Effects Of Betaine On Growth Performance And Carcass Quality Of Fattening Ningxiang Pigs

Sixteen 45 kg Ningxiang pigs were randomly divided into 2 groups with 4 replicates in each groups and 2 pigs in each replicates.The diet of control group was a basal diet,while the diets of test group were supplemented with 0.2% betaine in the basal diet.The trial period was 81 days.The aim of this study was to investigate the effects of betaine on growth performance and carcass quality of fattening Ningxiang pigs.The test results show that:(1)Growth performance: Adding betaine to diet had no significant effect on the daily gain,feed intake and the ratio of feed to gain in fattening Ningxiang pigs.(P > 0.05).(2)Carcass performance: The ratio of the back mark thickness and the fat in test group were reduced significantly(P < 0.05).The ratio of the lean meat of fattening Ningxiang pigs in test group was increased significantly(P < 0.05).The drip loss,water loss,cooking loss and shear strength of fattening Ningxiang pigs in test group was reduced significantly(P <0.05).There was no significant effect on slaughter performance,leaf fat coefficient,skin thickness and the ratio of skin and bone(P > 0.05).The b value of Ningxiang pork at 24 h was significantly reduced(P < 0.05),while the other meat color index was not significantly different(P > 0.05).The p H of the back muscle and biceps femoris was not significantly different(P > 0.05).(3)Biochemical index: The level of blood glucose of fattening Ningxiang pigs was reduced significantly(P < 0.01).The content of serum lipase of fattening Ningxiang pigs was increased significantly(P < 0.01).The the level of TC in liver of fattening Ningxiang pigs in test group was significantly reduced(P < 0.01).And there was no significant effect on the contents of TG,TC,LDL-C,HDL-C and BUN in serum,and the contents of TG,TP and LDL-C in liver(P > 0.05).(4)Conventional nutrients of muscle and liver: The dietary betaine significantly decreased the crude fat content in the biceps femoris as well as the crude fat and total water content in the liver(P < 0.05).There was no significant effect on the content of total water and EE in the longest dorsal muscle,and the content of total water in biceps femoris(P >0.05).(5)Digestibility and digestive enzyme activity: The addition of betaine in the diet significantly improved the digestibility of EE in fattening Ningxiang pigs(P < 0.05).But there was no significant effect on the digestibility of total energy,ash and dry matter(P >0.05).There was no significant difference in amylase,protease and lipase between the two groups(P > 0.05).(6)Intestinal immune factor: The addition of betaine significantly reduced the content of IL-8 and IL-8 in fattening Ningxiang pigs(P < 0.05),and increase the content of SIg A(P< 0.05).There was no significant difference in TNF and IL-6(P > 0.05).(7)Intestinal volatile fatty acids: There was no significant difference in the contents of acetic acid,propionic acid,isobutyric acid,butyric acid,isovaleric acid,valeric acid and total acid in the intestinal tract of the fatting Ningxiang pig between the two groups(P > 0.05).(8)Colonic microorganism: There was no significant difference in the biological diversity and species richness of the colonic microorganism in the fatting Ningxiang pig between the two groups(P > 0.05).The similarity of microbial community composition in betaine group was higher than that in control group.There was no significant difference in the dominant bacteria between the two groups in the level of genus and phylum(P > 0.05).At the level of genus,there were significant differences between the two groups(P > 0.05).The difference bacteria were: Lachnoclostridium,Eubacterium,Roseburia,Lachnospiraceae-UCG007 and Romboutsia in betaine group.The difference bacteria in the control group were: Erysipelototrichaeae,Prevotella,Candidatus and Lachnospiraceae-FCS020.(9)Genes related to fat metabolism: The addition of betaine significantly improved the expression of FABP4 m RNA in the longissimus dorsi muscle of Ningxiang pig(P < 0.05).The m RNA expression of ATGL,PPAR γ and SIRT1 in the subcutaneous fat of the back of Ningxiang pig was increased significantly(P < 0.01).The m RNA expression of Fas and FABP3 was decreased significantly(P < 0.01)in the subcutaneous fat of the back.There was no significant effect in the expression of FABP3,ACC,Fas,LPL,FATP1,PPAR γ and ATGL in the longissimus dorsi muscle,and no significant difference in the expression of ACC,FABP4,LPL and FATP1 in the subcutaneous fat of back(P > 0.05).