RELAÇÃO METIONINA E COLINA DIETÉTICA SOBRE O DESEMPENHO DE CODORNAS JAPONESAS (Coturnix coturnix japonica) EM POSTURA

We evaluated the relationship between levels of methionine and choline on the performance of Japanese quails ( Coturnix coturnix japonica ) at the production stage, using 432 birds at 65 days of age and weighing 155g, in a completely randomized design in 4x2 (methionine x choline) factorial arrangement with six replicates and nine birds per unit. The levels of choline and methionine were 0, 200, 400 and 600 ppm and 0.65 and 0.75%, respectively. We analyzed the following variables: egg production (% / hen / day), egg weight (g), egg mass (g egg / hen/ day), feed conversion (g / g) and food intake (g / d). We observed a significant interaction for egg production (P ? 0.01) and egg mass (P ? 0.05) with linear effect for 0.65% methionine and inclusion of increasing levels of choline. There was a quadratic effect of choline levels on feed intake, with 0.65% methionine. The use of choline in diets of quail in production only effects bird performance when 0.65% methionine level is used. Supplementation with choline causes an increase in average egg weight regardless of the level of dietary methionine supplementation. KEYWORDS: laying quails; nutrition; nutritional requirements; performance; sulphur amino acids.