Effects Of Selenium On Production Performance,Serum Biochemical Parameters And Tissue Selenium Content In Laying Hens

Selenium is a necessary trace element for human.It has the functions of anti-cancer and prevention of cataracts,cretinism and Kashin-Beck disease,but China has 2/3 regions lacking selenium.In order to explore ways to produce selenium-enriched poultry,this study filled separately 0.72 μg selenium-enriched yeast and sodium selenite to laying hen(calculated by selenium,the same below),compared their law of absorption;Added 0.00,0.20,0.40,0.60,0.80 mg/kg of selenium-enriched yeast to the diet,explored its effects on production performance,egg selenium content,serum biochemical index and serum selenium content in laying hens;Added separately 0.60 mg/kg of selenium-enriched yeast and sodium selenite to the diet,explored the effect of dietary selenium on tissue selenium content.The study obtained the following results:1.Laying hens had higher absorption efficiency of yeast selenium,yeast selenium` absorption peak was at the 2nd hour,6 hours ahead of sodium selenite,and the absorption level was 33.22% higher(P<0.05),stayed for longer time.2.Yeast selenium had no significant effect on egg weight(P>0.05),0.20 mg/kg of yeast selenium significantly increased egg production rate in laying hens(P<0.05).3.Dietary yeast selenium significantly increased egg selenium content(P<0.05),the content increased with increasing diet selenium levels,selenium enriched in egg yolk mainly.4.Adding yeast selenium(above 0.40 mg/kg)significantly increased serum selenium content in laying hens(P<0.05),and increasesed with increasing added concentration.5.Dietary yeast selenium significantly reduced serum TC levels in laying hens(P<0.05),but no significant effect on serum AST,ALT,ALP,TP,TBIL(P>0.05).6.Both selenium sources significantly increased selenium content in liver,kidney,chest muscle and skin of laying hens(P<0.05),yeast selenium was better than sodium selenite.Yeast selenium significantly increased selenium content in the heart(P<0.05),but sodium selenite has no significant effect(P>0.05).In summary,the addition of 0.60 mg/kg of yeast selenium to the diet had no adverse effect on laying hens during the test period,produced 0.56 mg/kg selenium-enriched eggs,each egg contained selenium 28μg.