不同锌源对产蛋后期蛋鸡锌沉积、碳酸酐酶活性、蛋壳钙含量、蛋壳质量和生产性能的影响

Effects of different zinc dources on zinc deposition,carbonic anhydrase activity,eggshell calcium content,eggshell quality and production performance of laying hens during the late laying period

为研究蛋氨酸螯合锌(Zn-Met)和硫酸锌(ZnS)对产蛋后期蛋鸡锌沉积、碳酸酐酶(CA)活性、蛋壳钙含量、蛋壳质量和生产性能的影响,试验选用产蛋率基本一致的70周龄海兰褐蛋鸡144只,随机分为2组,每组6个重复,每重复12只鸡,分别饲喂添加ZnS与Zn-Met的试验饲粮,试验期70 d。ZnS组与Zn-Met组锌在基础饲粮中添加量均为80 mg/kg。结果表明:(1)与ZnS组相比,Zn-Met组血清、肝脏和蛋壳腺锌含量及CA活性提高(P<0.05),锌含量分别提高了13.22%、10.36%和11.73%;CA活性分别提高了15.01%、10.74%和10.37%。(2)Zn-Met组蛋壳钙含量比ZnS组提高了3.72%(P<0.05)。(3)与ZnS组相比,Zn-Met组试验第5周和第10周蛋壳强度和蛋壳厚度提高(P<0.05),蛋壳强度分别提高了8.51%和13.10%,蛋壳厚度分别提高了5.26%和7.89%。蛋形指数、蛋白高度、哈氏单位和蛋黄颜色ZnS组与Zn-Met组之间无显著差异(P>0.05)。(4)生产性能不受饲粮中添加ZnS和ZnMet的影响(P>0.05),但Zn-Met组软破蛋率比ZnS组降低了78.95%(P>0.05)。由此可见,饲粮添加Zn-Met较ZnS可促进产蛋后期蛋鸡肝脏和蛋壳腺锌沉积,进而提高肝脏和蛋壳腺CA活性,从而促进蛋壳钙沉积,导致蛋壳厚度和蛋壳强度的提高,最终降低软破蛋率。

This experiment was conducted to study the effects of methionine chelated zinc(Zn-Met)and zinc sulfate(ZnS)on zinc(Zn)deposition,carbonic anhydrase(CA)activity,eggshell calcium content,eggshell quality and production performance of laying hens during the late laying period.In this experiment,a total of 144 healthy Hy-Line Brown laying hens of 70 weeks old with similar laying rate were randomly divided into 2 groups with 6 replicates per group and 12 hens per replicate.Laying hens were fed with the same basal diet supplemented with 80 mg Zn/kg from Zn-Met or Zn S for 70 days.The results showed as follows:(1)Compared with those in the ZnS group,Zn contents and CA activities of serum,liver and eggshell gland in the Zn-Met group were increased(P<0.05),Zn contents were increased by 13.22%,10.36%and11.73%,and CA activities were increased by 15.01%,10.74%and 10.37%,respectively.(2)The calcium content of eggshell in the Zn-Met group was increased(P<0.05)by 3.72%compared with that in the ZnS group.(3)Compared with the ZnS group,Zn-Met group increased(P<0.05)eggshell strength and eggshell thickness at the 5th and 10th weeks of the test,eggshell strength were increased by 8.51%and 13.10%,and eggshell thickness were increased by 5.26%and 7.89%,respectively.There were no significant differences(P>0.05)in egg shape index,albumen height,Haugh unit and yolk color between Zn-Met and Zn S groups.(4)The production performance was not affected(P>0.05)by the addition of ZnS and Zn-Met in the basal diet,but the soft broken egg rate in the Zn-Met group was decreased by 78.95%compared with that in the ZnS group(P>0.05).In conclusion,compared with ZnS,dietary Zn-Met supplementation can promote the deposition of Zn in liver and eggshell gland during the late laying period,and then improve the CA activities of liver and eggshell gland,so as to promote eggshell calcium deposition,resulting in the increase of eggshell thickness and eggshell strength,and ultimately reduce the rate of soft broken eggs.