Effect of dietary probiotic on performance and humoral immune response

1. The effects of dietary supplementation of a commercial probiotic ( Prote xin(TM)) on daily feed consumption, egg yield, egg weight, food conversion ratio and humoral immune response in layer hens were investigated. In 7 rep licates, a total of 280 40-week-old layers were given diets containing eith er 0, 250, 500 or 750 parts per million (ppm) for 90 d. 2. When compared with the controls, the food consumption, food conversion r atio and the proportions of damaged eggs were lower in the group consuming 500 ppm probiotic ( P< 0.05). 3. There was no significant difference between the controls and the groups receiving 250 and 750 ppm probiotic in food consumption, food conversion ra tio and proportion of damaged eggs. Similarly, the egg yield, egg weight, s pecific gravity, and peripheral immune response showed no statistically sig nificant differences between the groups.