Influence Of Selenium Yeast And Polysavone On Antioxidant Ability And Cholesterol Metabolism In Laying Hens

In recent years, it has been recognized that the selenium closely related to healthy of humans and animals. And it has been a research hotspots that how to increase the body’s intake content of selenium through increasing the selenium content of food. Eggs as the important part of human foods are rich in nutrients such like protein. Therefore, it is positive to body’s ability of antioxidant and immunity by increasing selenium content of eggs. However, eggs can not apply to hyperlipidemia patients, because the cholesterol content of eggs is too large. Polysavone can significantly effect the body’s lipid metabolism. This study explore the effection of dietary added selenium yeast and polysavone to production performance, egg quality, antioxidant ability and lipid metabolism of laying hens.1296 69-week old Hyline Brown hens were randomly allocated into 12 groups with 6 replicates of 18 hens in each. Using 3×4 factorial design, the basal diet supplementeded with different levels of selenium yeast (0,0.2、0.6、1.0mg/kg) and polysavone (0、500、1000mg/kg) respectively. Feeding hens basal diet in pre-feed period(2 weeks), and the experiment lasted for 8 weeks. After the feeding experiment, measure the index of production performance, egg quality, antioxidation ability and lipid metabolism. The results were as follows:1.The diet supplemented with selenium yeast, polysavone, interaction between them could significantly increase the laying rate, reduce feed/egg ratio(P<0.05). And the influence to egg weight and daily feed intake is not significant(.P>0.05). The group of hens intake the diet supplementeded with 0.6 mg/kg selenium yeast and 1000 mg/kg polysavone represent the highest laying rate and the lowest feed/egg ratio.2.The diet supplemented with selenium yeast, polysavone, interaction between them has no significant influence on egg albumen height, egg shape index, yolk color and thickness of egg shell, and has the trend to increase Haugh unit and egg shell strength(P>0.05). The diet supplementeded with 0.6 mg/kg selenium yeast and 500 mg/kg polysavone can significantly increase the Haugh unit and the shell strength of egg(P<0.05). The diet supplementeded with 0.6 mg/kg selenium yeast and 1000 mg/kg polysavone can significantly increase the egg shell strength(P<0.05).3.The diet supplementeded with selenium could significantly improve activity of GSH-Px, T-SOD, T-AOC in blood, GSH-Px in liver,GPX-I mRNA expression in liver(P<0.01),and could reduce the content of MDA in blood. The diet supplementeded polysavone could significantly improve GSH-Px, T-SOD, T-AOC in blood, GSH-Px in liver,TR1 mRNA expression in liver(P<0.01), and has the trend of reducing content of MDA in blood and increasing the GPX-1 mRNA expression in liver, the difference was not significant(P>0.05). The diet supplementeded with interaction between selenium yeast and polysavone could significantly improve the activity of GSH-Px, T-SOD in blood, GSH-Px in liver, and the expression of GPX1, TR1 in liver. It could also raise the activity of T-AOC(P<0.01), reduce content of MDA in blood, but the difference was not significant(P>0.05). The activity of GSH-Px, T-AOC, T-SOD in blood,GSH-Px in liver, and the mRNA expression of GPX1 and TR1 in liver of the hens in the group that intake the diet supplementeded with 0.6 mg/kg selenium yeast and 1000 mg/kg polysavone was higher than the other groups, and the content of MDA in blood was lower than the other groups. The difference between this group and the control group was significant(P<0.01).4.The diet supplementeded with selenium yeast could significantly reduce the content of cholesterol and triglyceride in liver, reduce the mRNA expression of HMGCR, and increase the mRNA expression of SREBP-1c in liver(P<0.01). The diet supplementeded with polysavone could significantly reduce the content of cholesterol and triglyceride, the mRNA expression of HMGCR in liver, and increase the mRNA expression of Cyp7a1 and SREBP-1c in liver(P<0.01). The diet supplementeded with selenium yeast and polysavone could significantly reduce the content of cholesterol and triglyceride, the mRNA expression of HMGCR in liver, increase the mRNA expression of Cyp7a1 and SREBP-1c in liver(.P<0.01). The content of liver cholesterol and triglyceride, the mRNA expression of HMGCR of the hens in the group that intake the diet supplementeded with 0.6 mg/kg selenium yeast and 1000 mg/kg polysavone were lower than the other groups, and the mRNA expression of Cyp7a1 and SREBP-1c in liver is higher than the other groups. The difference between this group and control group is significant(P<0.01).5.The diet supplementeded with selenium yeast could significantly increase the selenium content of yolk(P<0.01).As the dietary selenium yeast level increasing, the selenium content of yolk trended to increase. It has the reducing trend of yolk cholesterol and triglyceride that the hens intake selenium yeast, but the influence was not significant(P>0.05). The diet supplementeded with polysavone could significantly reduce the content of cholesterol and triglyceride of yolk(P<0.01).The cholesterol and triglyceride content in yolk of the hens in the group that intake the diet supplementeded with 0.6 mg/kg selenium yeast and 1000 mg/kg polysavone was lower than the other groups. And it was higher than control group significantly(P<0.01).In summary, it comes the best influence that adding 0.6 mg/kg selenium yeast and 1000 mg/kg polysavone to the diet. And it can effectively increase the selenium content of yolk, reduce the content of cholesterol and triglyceride of yolk, improve the production performance, antioxidant ability, cholesterol metabolism and egg quality.