Electrolyte balance and crude protein requirement of laying Japanese quail Níveis de balanço eletrolítico e proteína bruta para codornas japonesas na fase de postura

The objective of this study was to evaluate the effects of two levels of crude protein and ?ve levels of electrolyte balance on the performance and egg-quality of laying Japanese quail. Six hundred 45-dayoldquails were distributed in a randomized-block design with a 5 × 2 factorial arrangement comprising ten treatments, ?ve replicates, and 12 birds per experimental unit. The electrolyte balance levels were 50, 125, 200, 275, and 350 mEq kg –1 of diet, and crude protein (CP) levels were 210 and 240 g kg -1 . The performance and egg-quality variables assessed were: feed intake, feed conversion, egg-laying percentage, egg weight and mass, and albumin, yolk and shell weight. There were no interactions among the studied factors. The electrolyte balance and crude protein levels did not signi?cantly affect the performance variables. However, increased shell weight of eggs stored for seven days was observed at an electrolyte balance level of 200 mEq kg –1 . With regard to the CP levels, increased egg weight was observed at 28 days at a level of 210 g kg -1 , whereas increased albumin weight was observed at 35 days of storage at a level of 240 g kg -1 . A tendency toward an increase in egg albumin weight during the storage period of 14 days was observed. Based on the ?ndings of this study, it is recommended that the diet for Japanese quails in the laying phase be formulated with an electrolyte balance of 50 mEq kg –1 and 240 g kg -1 of crude protein This diet did not have a negative effect on productive performance, and by increasing the weight of egg albumin, eggs can be stored for a longer duration, thus demonstrating an