Effects Of‘Kangbao’Fermented Feed On Production Performance,Intestinal Function And Feed Nutrient Digestibility Of Laying Hens During The Late Period

Fermented feed is generally regarded as a green,safe and efficient biological feed.Many studies have shown that fermented feed can improve poultry production performance and immune performance,and has a positive effect on regulating intestinal flora and maintaining intestinal microecological balance.In this experiment,’Kangbao’fermented feed was added to corn-soybean meal basic diet to explore the effects of different levels of fermented feed on production performance,egg quality,intestinal function and feed nutrient digestibility of laying hens in the later stage of laying hens.In order to find the appropriate addition level of fermented feed for laying hens in the later stage of laying,and to provide a reference basis for prolonging laying period and efficient and healthy breeding of laying hens.In this experiment,960 580-day-old Hy-Line Brown Layers with the same environmental conditions in the same henhouse were randomly divided into four groups:group A(control group),group B,group C and group D,adding 0,2%,2.5%and 3%fermented feed to the basic diet respectively.There were 8 repeats in each group,with 30 rats in each group.The pre-trial period was 7 days,and the positive trial period was 42 days.The results show that:(1)The laying rate of each test group is higher than that of the control group,and the laying rate of group C is significantly higher than that of group A(P<0.05),and the ratio of feed to egg in group B and C is significantly lower than that in group A(P<0.05).There is no significant difference in feed-egg ratio and death rate among the three groups(P>0.05).(2)The eggshell weight in the experimental group is significantly higher than that in the control group(P<0.05),and the yolk color in group C is significantly higher than that in group A,group B and group D(P<0.05).The egg weight,eggshell thickness,eggshell strength and Haugh unit in each experimental group are higher than those in the control group,but there is no significant difference in egg protein height and yolk weight among the three groups(P>0.05).(3)The body weight of laying hens in each test group is higher than that in the control group,but there is no significant difference among them(P>0.05).(4)The number of follicles above 2-6 mm,8-12 mm and 12 mm in each experimental group is not significantly different from that in the control group(P>0.05),but the number of follicles in 6-8 mm is significantly higher than that in the control group(P<0.05),and the number in group C is the most.(5)The wall thickness of fallopian tube in each test group is higher than that in the control group,but the difference is not significant(P>0.05).(6)The concentration of serum Ca in group C is significantly higher than that in group A(P<0.05),and there were no significant differences among the test groups and group A on the concentrations of TP,ALB and GLB in serum(P>0.05).(7)The activity of amylase in duodenum and jejunum in test group is significantly higher than that in control group(P<0.05).The activity of chymotrypsin in jejunum and cecum in group C and D is significantly higher than that in group A and B(P<0.05).The activity of jejunal trypsin in test group is significantly higher than that in control group(P<0.05),and the trypsin activity in ileum in group C is significantly higher than that in group A and B(P<0.05).The cecal trypsin activity in group C and D is significantly higher than that in group A and B(P<0.05).(8)The villus length in group C Is significantly longer than that in group A(P<0.05).The depth of duodenal recess in the test group is lower than that in the control group,but the difference is not significant(P>0.05).The duodenal villus concealment ratio and intestinal wall thickness in the test group are higher than those in the control group,but the difference is not significant(P>0.05).There were no significant differences among the test groups and group A on cashmere hidden ratio of jejunum and the thickness of intestinal wall(P>0.05).(9)The contents of crude fat and calcium in chicken feces in group C and D are significantly lower than those in group A(P<0.05),the content of phosphorus in chicken feces in experimental group is significantly lower than that in control group(P<0.05),and the content of crude protein in groups B and C is significantly lower than that in group A(P<0.05).In conclusion,the addition of ’Kangbao’ fermented feed to the diet could improve the production performance of laying hens and egg quality,also promote the growth and development of laying hens’ follicles,body immunity,activity of digestive enzymes in small intestine,tissue structure of duodenum and jejunum,and digestibility of feed nutrients.The appropriate addition of fermented feed in this experiment is 2.5%.