DIGESTIBLE TRYPTOPHAN DIET LEVELS AND EGGS QUALITY OF JAPANESE QUAIL FROM 21 TO 30 WEEKS OF AGE

Abstract

The aim of this study was to evaluate the digestible tryptophan level(dig. Trp) for laying Japanese quail diets. Four hundred Japanese quail aging 21 to 30 weeks were housed in laying cages, with initial average weight of 158.50 g and egg production of 84.50%. The experimental arrangement consisted on a randomized design, containing eight blocks, five of tryptophan levels (0.12, 0.16, 0.20, 0.24 and 0.28% dig. Trp), eight replicates of ten birds and three experimental periods of 21 days. The evaluated parameters were feed intake (g/bird/day), egg production (%/bird/day), average weight of eggs (g), weights of yolk (g), albumen (g), shell (g), percentage of shell (%), specific gravity (g/cm3) and Haugh units. The tryptophan level affected (P<0.05) all parameters, except feed intake, average eggs weight and weight of yolk. The performance of quails using the statistical adjustment through quadratic regression, broken-line regression model, suggested that the minimum requirement of diets of digestible tryptophan is 0.21% of the diet, allowed the daily intake of 45.0 mg of tryptophan per bird, and the corresponding ratio between digestible tryptophan and digestible lysine was 21%.

KEY-WORDS:

Amino acids. Coturnix coturnix japônica. Exigency Quality of eggs.