Abstract:

In order to investigate the effects of Chinese herbal extracts on physiological function of broilers, 3 mixed Chinese herbal extracts(Ⅰ,Ⅱ and Ⅲ) were added to the drinking water of broilers from 1 to 28 days old (concentration was 0.5%) respectively, and then intervals for 7 days, the physiologic and immunological parameters were determined, such as index of immune organs, serum proteins(total protein, albumin, globulin), serum enzymes(AST, ALT, LDH, ALP), Newcastle disease virus(NDV) HI antibody titers, interleukin-2(IL-2), interleukin-3(IL-3), average daily gain, feed conversion ratio and mortality rate. The results showed that the index of immune organs, serum proteins and some serum enzymes(AST, ALT, LDH) were not influenced by supplement with the 3 mixed Chinese herbal extracts (P＞0.05). Level of ALP in serum of Ⅱgroup was higher than that of the control(P＜0.05) at the 21th and 28th days. NDV HI Antibody titers of the 3 mixed Chinese herbal extracts groups were higher than that of the control(P＜0.05) at 21th day, and at the 28th day extractⅠgroup was obviously higher than the control(P＜0.01), Ⅲ group was also higher than the control(P＜0.05). IL-2 ofⅠand Ⅲ groups have higher levels than that of the control at the 21th day(P＜0.05), but to the 28th day only Ⅰgroup was still higher than the control(P＜0.05). Level of IL-3 of Ⅰgroup was higher than that of the control at 28th day(P＜0.05). When broilers were 28 days old, average daily gain of Ⅰand Ⅱ groups was higher than that of the control, the highest was Ⅱ group 72.72 g/d. Compairing with the control group, feed conversion ratios of Ⅰand Ⅱ groups were lower, the lowest was Ⅱ group 2.08. The lowest mortality rate was Ⅰgroup 1%. All results suggest that the 3 mixed Chinese herbal extracts have high security, and can impove physiological function of broilers in some ways. The extract Ⅰhas a significant effect on delaying the decline of antibody level, while the extract Ⅱis helpful to improve the production performance of broilers.