低蛋白质饲粮中添加益生菌对育肥猪生长性能、粪便菌群组成和代谢组特征的影响

Effects of Low⁃Protein Diet Supplemented with Probiotics on Growth Performance,Fecal Microbiota Composition and Metabolome Feature of Finishing Pigs

本试验旨在探讨低蛋白质饲粮中添加益生菌对育肥猪生长性能、粪便菌群组成和代谢组特征的影响。选取平均体重为(80.56±0.45)kg的长×大育肥猪90头,随机分为3组,分别为对照组、试验Ⅰ组和试验Ⅱ组,每组3圈(重复),每圈10头(阉公猪与母猪各占1/2)。对照组饲喂含14%蛋白质的常规蛋白质饲粮,试验Ⅰ组饲喂含12%蛋白质的低蛋白质饲粮,试验Ⅱ组饲喂添加益生菌的低蛋白质饲粮(每千克低蛋白质饲粮中含2.0×10^(9)CFU乳酸菌和2.0×108CFU酿酒酵母)。预试期5 d,正试期42 d。结果显示:1)与对照组和试验Ⅰ组相比,试验Ⅱ组的平均日增重显著提高(P<0.05),料重比显著降低(P<0.05)。2)与对照组和试验Ⅱ组相比,试验Ⅰ组粪便中颤螺菌目、毛螺菌目、毛螺菌科、瘤胃球菌科、UCG-005、粪杆菌属、小杆菌属和福涅氏菌属的相对丰度显著降低(P<0.05),解纤维素菌属的相对丰度显著增加(P<0.05);试验Ⅱ组粪便中毛螺菌目、乳杆菌目和毛螺菌科的相对丰度显著高于对照组(P<0.05)。3)试验Ⅰ组与对照组、试验Ⅱ组与对照组以及试验Ⅰ组与试验Ⅱ组粪便样品间分别发现9、37和41种差异代谢物;不同组间差异代谢物的KEGG通路富集分析显示共有27条富集通路;与对照组和试验Ⅰ组相比,试验Ⅱ组粪便中5-羟基吲哚乙酸的表达量显著升高(P<0.05),肾上腺素的表达量显著降低(P<0.05);试验Ⅰ组粪便中N-乙酰-L-苯丙氨酸的表达量显著低于对照组和试验Ⅱ组(P<0.05);试验Ⅱ组粪便中L-谷氨酰胺、D-葡萄糖醛酸的表达量显著高于试验Ⅰ组(P<0.05)。4)与对照组相比,试验Ⅰ组和试验Ⅱ组粪便中总支链脂肪酸、总短链脂肪酸、氨氮和粪臭素含量显著减少(P<0.05);与试验Ⅰ组相比,试验Ⅱ组粪便中乙酸含量显著减少(P<0.05),丁酸含量显著增加(P<0.05)。综上所述,在低蛋白质饲粮中添加益生菌(乳酸菌和酿酒酵母)可改善育肥猪的肠道菌群结构及其代谢物表达,减少粪便中总短链脂肪酸、氨氮和粪臭素含量,提高育肥猪的平均日增重和饲料转化效率。

This experiment was conducted to study the effects of low⁃protein diet supplemented with probiotics on the growth performance,fecal microbiota composition and metabolome feature of finishing pigs.Ninety Landrace×Yorkshire crossbred finishing pigs with an average body weight of(80.56±0.45)kg were divided into three groups,they were control group,experimental groupⅠand experimental groupⅡ.Each group had 3 pens(replicates)and each pen had 10 pigs(barrow and sow in half).Pigs in the control group were fed a normal⁃protein diet containing 12% protein,those in the experimental groupⅠwere fed a low⁃protein diet containing 14%protein,and those in the experimental groupⅡwere fed the low⁃protein diet supplemented with probiotics(2.0×10^(9) CFU lactic acid bacteria and 2.0×108 CFU Saccharomyces cerevisiae per kg of the low⁃protein diet).The pre⁃test period lasted for 5 days,and the formal test period lasted for 42 days.The re⁃sults showed as follows:1)compared with the control group and experimental groupⅠ,the average daily gain was significantly increased(P<0.05),while the feed/gain ratio was significantly decreased in the experi⁃mental groupⅡ(P<0.05).2)Compared with the control group and experimental groupⅡ,the relative a⁃bundances of Oscillospirales,Lachnospirales,Lachnospiraceae,Ruminococcaceae,UCG⁃005,Faecalibacteri⁃um,Dialister and Fournierella were significantly decreased(P<0.05),while the relative abundance of Cellu⁃losilyticum was significantly increased in the experimental groupⅠ(P<0.05);compared with the control group,the relative abundances of Lachnospirales,Lactobacillales and Lachnospiraceae were significantly in⁃creased in experimental groupⅡ(P<0.05).3)There were 9,37 and 41 differential metabolites in fecal sam⁃ples between the experimental groupⅠvs.control group,the experimental groupⅡvs.control group,and the experimental groupⅠvs.experimental groupⅡ,respectively;the KEGG pathway enrichment analysis for different metabolites between groups obtained 27 enrichment pathways(P<0.05);compared with the control group and experimental groupⅠ,the expression level of 5⁃hydroxyindoleacetic acid was significantly increased(P<0.05),and the expression level of epinephrine was significantly decreased in fecal samples in the experi⁃mental groupⅡ(P<0.05);the expression level of N⁃acetyl⁃L⁃phenylalanine in fecal samples the in experi⁃mental groupⅠwas significantly lower than that in the control group and experimental groupⅡ(P<0.05);the expression levels of L⁃glutamine and D⁃glucuronic acid in fecal samples in the experimental groupⅡwere significantly higher than that in the experimental groupⅠ(P<0.05).4)Compared with the control group,the contents of ammonia nitrogen,skatole,total branch chain fatty acids and total short chain fatty acids in fe⁃cal samples were significantly reduced in the experimental groupⅠand experimental groupⅡ(P<0.05).Compared with the experimental groupⅠ,the content of acetic acid was significantly decreased(P<0.05),while the content of butyric acid was significantly increased in the experimental groupⅡ(P<0.05).The re⁃sults indicate that probiotics(lactic acid bacteria and Saccharomyces cerevicae)supplementation to a low⁃pro⁃tein diet can improve the structure of gut microbiota and metabolite expression in finishing pigs,reduce the contents of total branch chain fatty acids,ammonia nitrogen and skatole in feces,and increase the average daily gain and feed conversion efficiency of fattening pigs.