Total sulfur amino acid levels for semi-heavy weight laying hens after forced moult.

摘要

162 brown laying hens after the induced moult were randomly assigned to three treatments with 9 replicates containing 6 birds each. The treatment consisted of adding 0.45, 0.60 and 0.75% total sulfur amino acids (TSAA) to the diet for 30 days after the end of the induced moult (postmoult phase). After 30 days, each treatment used in the postmoult phase was applied to the production phase of the layers. A completely randomized design in a 3x3 factorial arrangement was used in the study (levels of TSAA in the postmoult phase - 0.45, 0.60 and 0.75% x TSAA levels in the production phase - 0.45, 0.60 and 0.75%). The treatments in the production phase were composed of three replicates with 6 birds each. The performance and egg quality of the layers were evaluated for 4 periods of 21 days during the production phase. At postmoult phase, the lower TSAA level (0.45%) resulted to lower (P<0.01) feed intake, TSAA intake and body weight. The TSAA levels used in the postmoult phase only affected (P<0.05) the egg weight. 0.45% TSAA used in the production phase was not enough to supply the birds' amino acid requirements as shown by the layers' poor performance (P<0.01). On the other hand, 0.60% TSAA may be recommended for postmoult and second production phases.