Effects Of Dietary Selenium And Vitamin E On Reproduction And GPX Gene Expression In Boer Goats

Selenium(Se)has the function of anti-oxidation,enhancing immunity,participating in hormone metabolism,antagonizing toxic metal elements and anticancer.And Vitamin E(VE)has the function of antioxidant,immune promotion and fertility maintenance.There some synergistic effects between SE and VE.In this paper,five different experiments were conducted to evaluate the effects of selenium and vitamin E on nutrient digestibility,production performance,reproductive performance,immunity and the expression of GPX gene mRNA from goat(copra hircas). In the first part of the experiment,56 goats were selected and randomly divided into 7 treatment groups(n=8)with similar birth date and weight by the 3×2+1 factorial arrangement.The selenium(nano SE)was divided into three levels(0.1,0.2, 0.3 mg/kg)and vitamin E was divided into two levels(100 and 200 IU/kg)for studying the effect of different doses of selenium and vitamin E on the apparent digestibility of nutrients in the diet,which will provide the scientifie basis for selenium and vitamin E in goat production.The second part is about the effect of dietary selenium and vitamin E on reproductive performance of goats.Selenium and vitamin E have an important influence on the reproductive performance.In this part of the experiment,selenium and VE were added was the same as the first part.The effects of seleniun and vitamin E on the reproductive performance of animals is a hot issue in the cross study of nutrition science and reproductive science.The effects of selenium and vitamin E supplementation on reproduction,reproductive hormones and reproductive diseases in goats were studied. The third part of the experiment studies the effects of selenium and vitamin E supplementation on growth and immunity of newborn lambs.Goats were randomly divided into 7 treatment groups(n=8)with a factor of 3x2+1-Selenium three levels (0.1,0.2,0.3 mg/kg),VE levels(100 and 200 IU/kg),to study the effect of the growth and immune.The fourth part is researching the content of dietary selenium and vitamin E on antioxidant enzyme activity and semen quality of lambs.Lambs were randomly divided into 7 treatment groups(n=8)with a factor of 3×2+1.Selenium three levels (0.2,0.3,0,4 mg/kg),VE two levels(100 and 200 IU/kg),to study the effect of dietary selenium and VE on antioxidant enzyme activity and semen quality of lamb.The fifth part of the study is about the effect of dietary supplementation of selenium and VE on the expression of GPX gene mRNA in goat tissue.From the results,we can get the following conclusions:1.The addition of nano seleniun and VE to the diet of female goats had a certain effect on the feed intake.The difference of neutral detergent fiber(NDF)and acid detergent fiber(ADF)intake between the G3 and G4 group of female goats was significant.The dry matter and crude fat in feces of the G3 and G4 group female goats was reduced by adding selenium and VE to the female goats diets.The addition of selenium and VE decreased the content of nutrients in the other groups,but did not reach the significant level.The effects of different levels of selenium and VE on the apparent digestibility of nutrients in different groups were different.The crude protein and crude fat apparent digestibility did not reach significant level.The results showed that the addition of nano selenium and VE can promote the digestibility of feed.2.The effects of selenium and VE on the concentration of serum reproductive hormone and thyroid hormone in pregnant ewes were related to the type of hormone,gestation period and dosage.The addition of selenium and VE significantly affected the reproductive hormones in serum of the female goats.Selenium and VE levels on the goat gestation 120 d,G1,G2,G3,and G5 group of sheep serum follicle stimulating hormone(FSH)concentration was significantly higher than the control group(P<0.05);the 30d and 60d pregnant ewes and 90 d serum estradiol(E2)concentration significantly(P<0.05);Goat serum progesterone(P)concentration significantly affected pregnancy(P<0.05).Serum thyroxine(T4)levels were significantly affected by 120 d(P<0.05).Selenium and VE levels on goat pregnancy free iodine thyroid three original amino acids 30d and 60d in serum(FT3)were significantly affected in pregnant goats of 30d;Selenium and VE levels affected serum free thyroxine(FT4)concentration in the pregnant goats with 90 d(P<0.05).3.Dietary selenium and VE can promote the growth and immune function of newborn lambs.The test group goats colostrum selenium content were much higher than the control group GO(P<0.05);experimental group of newborn lamb VE after birth and the content of selenium in serum of 12h were much higher than those in control group(P<0.05);IgG and IgM were much higher than those in control group(P<0,05);to 30 days of age in the lamb,lamb weight in experimental group were significantly higher than that of the control group(P<0.05);average daily gain was significantly higher than the control group(P<0.05);group G3,G4 and G6 on the growth of lamb average body length was significantly higher than the control group(P<0.05);the lamb body height in experimental group were significantly higher than the control group(P<0.05),the G3 group lamb body high maximum test group;average day length weight of lamb was significantly higher than the control group(P<0.05);lamb chest test group were significantly higher than control group(P<0.05),the G3 group of experimental group lamb bust;bust growth was significantly higher than the control group(P<0.05),the G3 group had the highest daily gain;the experimental group was born lamb number higher than that of control group.The mortality rate was lower than the control group.There was no dead lamb.4.Dietary selenium and VE can improve the quality and antioxidant enzyme activity of male lambs.Feeding Selenium and VE can significantly reduce the rate of sperm deformity(P<0.05).Dietary supplementation of selenium and VE group sperm acrosome integrity rate were much higher than control group(P<0.05),G1 group of sperm acrosome integrity rate than the control group increased,but did not reach significant level(P>0.05);Selenium and VE supplementation can significantly increase the seminal plasma glutathione peroxidase(GSH-Px)the activity and total antioxidant capacity(T-AOC)(P<0.01).The activities of superoxide dismutase(SOD)and catalase(CAT)in the seminal plasma of the control group were much lower than those of the other groups(P<0.05).The concentration of malondialdehyde(MDA)was much higher than that of fed group(P<0.05).5.The expressions of GPX-1,GPX-2,GPX-3,and GPX-4 gene mRNA in the heart,liver,spleen,lungs,kidneys and testis of goats were expressed in different degrees.The addition of trace element selenium promotes the expressions of GPX-1,GPX-2,GPX-3,and GPX-4 gene mRNA.The expressions of GPX-1,GPX-2,GPX-3,and GPX-4 gene mRNA in each tissue reached the highest when the dosage of selenium was 0.3 mg/kg and the amount of VE was 100 IU/kg.It was found that Selenium and VE in the diet of goats could improve the digestibility of nutrients and production performance of goats.The effects of Selenium and VE on gene expression in goat tissues were studied through the growth of offspring lambs,immune function、antioxidant properties and modem molecular biological ways,and it build the foundation for researching the mechanism of selenium and VE on goats.