daysold and 0.61, 0.69, 0.77, 0.85, 0.93, and 1.01% of methionine + cystine, for the period From 22 to 42 days old. Quadratic effects of methionine + cystine levels on weight gain,and feed:gain ratio, from I to 2 1 days old, and oil feed intake, weight gain, feed:gain ratio, absolute weights of carcass,and chest and yields of carcass. thighs and drumsticks, from 22 to 42 days old, were observed. According to the performance data, the nutritional requirements of methionine + cystine for male Ross broilers were estimated in 0.96 and 0.89% from 1 to 21 and 22 to 42 days old, respectively.