Decreasing dietary levels of crude protein and supplementation of methionine and lysine for light laying hens

The effect of decreasing dietary CP and supplementation of lysine and methionine+cystine on the performance of 270 laying liens Lohmann LSL strain was evaluated in this trial. The birds averaging 26 weeks of age were allotted to a stocking rate of 562 cm(2)/bird as a completely randomized design with five replicate of six birds. The treatments were as follows: T-1 = control diet (CD) with 16.5% CP, 0.80%, of lysine (L) and 0.70%, of methionine+cystine (MC): T, = 15.25% CP, 0.73% of L and 0.64% of MC: T-3 = 14%CP, 0.66% of L and 0.58% of MC: T-4 = 15,25% CP with 0.80% of L and 0.64% of MC; T-5 = 14%, CP with 0.80% of L and 0.58% of MC; T-6 = 15,25% CP with 0.73% of L and 0.70% of MC: T-7 = 14% CP with 0.660% of L and 0.70 of MC; T-8 = 15.25% CP with 0.80% of L and 0.70% of MC and, T-9 = 14% CP with 0.80% of L and 0.70% of MC. The diets contained 2,800 kcal of ME. Diets were suppplemented with amino acids at 15.25 and 14.0% of crude protein to show levels of Lys, MC or L+MC similar to control. The birds were fed 110 g of diet/day and water ad libitum and were submitted at a program of light of 17 hours. The variables were evaluated during four periods of 28 days. The decreasing dietary CP from 16.5 to 14%, did not affect bird performance, whereas the lysine supplementation of lower protein diet decreased egg production and egg mass and feed:egg mass ratio and feed:egg dozen ratio in relation to control.