Broilers' lysine and methionine + cystine levels in initial phase

Abstract

An experiment was conducted to determine the digestible lysine and methionine+cystine requirements in male broiler chickens from 1 to 21 days old. Chicks were submitted to diets with 3 lysine levels (0,90%, 1,09% and 1,30%) and 3 met+cis levels (0,70%; 0,84% and 1,01%). The experimental design was entirely casual with 9 treatments in factorial design 3x3 (lysine levels and sulfurous amnoacid levels) and 5 repetitions with 40 male chicks. Performance was superior in the medium and high levels of lysine. The met+cis influenced significantly for WG. There was interaction for FC; the level 1,09% of lysine was the best in the 3 met+cis levels. The lysine levels influenced the rate of lysine efficiency (TEL) and the rate of methionine efficiency (TEM) was influenced by the lysine as for the met+cis, as an interaction. The analysis of the breast meat revealed that the lysine influenced DM and CP, even so it did not affect EE; met+cis levels did not affect this parameter. So we concluded that the levels 1,09% e 0,84%, respectively for lysine and sulfurous amnoacids, obtained the best performance and carcass parameter.