Effect Of Tea Polyphenols And Selenium Yeast On Yolk Cholesterol, Selenium Content And Antioxidant Activity In Hens

This study, experimental design of two factors and three levels, was to explore the effect of tea polyphenols and selenium yeast which were added to the basal diets on the performance, egg quality, cholesterol content and selenium content in yolk, and antioxidant activity in serum of laying hens. Then selected and confirmed the appropriate addition and combination of polyphenols and selenium yeast in basal diets, to provide the scientific evidences for poultry farming and production of low-cholesterol and selenium-enriched eggs with tea polyphenols and selenium yeast. A total of810healthy44-week-old green shell laying hens were obtained and randomly divided into9treatments, with5replicates of18each, pre-test period for7days, the positive test for28days. The basal diets supplemented with different doses of tea polyphenols and selenium yeast as test diets, the tea polyphenols set to three levels of0,200,400mg/kg, selenium yeas (metered by Se) set to three levels of0,0.25,0.5mg/kg. The results showed that:(1) The addition of tea polyphenols and selenium yeast to diets made an increased trend of average egg weight (P>0.05), added200,400mg/kg tea polyphenols could be significantly improved laying rate (P<0.05) and reduce feed/egg ratio (P<0.05), the interaction between the two on production performance made no significant difference (P>0.05).(2) There were some increased trends of egg yolk index, yolk colour and Haugh unit by the diets supplemented with tea polyphenols and selenium yeast (P>0.05), added0.5mg/kg selenium yeast significantly improved the egg shape index (P<0.05), and eggshell thickness decreased significantly (P<0.05), added200,400mg/kg tea polyphenols significantly slowed down the decreased of Haugh unit during storage (P<0.01), the interaction between the two had no significant effect on egg quality (P>0.05).(3) Diets supplemented with200,400mg/kg tea polyphenols significantly reduced yolk cholesterol level (P<0.01), supplemented with0.25,0.5mg/kg yeast selenium could be able to significantly improve yolk selenium content (P<0.01), the effects of interaction between the two were not significant both on yolk cholesterol and selenium content (P>0.05).(4) Added200,400mg/kg tea polyphenols to diets significantly enhanced the serum T-SOD activity (P<0.01) and T-AOC (P<0.05), and the increase of GSH-Px activity was a trend (P>0.05), added400mg/kg tea polyphenols could significantly reduce MDA content (P<0.01), added0.25,0.5mg/kg selenium yeast significantly improved serum GSH-Px activity (P<0.01), T-AOC (P<0.01) and significantly reduced MDA content (P<0.01), and the trend of T-SOD activity was increased (P>0.05), the enhancement of antioxidant capacity in hens’ serum was significantly affected by the interaction between the two (P<0.01or P<0.05).It is concluded that the basal diet supplemented with400mg/kg tea polyphenols and0.25mg/kg selenium yeast doesn’t make an antagonism effects on production performance and egg quality, allowing the efficient production of selenium-rich and cholesterol-low green shell eggs, making a synergy effect on the improvement of antioxidant activity of hens.