| Chickens with colibacillosis is one of the bacterial diseases that have brought great economic losses to poultry industry.The use of traditional antibiotics for preventing and controlng Escherichia coli has the side effects of increasing drug resistance of E.coli and prolonging its withdrawal period.Therefore,it is necessary to find another safe and harmless treatment.Pomegranate peel,as a traditional Chinese medicine,is rich in bioactive substances,and can deal with bacterial and oxidant.Fermentation technology can increase the concentration of its active ingredients.At present,the main source of pomegranate peel is discarded fruit dregs from large fruit juice factories.It’s cheap,has a low secondary utilization rate and is easy to promote.Thus,this experiment was conducted to investigate the different effects of fermented pomegranate peel and unfermented pomegranate peel on growth performance,intestinal morphology and intestinal microflora of broilers,and their protective effects on broilers infected by Avian pathogenic E.coli.It provided theoretical basis for the use of fermented pomegranate peel in broiler breeding.A total of 240 one-day-old 817 broilers were divided into 6 groups with 5 replicates per group and 8 broilers per replicate.The experiment period was 28 d.The six groups were as follows:non-infected control group(group A),non-infected fermented pomegranate peel group(group B),non-infected unfermented pomegranate peel group(group C),infected control group(group D),infected fermented pomegranate peel group(group E)and infected unfermented pomegranate peel group(group F).Both fermented and unfermented pomegranate peel were added to the basal diet at 0.2%.The infection method was as follows:Groups A,B and C were orally gavaged with 1 m L normal saline every day in the infection stage,and groups D,E and F were orally gavaged with 1 m L avian pathogenic E.coli liquid with a concentration of 5×10~8CFU/m L every day in the infection stage.Growth performance:The average body weight of group B was significantly higher than that of group A and C(P<0.05).The feed-to-weight ratio of groups B and C was lower than that of group A;After 28 days of infection,the average body weight of group F was significantly higher than that of group D and E(P<0.01).The average body weight of group E was significantly higher than that of group D(P<0.05).The feed-to-weight ratio of groups E and F was lower than that in group D.When E.coli was infected,the death rate in the infected group was about 20 percent.The results showed that fermented pomegranate peel could increase average body weight,decrease feed-to-weight and increase feed utilization rate of broilers.Unfermented pomegranate peel had positive effects on the stability of growth performance of broilers infected with E.coli.Both fermented and unfermented pomegranate peel could not reduce the mortality of broilers.Serum indexes:The TP and GLO content in group D was significantly higher than them in group E and F(P<0.05),and it significantly increased compared with group A(P<0.01);The AKP content in group B was 14.17%higher than it in group A(P<0.05);Compared with group E,the content of ALT in group D and group F was significantly increased by 33.33%and 34.76%(P<0.05).There was no significant difference in alanine aminotransferase between group E and group B(P>0.05).Compared with group A,CAT in groups B and C increased by 82.98%and51.02%(P<0.01),the content of MDA in groups A and C was significantly different from that in groups D and F(P<0.05).There was no significant difference between group B and group E(P>0.05).The T-AOC of group C was significantly different from that of other groups(P<0.05).The results showed that the fermented pomegranate peel had a good protective effect on liver tissue.It reduced cell membrane damage caused by MDA and promoted anti-oxidation and immune function,but the effect was not significant(P>0.05);Unfermented pomegranate peel can effectively improve the total antioxidant capacity of broilers.Histological structure:Ratio of villus height to crypt depth(VH/CD)of duodenum and jejunum in group B and C was significantly higher than that in group A(P<0.01).The ileum VH/CD ratio was significantly higher than that of group A(P<0.05).The bacterial load in the heart was lower than that in the liver.The difference between groups A,B,C and D,E,F was very significant(P<0.01).The bacterial load of heart and liver in group D was 4 times higher than that in group E and 2-3 times higher than that of F group(P<0.01).The results showed that the model of E.coli infection was successfully established.The villus height and VH/CD ratio of small intestine were increased and crypt depth of small intestine was decreased by adding 0.2%fermented pomegranate peel in basal diet.The effect on duodenum and jejunum was stronger than that on ileum.Fermented pomegranate peel had inhibitory effect on the intestinal colonization of avian pathogenic E.coli and unfermented pomegranate peel had better protective effect on intestinal structure than fermented pomegranate peel.Intestinal flora changes:Infection with E.coli and addition of 0.2%fermented pomegranate peel had certain effects on intestinal flora diversity.Groups D,E,F with Groups A,B,C between intestinal flora species difference is bigger.Groups B,E and C,F differences between flora than between groups A and D.Group F intestinal flora highest abundance;The relative proportion of Bacteroides in groups A,B and C was significantly higher than that in groups D,E and F(P<0.05).The relative proportion of Bacteroides in group B was the highest,which was significantly different from that in groups A and C(P<0.01).The relative proportion of Alistipes in group A and D was significantly higher than that in group B,C,E and F.(P<0.01).The results showed that fermented pomegranate peel could effectively increase the relative abundance of Bacteroidetes in the intestinal tract,while unfermented pomegranate peel could effectively improve the diversity of intestinal flora.Both of them had a very significant effect on reducing the content of intestinal Alistipes(P<0.01).It can better protect the intestinal stability when intestinal flora is damaged and help it to restore dynamic balance faster.Pomegranate peel could increase average body weight,svillus height and VH/CD ratio of small intestine of broiler.It can decrease feed to meat ratio and crypt depth of small intestine.It increase relative abundance of Bacteroidetes and decrease the content of Alistipes in intestinal tract.The effect of fermented pomegranate peel was significantly better than that of unfermented pomegranate peel(P<0.05).In chicken colibacillosis,pomegranate peel can not reduce mortality,but it can effectively alleviate chronic inflammation,protect heart,liver and intestinal morphology.It can also redeem the loss of average body weight and average daily gain due to disease. |
