忍冬藤提取物对热应激蛋鸡产蛋性能、蛋品质及免疫功能的影响OA

This study aimed to investigate the effects of adding different doses of Lonicera japonica extract(LJE;at 0.5%and 1.0%)to the diet on egg production performance,egg quality,and immune function of heat-stressed laying hens.A total of 720 healthy Hy-Line Brown laying hens were randomly divided into four groups:a control group(CON),a heat stress group(HS),a heat stress+0.5%Lonicera japonica extract group(HS+LJE-L),and a heat stress+1.0%Lonicera japonica extract group(HS+LJE-H).During the experimental period,the control group was reared at an appropriate temperature,while the other three groups were exposed to high temperatures to induce heat stress.The results showed that compared with the HS group,the LJE-added groups significantly improved the egg production rate(P<0.05),reduced the feed-to-egg ratio and the rate of defective eggs(P<0.05);among them,the effect of the 1.0%addition was better than that of the 0.5%addition.Specifically,the egg production rate in the HS+LJE-L group increased by 8.03%,while in the HS+LJE-H group,it increased by 12.06%.In terms of egg quality,LJE significantly increased eggshell thickness,eggshell strength,and Haugh units(P<0.05),while reducing the yolk index(P<0.05).Additionally,LJE significantly enhanced the immune function of heat-stressed laying hens,as evidenced by significantly increased levels of IL-10 and IgA(P<0.05)and decreased levels of TNF-α(P<0.05)in the serum,but had no significant effect on IgG levels(P>0.05).Other serum indicators such as total antioxidant capacity(T-AOC),glutathione peroxidase(GSH-Px)activity,superoxide dismutase(SOD)activity,and malondialdehyde(MDA)content were also measured in this study,further confirming the antioxidant effect of LJE.In conclusion,adding 0.5%～1%Lonicera japonica extract to the diet can alleviate the adverse effects of heat stress on laying hens,providing a scientific basis for its scientific application in laying hen farming.