Exigência de metionina + cistina para frangas de reposiÇão na fase recria de 13 a 18 semanas de idade

Abstract

The methionine + cystine requirement was determined for pullets from 13 to 18 weeks of age and its effect was verified on the laying phase. The experiment was divided into two experimental phases. In the growing phase 560 birds (50% and 50% Lohmann LSL Lohmann Brown) at 13 to 18 weeks of age were distributed in a completely randomized factorial scheme 5x2 (methionine + cystine levels and lineages), with four replications and 14 birds per repetition. The levels of total methionine + cystine studied were 0.399, 0.469, 0.539, 0.609 and 0.679%. When they reached 22 weeks of age, 240 birds were used to assess the residual effects of the diets offered in the growing phase on performance of poultry, egg production and quality. Considering the production phase, there was no effect of the inclusion of methionine + cystine levels in the diet for both strains. The total methionine and cysteine was 0.679% (0.611% of digestible methionine + cystine) for light birds and 0.646% (0.581% methionine + cystine digestible) for brown-egg pullets.