Effects Of Different Zinc Sources On Growth And Immune Performance Of Pregnant Goats And Offsprings

Xiangdong black goats were selected as the experimental animal for this research.Different zinc sources?zinc sulfate,ZnSO₄,zinc methionine chelate,Zn-Met,zinc glycine chelate,Zn-Gly?were treated 42 days to the pregnant goats before the delivery.The research aimed to select the optimum zinc preparation by detecting the effects of different zinc sources on the production,milk production,immune performance and mineral metabolism indexes of pregnant goats.Growth and immune performance,mineral metabolism indexes and TLR2-MyD88 signaling pathways of offsprings were all measured.The results are as follows:1.Production and milk production performance of pregnant goats:Average daily gain was significantly increased with the feeding of Zn-Met and Zn-Gly during the late gestation of Xiangdong black goats?P<0.05?.The contents of total dry matter,n-hexanoic acid,octanoic acid,monounsaturated fatty acids and polyunsaturated fatty acids in goat milk were also significantly increased with the feeding of Zn-Met?P<0.05?.Moreover,the content of?-linolenic acid was significantly increased with the feeding of Zn-Gly?P<0.05?,but there were not change on amino acid contents sin goat milk with the feeding of Zn-Met and Zn-Gly?P>0.05?.2.Growth performance of offsprings:the birth weight of offsprings were significantly increased with the feeding of Zn-Met and Zn-Gly?P<0.05?.And this advantage of Zn-Gly lasted to 30 days,but it had no effect on the body size of offsprings with the feeding of Zn-Met and Zn-Gly?P>0.05?.3.Immune performance of pregnant goats:The concentrations of IL-6 and IL-8were significantly increase in the blood with the feeding of Zn-Gly?P<0.05?.And the concentrations of IL-22 and lysozyme were also significantly increase with the feeding of Zn-Gly Zn-Met?P<0.05?.However,the activity of AKP and the concentration of CER in the blood of pregnant goats were not changed with the feeding of Zn-Met and Zn-Gly?P>0.05?.4.Immune performance of offsprings:The concentration of IgG was significantly increase in the blood with the feeding of Zn-Gly?P<0.05?.The concentrations of IL-4,IL-6,IL-22 were also significantly increase in the blood with the feeding of Zn-Met on 60 days?P<0.05?.Moreover,the concentration of lysozyme was significantly increased in the blood with the feeding of Zn-Met and Zn-Gly?P<0.05?.However,the activity of AKP and the concentration of CER in the blood of offspring did not changed with the feeding of Zn-Met and Zn-Gly?P>0.05?.5.Mineral metabolism of pregnant goats:the concentration of P was significantly reduced in feces with the feeding of Zn-Met?P<0.05?.And the concentration of K was significantly increased in urinary sediment with the feeding of Zn-Gly?P<0.05?,but the concentrations of Ca and Zn were significantly reduced?P<0.05?.However,the mineral concentrations in the blood did not change with the feeding of Zn-Met and Zn-Gly?P>0.05?.6.Mineral metabolism of offsprings:the concentration of K was significantly increased in the blood on 100 days with the feeding of Zn-Met?P<0.05?.And the concentration of Zn was also significantly increased in the blood and liver on 30 days and 60 days?P<0.05?.However,the concentration of Cu in the blood was significantly decreased on 30 days with the feeding of Zn-Gly?P<0.05?.7.TLR2-MyD88 signaling pathway:The mRNA expression of TLR2 was significantly reduced in the offsprings liver with the feeding of Zn-Met and Zn-Gly?P<0.05?.The mRNA expression of MyD88 in the offsprings liver and the mRNA expression of TLR2 in the offsprings liver were also significantly reduced with the feeding of Zn-Gly?P<0.05?,but the m RNA expression of NFKB1significantly increased in the offsprings liver with the feeding of Zn-Met?P<0.05?.However,the relative expression of TLR2-MyD88 signaling pathway was not change in the offspring lymph nodes with the feeding of Zn-Met and Zn-Gly?P>0.05?.Through all above experiments,it was found that organic zinc supplementation in the late pregnancy of Xiangdong black goat could improve the growth performance of pregnant goats and offsprings and change the quality of goat milk.It could improve the immune performance of offsprings and pregnant goats and increase the zinc deposition in goats liver.This study identified the potential mechanism of the influence of trace element zinc on the growth and immune performance of pregnant goats and their offsprings,and preliminarily explored the corresponding mechanism of different zinc sources in the late pregnancy.