EFFECT OF DIETARY SUPPLEMENTATION OF ZEOLITE ON PERFORMANCE AND EGG QUALITY OF LAYING HENS

A 50-d experiment was conducted with 30-wk-old laying hens to investigate the influence of dietary supplementation of zeolite on performance, egg production and egg quality. A total of 24000 hens were fed a control diet or one of three diets containing different levels of zeoliet (20,40 and 60 g/kg-1). Zeolite did not affect feed intake, egg weight. egg volume. composition of yolk. yolk color and yolk volume, compared with the control.. The diets with 20 or 40 g/kg-1 zeoliet increased egg production , egg shell thickness and henday egg production (p<0.01). Egg yolk cholesterol did not differ among treatments. The diet with 20 or 40 g/kg-1 zeoliet resulted in a more intense egg albumen whiteness as measured by the sensory study, compared with the other diets (p<0.05). There was a linear relationship between dietary zeoliet level and egg shell thickness.