Efficacy of natural zeolite and pigments on yolk color and performance of laying hens

Abstract

An in vivo study was conducted to evaluate pigment adsorptive ability of a natural zeolite in laying hens. This experiment was performed with three hundred sixty Hy-line W-36 strain of laying hens at 43 weeks of age. After a two weeks adaptation period, they received six experimental diets with a 3 × 2 factorial arrangement in a completely randomized design. The experimental groups were fed with cornsoy- wheat based diets containing three levels of natural zeolite (0.0, 1.5 and 3.0%) and 2 levels of synthetic pigment (0.0 and 0.04%) for a 6-week period. Each treatment contained 60 birds, which were randomly divided into 4 replicates of 15 birds each. The results showed that egg production, egg weight, shell thickness and the shell percent values did not significantly differ between treatments, but that the yolk color index was significantly reduced and increased by the addition of zeolite and pigment levels to the diet, respectively.

Key words: Natural zeolite, pigment, yolk color, laying hens.