Abstract: A 28-day feeding trial was employed to evaluate whether the used in broiler’s diet had any deleterious effects on growth,serum parameters of broiler chicken. 192 21-day old broilers were divided into four groups. Fed diet containing nothing,radix astragalus(RA),fermented radix astragalus extraction(FRAE) and astragalus polysaccharide(AP) separately. Feed efficiency and daily gain in the whole experiment were determined,some serum parameters were measured,the post-mortem organ coefficients were calculated and organ analysis were performed at the end of experiment.The results showed that:①Supplementation with RA significantly decreases average daily gain and average daily feed index(P＜0.05),supplementation with FRAE significantly decreases feed/weight gain(P＜0.05);②Supplementation with FRAE significantly decreases the activities of serum LDH(P＜0.05)compared with the RA group. Supplementation with RA significantly decreases the activities of serum r-GT(P＜0.05)compared with the control group;③No histopathological damages were detected. From the research,it was concluded that there were obvious promotional effects of the FRAE on the broiler chicken’s growth and health.

Key words: fermented radix astragalus extraction; serum biochemical parameters; broiler chicken