Effects Of Detary Iulin On Gowth Prformance,Serum Parameters,Cecal Microflora And Metabolite Of Weaned Rabbits

The purpose of this experiment was to study the effects of adding inulin on the growth performance,serum parameter,cecal microflora and metabolite of weaned rabbits,in order to provide a theoretical basis for the application of inulin in meat rabbit production.The main results of this study are as follows:In this experiment,a total of 192 healthy 35-day-old weaned Iraa rabbits were used randomly allocated to 4 groups(control group and 3 inulin groups).There are 48 rabbits in each group.Four rabbits in a page was regarded as a repilcate and each group had 12 replicates.In control group(CON group),rabbits were fed a basal diet,and in inulin group rabbits were fed experimental diets containing 1%,1.5% and 2% inulin,respectively(named IN1 group、IN1.5 group and IN2 group).The pre-trial period was 7days and the formal feeding period was 28 days.The results showed as follows :(1)Compared with CON group,the growth performances,such as final weight,ADG,ADFI and F/G were not significantly different among IN1 group,IN1.5 group and IN2 group(P > 0.05).(2)Compared with the CON group,the serum T-AOC levels of inulin groups tended to increase(P > 0.05).Compared with the CON group and IN1 group,the activities of serum GSH-Px and SOD were significantly increased in IN1.5 group and IN2 groups(P < 0.05),and there was no significant difference in serum MDA content among all groups,but it showed a reduced trend with the increase of inulin supplemental level(P > 0.05).(3)Compared with CON group,the serum Ig A,Ig G and Ig M contents of IN1 group were increased,but the difference was not significant(P > 0.05).The serum Ig A、Ig G and Ig M levels were significantly increased in IN1.5 group and IN2 group(P < 0.05).There was no significant difference between IN1.5 group and In2 group(P > 0.05).(4)Compared with the CON group,the serum TNF-α and IL-1β contents were not significantly difference in IN1 group(P > 0.05),the serum TNF-α level of IN1.5 group was increased but the difference was not significant(P > 0.05),the contents of TNF-α and IL-1β in IN2 group were significantly increased(P < 0.05).The serum IL-10 in IN1 group and IN2 group was significantly decreased(P < 0.05),IL-10 content was reduced in IN1.5 group but the difference was not significant(P > 0.05).(5)Alpha diversity analysis showed that compared with the CON group,cecal microbiota diversity of IN1 group and IN1.5 group were not significantly different(P > 0.05).Simpson and Shannon indexes of cecal microorganism were significantly reduced in IN2 group(P <0.05)and cecal microbial diversity was decreased significantly.At the phylum level,Firmicutes,Bcteroidetes,Verrucomicrobia and Proteobacteria were the dominant bacteria in the cecal microflora of weaned rabbits.In IN1 and IN2 group,the relative abundance of Firmicutes in cecum was reduced(P > 0.05),the relative abundance of Verrucomicrobia in inulin groups was increased(P < 0.05),the relative abundance of Proteobacteria showed a decreasing trend with the increase of inulin supplemental level(P > 0.05),and the abundance of Bacteroidetes in IN2 group was increased(P > 0.05).At the family level,the relative abundance of Rhizobacteriaceae and Ackeramniaceae in IN2 group was significantly increased(P < 0.05),while the abundance of Ruminococcaceae in IN1 and IN2 groups had a decreasing tendency(P = 0.083).At the genus level,with the increase of inulin supplemental level,the relative abundance of Ackermanniae increased gradually,while Christensenellacea was decreased(P < 0.05).(6)Caecum contents metabolomic analysis results show that compared with the CON group,in IN1 group,the relative concentrations of creatine,uric acid,lactic acid and other metabolites were reduced significantly(P < 0.05).The difference metabolites mainly affected arginine and proline metabolism,pyruvate metabolism pathway and gluconlysis pathway through pathway analysis.In IN1.5 group,the contents of different metabolites including creatine,choline and palmitoleic acid,were significantly reduced(P < 0.05),which affected the metabolism pathway including phosphatidylethanolamine biosynthesis,tryptophan metabolism,phosphatidylcholine biosynthesis and pyruvate metabolism.The relative concentrations of different metabolites in IN2 group,including4-pyridoxic acid,citric acid and indole-3-carboxylic acid,were significantly decreased(P < 0.05),which mainly affected the metabolism of tryptophan metabolism,synthesis and degradation of ketone bodies and vitamin B6 metabolism.In summary,Dietary inulin had no significant effect on performance of meat rabbits,but increased serum antioxidant capacity,increased immune function,improved cecal microflora structure,regulated the production of metabolites,,and maintained intestinal health.