Effects of Dietary Supplementation of Soy Isoflavones on the Performance and Egg Quality in Native Chinese Breeder Hens

ABSTRACT To investigate the effects of soy isoflavones (ISF) on the laying performance of Xueshan breeder hens at different phases of the egg production cycle, 32 weeks (wks) old local Chinese breeder hens were assigned to two groups with three replicates (750 hens/replicate) for control and treatment groups. Then every group was divided into three sub-groups following 4, 12, and 20 wks administration of control or ISF diet. General Linear Model procedure was used (2× 3), and treatments were considered of two factors (diets and time) with different levels (control and ISF diets; 4, 12, and 20...