日粮添加不同水平硫酸锌对京红蛋鸡免疫机能和蛋品质的影响

Effects of Zinc Sulfate on Immune Function and Egg Quality in Jinghong Laying Hens

本试验通过研究日粮中添加不同水平硫酸锌对京红蛋鸡免疫机能和蛋品质的影响,探索京红蛋鸡饲料中锌的适宜添加量。选择20周龄540只健康产蛋高峰期的京红蛋鸡,随机分为6个处理组,每个处理6个重复,每个重复15只鸡,分别饲喂6种不同日粮:T1组饲喂基础日粮(对照组,含锌25mg/kg);T2、T3、T4、T5、T6组分别在基础日粮中添加25、50、75、100和125mg/kg硫酸锌(以锌计),预饲期2周,试验期24周。每4周统计破蛋率;分别在33周龄和45周龄末测定蛋品质、血清抗氧化指标和免疫功能相关指标。结果显示:与对照组相比,添加25~125mg/kg硫酸锌对京红蛋鸡破蛋率、蛋壳厚度、蛋壳强度、浓蛋白高度、哈夫单位和蛋黄颜色,血清碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)活性,IgM、IgA含量和新城疫抗体滴度,免疫器官绝对重和免疫器官指数,肝脏铜锌超氧化物歧化酶(CuZn-SOD)活性均无显著影响(P>0.05),但极显著提高了33周龄末京红蛋鸡血清IgG含量(P<0.01)。综合考虑各因素,产蛋高峰期京红蛋鸡日粮中硫酸锌适宜添加量推荐为75mg/kg。

The aim of this study was to evaluate the effects of zinc sulfate on immune function and egg quality by adding different levels zinc sulfate into the basal diet of Jinghong laying hens.Five hundred forty 20-week-old healthy Jinghong laying hens were randomly allotted to six treatments,with 6 replicates per treatment and 15 layers per replicate.These birds were feed with six diets,the basal diet(control group,T1,Zn content was 25 mg/kg),and the diets added 25,50,75,100 and 125 mg/kg zinc sulfate(calculated by Zn)respectively on the basis of the basal diet(T2,T3,T4,T5 and T6 groups).The pre-feeding period was 2 weeks and the experimental period was 24 weeks.The rate of broken and crack egg was calculated every 4 weeks.At 33 weeks and 45 weeks of age,the egg quality,antioxident and immune parameters were observed.The results showed that:Compared to the control group,the supplementation of different levels zinc sulfate did not affect broken and crack egg,eggshell thickness and strength,egg albumin height,Haugh units and yolk color,the serum activities of ALP and LDH,the contents of IgM,IgA and Newcastle disease antibody titer,as well as immune organ weight,organ index and the avtivity of CuZn-SOD in the liver(P>0.05),but increased the serum content of IgG at 33 weeks extremely significantly(P<0.01).In conclusion,the recommended optimal addition amount was 75 mg/kg Zn from zinc sulfate in the diet.