Choline and digestible methionine + cystine supplementation for quail in the laying phase

Abstract

The aim of this study was to evaluate the effect of levels of choline and digestible methionine + cystine in diets for quail in the laying phase. A total of 280 Japanese laying quail were assigned to one of eight treatments in a completely randomized design in a 4 × 2 factorial arrangement consisting of dietary supplementation with four levels of choline (0.0, 0.042, 0.084 and 0.126%) and two levels of digestible methionine + cystine (0.857 and 0.685%), with five replicates and seven birds per plot. The experimental period was 84 days, represented by four 21-day evaluation cycles in which quail performance and egg quality were evaluated. There was no interaction effect between the factors for any of the studied variables, except quail weight. The highest tested levels of methionine + cystine and choline supplementation improved egg weight, feed conversion egg mass‒1 and yolk percentage. By contrast, albumen percentage decreased linearly as choline inclusion in the diet was elevated. The choline supplementation levels induced a quadratic response from eggshell percentage, whose optimum result was estimated at the choline level of 0.05% in the diet. Egg specific gravity decreased linearly as choline supplementation was increased. The indicated level of digestible methionine + cystine in the diet of Japanese quail in the laying phase is 0.857%, while choline should be supplemented at 0.126%.