Electrolyte balance in diets with reduced protein for semi-weighted laying hens in the second production cycle

The objective was to evaluate the effect of electrolyte balance in diets with reduced protein for semi-weighted Bovans Goldline laying hens in the second production cycle. The design was completely randomized with five treatments and seven replicates of six birds per experimental unit. Treatment 1 consisted of a control diet containing 165.0 g/kg crude protein (CP), formulated with the addition of DL-methionine to meet birds requirements during the experimental period. To compose the treatments 2-5 (BE149, BE167, BE185 and BE203), a basal diet with reduced protein (135.0 g/kg CP) supplemented with synthetic amino acids DL-methionine, L-lysine, L- threonine, L-valine and L-tryptophan was formulated. This basal diet was supplemented with potassium carbonate, to replace the inert, so as to provide four levels of potassium (5.86, 6.56, 7.26 and 7.96 g/kg) corresponding to the electrolyte balance of 171, 149, 167, 185 and 203 meq/kg, respectively. There was increased linear effect for feed intake and decreasing linear effect for albumen weight and yolk percentage and quadratic effect for conversion per dozen and per egg mass. Crude protein is recommended at 135.0g/kg with 6.77 g/kg potassium and electrolyte balance of 172.51meq/kg in the diet of semi-weighted laying hens in the second production cycle.