| Antibiotics have produced large side effects in breeding and production,which severely inhibited the development of our country’s animal husbandry.For this reason,it is necessary to develop a new type of"green,safe and efficient"feed additives,and probiotics are practicable choice for it.Lactobacillus Plantarum,as a leader in probiotics,having the advantages of acid resistance,high pressure resistance,and high viable counts,is an ideal substitution.Order to verify the specific effects of Lactobacillus plantarum LP-37 as a feed additive in different animal breeding and production,Lactobacillus plantarum LP-37 was added to the feed to feed AA broilers and Nile tilapia,and test the two Effects of animal growth and immune performance in different growth environments.This research is mainly divided into the following two parts:(1)Add Lactobacillus plantarum LP-37 to AA broiler feed for 21 days to determine the growth index,slaughter index,meat quality and color,immune organ index,intestinal tissue morphology,digestive enzyme activity and immune-related gene expression changes in broiler chickens.The experiment was divided into three groups:A0,B1 and B2.A0 was the control group fed with basic homemade feed,and the B1 and B2 groups were fed with 1×10~7CFU/g and 1×10~8CFU/g Lactobacillus plantarum LP-37,respectively.The self-made feed has six repetitions in each group and 16 chickens in each repetition.The results showed that in terms of growth indicators,the B1 and B2 groups increased the average body weight and average feed intake,and decreased the feed-to-weight ratio compared with the control group.There was an upward trend but the difference was not significant(P>0.05);In terms of slaughter indicators,Compared with the control group,the B1 and B2 groups had no significant differences in the half evisceration rate,full evisceration rate,leg muscle rate,pectoral muscle rate and abdominal fat rate(P>0.05);There was no significant difference in flesh color(P>0.05);In terms of immune organ index,compared with the control group,the bursa index of B1 group was significantly increased(P<0.05),and the thymus index,spleen index and bursa index of B2 group were significantly increased(P<0.05);In terms of intestinal tissue morphology,compared with the control group,the B1 group significantly increased the duodenum,jejunum,and ileum villi to tones ratio and the duodenal villi length(P<0.05),and the B2 group significantly increased by 12 the length of the villi of the duodenum and jejunum(P<0.05),significantly increased the villus-to-crypto ratio of the duodenum and jejunum(P<0.01).There was no damage to the intestinal villi of the B1 and B2 groups;In terms of digestive enzyme activity,the B1 group Compared with the control group,the activity ofα-amylase in the ileum and jejunum increased,but not significantly(P>0.05).The activity ofα-amylase in the jejunum and ileum of group B2 increased significantly(P<0.05);It was detected by qtr.-PCR the expression of immune-related genes,compared with the control group,the expression of IFN-γand IL-1βgenes in the B1 and B2groups was significantly up-regulated(P<0.05).(2)Add Lactobacillus plantarum LP-37 to Nile tilapia feed for 60 days,and determine the changes in Nile tilapia growth indicators,intestinal tissue morphology,digestive enzyme activity and immune-related gene expression.The test is divided into 4 groups:C0,L1,L2,and L3.C0 was the control group fed with basic feed,L1,L2 and L3 were fed with feed supplemented with 1×10~6 CFU/g,1×10~7 CFU/g and 1×10~8 CFU/g Lactobacillus plantarum LP-37,each group 5 replicates,each with 16 fishes.The results showed that in terms of growth indicators,the final body weight of the L1 and L2 groups were higher than the control group,but the difference was not significant(P>0.05),and the final body weight of the L3group was extremely significantly higher than the control group(P<0.01);In terms of tissue morphology,compared with the control group,the L1 group increased the villus length,Implicit ratio and muscle layer thickness,but no significant difference(P>0.05),the L2significantly increased the villus length and muscle layer thickness(P<0.05),and the L3group significantly increased the villus length and down Implicit ratio and muscle layer thickness(P<0.05),the intestinal villi of each test group were not damaged;In terms of digestive enzyme activity,the activities ofα-amylase and alkaline phosphatase in the L1group were improved to a certain extent compared with the control group,But the difference was not significant(P>0.05),theα-amylase activity of the L2 group increased significantly(P<0.05),the alkaline phosphatase activity increased but not significant(P>0.05),theα-starch of the L3 group enzyme activity increased significantly(P<0.01),alkaline phosphatase activity increased significantly(P<0.05);q RT-PCR detected immune-related gene expression,compared with the control group,the expression of IFN-γin the L1,L2,and L3 groups Both were significantly down-regulated(P<0.05),and the expression of IL-1βgene was extremely significantly down-regulated(P<0.01).In summary,it shows that adding Lactobacillus plantarum LP-37 to the feed can improve the growth performance and digestive enzyme activity of AA broilers and Nile tilapia to a certain extent,improve the morphology of intestinal tissues,and up-regulate the IFN-γand IL-1βgenes of AA broilers,the expression of Nile tilapia down-regulated the expression of IFN-γand IL-1βgenes,which verified the role of Lactobacillus plantarum LP-37 in the production of AA broilers and Nile tilapia. |
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