Effects Of Dietary Supplementation Of Enterobacteriaceae On Growth,Intestinal Development And Intestinal Microflora Of Weaned Piglets

With the rapid development of domestic pig industry,the pork is rich in protein and nutrients,which has become one of the main sources of meat food in people’s daily life.However,the pig industry has been facing the test of disease.Because adding antibiotics in the feed can improve the growth performance of piglets and reduce the occurrence of diseases,antibiotics have been used in the feed of weaned piglets.However,antibiotics added to feed will lead to drug resistance,residue problems and intestinal flora imbalance,which is harmful to animal health.According to the announcement of the Ministry of Agriculture and Rural Affairs of China,starting from July 1,2020,it will not be allowed to add growth-promoting drug feed additives(except Chinese herbal medicine)to commercial feed.Enterobacteriaceae is a kind of antimicrobial peptides,which has attracted extensive attention at home and abroad because of its strong antibacterial ability,promoting animal growth and improving intestinal health.As a feed additive,Enterobacteriaceae has a broad development prospect in the aquaculture industry.Therefore,in this study,antimicrobial peptides(Enterobacteriaceae)and antibiotics(Colistin sulfate,Olaquindox)were were added into the weaned piglets diet.To study the application of Enterobacteriaceae on growth and intestinal microflora of weaned piglets.Experiment 1: Effects of dietary supplementation of Enterobacteriaceae instead of Colistin sulfate on growth,intestinal development and caecal microflora of weaned pigletsA total of 108 healthy DLY weanling piglets(weaned at day 28)with an initial average body weight of(8.5 ± 0.5)kg were allocated to 3 treatments with 6 replicates per treatment and 6 pigs per pen with randomized complete block design,with the respective treatments being basal diet(control group),basal diet + 150 mg/kg Colistin sulfate(Colistin sulfate group),basal diet + 2.5 mg/kg Enterobacteriaceae(Enterobacteriaceae group).The results showed that:(1)Compared with the control group,the ADG and ADFI of Enterobacteriaceae group and Colistin sulfate group were significantly increased(P < 0.05);the number of death both in Enterobacteriaceae group and Colistin sulfate group was significantly decreased(P < 0.05).(2)Compared with control group,the number of Escherichia coli in cecum was significantly reduced by adding Enterobacteriaceae(P <0.05).(3)In duodenum,villus height and crypt depth of Enterobacteriaceae group and Colistin sulfate group were significantly higher than those of control group(P < 0.05);in jejunum,villus height and crypt depth of Enterobacteriaceae group were significantly higher than those of control group(P < 0.05);in ileum,villus height and crypt depth of Enterobacteriaceae group were significantly higher than those of Colistin sulfate group.Compared with Colistin sulfate group,villus height and villus height recess depth in control group were significantly higher(P < 0.05).The results showed that 2.5 mg/kg Enterobacteriaceae and 150 mg/kg Colistin sulfate could increase the average daily gain,reduce the number of dead piglets,improve the growth performance of piglets,intestinal development,and reduce the number of Escherichia coli in cecum.Experiment 2: Effects of dietary supplementation of Enterobacteriaceae instead of Olaquindox on growth and caecal microflora of weaned pigletsA total of 216 healthy DLY weanling piglets(weaned at day 24)with an initial average body weight of(7.0 ± 0.5)kg were allocated to 3 treatments with 4 replicates per treatment and 18 pigs per pen with randomized complete block design,with the respective treatments being basal diet(control group),basal diet + 100 mg/kg Olaquindox(Olaquindox group),basal diet + 1.5 mg/kg Enterobacteriaceae(Enterobacteriaceae group).The results showed that:(1)Compared with the control group,the final weight,ADG of piglets in Olaquindox group and Enterobacteriaceae group were significantly increased(P< 0.05);no piglets died during the whole experimental period.(2)The number of Escherichia coli in Olaquindox group was significantly lower than that in control group(P< 0.05),and the number of Escherichia coli in Enterobacteriaceae group was significantly lower than that in control group and quindox group(P < 0.05).The results showed that 1.5mg/kg Enterobacteriaceae and 100 mg/kg Olaquindox could both increase the daily gain and reduce the number of Escherichia coli in cecum of piglets.