Effects Of Bacillus Subtilis Compound Preparation On Reproductive Performance,serum Index And Fecal Flora Of Xuefeng Black-bone Chicken In The Later Stage Of Egg Laying

In this experiment,the compound preparations of different concentrations of Bacillus subtilis(BS)and essential oils(EO)were added to the diet to study their effects on laying performance,reproductive performance,egg quality,serum indexes and fecal microflora of Xuefeng black-bone chicken,and to explore the effect of their combination and whether they have synergistic effect,so as to provide scientific basis for the application of BS and EO in livestock and poultry production.A total of 576 54-week-old Xuefeng black-bone chicken with similar body weight,healthy and normal diet were randomly divided into 4 groups with 6replicates in each group and 24 hens in each group.The control group(group A)was fed with conventional basal diet,and the experimental group(group B,C and D)was supplemented with 300,600 and 900 mg/kg BS compound preparation,respectively.The pre-trial period is 7 days and the trial period is12 weeks.The results showed that:1)From the first week to the 12 th week of the experiment,when the compound preparation of BS+EO was added to the diet,the egg weight of Xuefeng back-bone chicken tended to increase(P=0.073)and the ratio of feed to egg decreased(P=0.050).2)The hatching rate of fertilized eggs in groups C and D was significantly higher than that in the control group at the 4th week of the experiment(P<0.05);the hatchability of fertilized eggs in group C and D was significantly higher than that in the control group at th e 5th and 8th week(P<0.05);at the 9th and 12 th week of the experiment,the fertilization rate of group B,C and D was significantly higher than that of the control group(P<0.05);From the 1st to 12 th week of the experiment,the fertilization rate of Xuefeng back-bone chicken increased with the addition of BS+EO compound preparation(P=0.094),the hatching rate of fertilized eggs in group C and D was significantly higher than that in the control group(P< 0.05).3)At the end of the 8th week,compared with the control group,the eggshell strength of Xuefeng Black-bone Chicken in group D was significantly higher than that of the control group(P<0.05);and the egg yolk index of Xuefeng Black-bone Chicken could be significantly increased by adding BS+EO compound preparation at the end of the 4th and 8th week and after 30 days of egg storage(P<0.05).4)In the serum antioxidant index,the GSH-Px activity of Xuefeng Black-bone Chicken in group B was significantly higher than that in the control group(P<0.05),and the GSH-Px activity in group D was extremely significantly higher than that in the control group(P<0.01).5)In serum biochemical indicators,the content of TC in the serum of Xuefeng Black-bone Chicken in group D was significantly lower than that in the control group(P<0.05),the content of UA in the serum of Xuefeng Black-bone Chicken in group D was lower than that in the control group(P=0.064).6)In the serum immune index,the content of TNF-α in the serum of Xuefeng Black-bone Chicken in group B,C and D was extremely significantly lower than that in the control group(P<0.01),the content of IL-6 in the serum of Xuefeng Black-bone Chicken in group C and D was extremely significantly lower than that in the control group(P<0.01);the content of AIV-Ab in serum of group B and D was significantly higher than that of the control group(P<0.05).7)In the serum hormone index,compared with the control group,the serum FSH content of Xuefeng back-bone chicken in group C and D was extremely significantly higher than that in the control group(P<0.01),The content of serum E2 in group B,C and D increased extremely significantly(P<0.01),the content of serum LH in group C and D was extremely significantly higher than that in group D(P<0.01),the content of PTH in serum of group B,C and D increased extremely significantly(P<0.01);the content of P in serum of group D increased significantly(P<0.05).8)In the fecal flora index,the content of Escherichia coli in feces of group B and D was significantly lower than that of the control group(P<0.05),the content of Bacillus subtilis in feces of group B,C and D increased extremely significantly(P<0.01).In the detection of fecal samples at the end of the fourth week,compared with the control group(group A),the content of total anaerobic flora in group C was significantly higher than that in the control group(P<0.05),the content of Bacillus subtilis in feces of group B,C and D increased extremely significantly(P<0.01).9)The compound preparation of BS+EO of 900 mg/kg produced the highest economic benefit,which was 5.68% higher than that of the control group.In summary,supplementation the combination diet of BS+EO can improve the laying performance and reproductive performance,the egg quality of eggs,enhance the antioxidant capacity and immune response,and optimize the structure of intestinal flora of Xuefeng black-bone chicken in the later stage of egg laying.