| A trial was conducted to study the influence of Bacillus subtilis additives onlaying performance and egg quality of Hy-Line brown commercial laying hens at lateperiod of laying. A total of480380-day-old layers of Hy-Line Brown with similar eggproduction lever,healthy were randomly divided into2groups with three replicate pergroup and240birds per replicate. Pre-feeding7d, Layering hens which in controlgroup were fed basal diet.The trail group were fed diet supplemented with500mg/kgB.subtilis. The feeding trial lasted for45d. By feeding trail to study the effect ofB.subtilis on the laying performance, serum biochemical parameters,egg quality andultrastructure of eggshell in two groups.On the basis of the above trail, another trialwas carried out to promote B.subtilis. By analysising the impact of B.subtilis onproduction performance,reach a conclusion of its impact on the economic benefits oflaying hens.This study have important practical significance for improving productionperformance,egg quality and economic efficiency of laying hens. The experimentresults were as follows:1B.subtilis significantly improved the production performance of laying hens.There are a significantly differences between two groups,the egg weight of thetreatment group increased by2.62%,the rate of broken eggs decreased by11.69%(P<0.05); Feed intake,feed egg ratio and mortality rate in the test group is lower than thecontrol group (P>0.05); Egg production rate of the treatment group tends to increasecompared to the control group (P>0.05).2B.subtilis significantly improved serum biochemical indicators.The lever of TPand Alb in the treatment group respectively increased by7.76%(P <0.05) and10.15%(P>0.05) than the control group;B.subtilis improved the lever of Glu by27.63%(P<0.01);The lever of TC decreased by8.03%(P <0.05),the calcium content increasedby5.88%(P <0.05) and there is a trend of decreasing of serum phosphorus in the treatment group(P>0.05).3B.subtilis improved egg quality. Eggshell strength in the treatment groupsignificantly increased by16.20%(P <0.05)when compared to the control group.Meanwhile,eggshell thickness, eggshell color, yolk color and Haugh unit in thetreatment group were increased compared to the control group (P>0.05);the relativelyweight of eggshell and shape index did not change significantly (P>0.05); Thecontents of calcium and phosphorus in the eggshell of the two group had no significantdifference (P>0.05).4B.subtilis improved eggshell structure. In the test group,the crack in the outersurface of the shell was finer and more dense,the protruding structure in milk conelayer was more closely;And the treatment group had more nipples,the nipples werenarrower, the structure of the columnar layer and the surface crystal layer was denserthan the control group.5B.subtilis improved the economic efficiency of laying hens, the treatment grouprevenue of0.31yuan per chicken and gross profit improved22.69%compared with thecontrol group.Conclusion: B.subtilis could obviously increase egg weight, reduce egg breakagerate;Feeding B.subtilis significantly improved the content of total protein,bloodglucose and calcium,while,decreased total cholesterol in the serum of layers;FeedingB.subtilis significantly improved eggshell strength,there is no significant differencebetween the content of calcium and phosphorus in eggshell; B.subtilis could improvedeggshell structure,made the shell structure more compact; B.subtilis could improvedthe economic benefits of laying hens. |
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