Effects Of Different Doses Of Bacillus Subtilis On Performance,Egg Quality And Blood Biochemical Indexes Of Laying Hens In Late Laying Stage

In this study,different concentrations of Bacillus subtilis were added in the late laying period of laying hens to explore the optimum amount of Bacillus subtilis in laying hens.4,500 healthy 65-week-old hens in the late-stage laying period were selected,and randomly divided into five groups?each with 3 replicates,300 laying hens per replicate?.Control group?basal diet group?,Bacillus subtilis group I?10⁴cfu/g?,Bacillus subtilis group II?10⁶cfu/g?,Bacillus subtilis group III?10⁸cfu/g?,Bacillus subtilis IV group(10¹⁰cfu/g).The experiment lasted for 60 days.At the 15,30,45 and 60 days,the serum total cholesterol?TC?,total protein?TP?,albumin?Alb?,blood glucose were measured.In addition,the levels of Glucose?Glu?and serum calcium?Ca?and serum phosphorus?P?,and egg quality related indicators?eggshell thickness,eggshell relative weight,egg yolk color and Hastel units?was determined,by calculating production performance and economy Comprehensive evaluation of benefits,to explore the optimal addition amount of Bacillus subtilis in late egg production.The results showed that:?1?Production performance:feeding Bacillus subtilis can significantly improve the feed intake of laying hens,increase the egg production rate,reduce the egg breaking rate,and reduce the death rate.The optimum dosage is 10⁸cfu/g.?2?Analysis of economic benefits:After feeding Bacillus subtilis,the corresponding economic benefits can be improved.During the whole test period,the feed intake is significantly reduced,the feeding amount is significantly reduced,the feeding cost is reduced,and the egg production rate is increased.The income of the eggs is increased,thereby improving the economic efficiency,and the optimum addition amount is 10⁸cfu/g.?3?Egg quality:After 15 days of feeding Bacillus subtilis,the eggshell thickness,eggshell relative weight,egg yolk color and Hastelloy unit?P<0.05?were significantly increased,and there was a certain ratio of calcium to phosphorus in the eggshell.For the adjustment,the optimum addition amount is 10⁸cfu/g.?4?Serum biochemical index:After 15 days of feeding Bacillus subtilis,the albumin,total protein,blood glucose,serum calcium and serum phosphorus levels in the serum of the laying hens were significantly changed?P<0.05?,which significantly lowered the serum cholesterol index.?P<0.05?,and it can be guaranteed that these indicators are in a relatively s Title state,and the optimum addition amount is 10⁸cfu/g.Conclusion:Feeding Bacillus subtilis in laying hens can significantly improve blood index,improve egg quality and increase economic benefits.It can show good effect after 15days of addition,and the optimum dosage is 10⁸cfu/g.