饲养方式对藏猪结肠消化酶活性、菌群结构及短链脂肪酸含量的影响

Effects of different feeding methods on digestive enzyme activity, microflora structure, and short chain fatty acids in colon of Tibetan pigs

摘要:

【目的】为探究饲养方式对藏猪结肠消化酶活性、菌群结构和短链脂肪酸含量的影响。【方法】研究分别选取5头相同月龄的放养藏猪和舍饲藏猪。屠宰采集结肠粪便样品，分别利用酶联免疫吸附法(enzyme linked immunosorbent assay, ELISA)试剂盒、高通量测序技术和气相色谱仪测定放养藏猪和舍饲藏猪结肠消化酶活性、菌群结构和短链脂肪酸含量。【结果】同一月龄下，放养藏猪的日增重显著低于舍饲藏猪(P<0.05)。放养藏猪结肠中纤维素酶和半纤维素酶的活性均显著高于舍饲藏猪(P<0.05)；2种饲养方式藏猪结肠的6种α多样性指数均无显著差异(P>0.05)，且主成分分析(principal component analysis, PCA)得到放养藏猪和舍饲藏猪结肠菌群存在一定的相似性。在门和科分类水平上，相较于舍饲藏猪，放养藏猪结肠中疣微菌门、黄杆菌科、月形单胞菌科、浮霉状菌科和伊格尔兹氏菌科的相对丰度显著升高，而链球菌科、韦荣氏球菌科、假单胞菌科、红环菌科、红螺菌科、乳杆菌科、理研菌科和巴斯德氏菌科的相对丰度显著降低(P<0.05)；在属和种分类水平上，共有7个菌属和4个菌种在两种饲养方式藏猪结肠中存在显著差异，依次为密螺旋菌属、瘤胃球菌属、伊格尔兹氏菌属、巨球型菌属、另枝菌属、假单胞菌属、链球菌属、普拉梭菌、埃氏巨球形菌、罗伊氏乳杆菌和普氏菌。短链脂肪酸研究表明，放养藏猪结肠中乙酸的含量显著高于舍饲藏猪(P<0.05)。【结论】在本试验条件下，饲养方式对藏猪结肠纤维素酶和半纤维素酶活性、菌群结构及乙酸含量均有影响。与舍饲藏猪相比，放养藏猪生长性能较差，但其对纤维素的降解能力更强。

Abstract:

[Objective] To explore the effects of feeding methods on the digestive enzyme activity, microflora structure, and short chain fatty acids in the colon of Tibetan pigs. [Methods] Five free-ranging Tibetan pigs and 5 captive Tibetan pigs with the same age were randomly selected. The pigs were slaughtered for the collection of colonic feces samples. The digestive enzyme activity, microflora structure, and content of short chain fatty acids in the samples were determined by enzyme linked immunosorbent assay (ELISA), high-throughput sequencing, and gas chromatography, respectively. [Results] The free-ranging Tibetan pigs had lower average daily gain and higher activities of cellulase and hemicellulase in the colon than the captive Tibetan pigs (P<0.05). The alpha diversity indexes of colon microflora had no significant difference (P>0.05) and the principal component analysis showed similarity in the microflora structure between the two groups of pigs. At the phylum and family levels, the colon of the free-ranging Tibetan pigs had higher relative abundance of Verrucomicrobia, Flavobacteriaceae, Selenomonadaceae, Planctomycetaceae, and Eggerthellaceae and lower relative abundance of Streptococcaceae, Veillonellaceae, Pseudomonadaceae, Rhodocyclaceae, Rhodospirillaceae, Lactobacillaceae, Rikenellaceae, and Pasteurellaceae than that of the captive Tibetan pigs (P<0.05). At the genus and species levels, 7 genera and 4 species showed significant differences in the relative abundance between the pigs fed with the two methods, including Treponema, Ruminococcus, Eggerthella, Megasphaera, Alistipes, Pseudomonas, Streptococcus, Prevotella copri, Lactobacillus reuteri, Megasphaera elsdenii, and Faecalibacterium prausnitzii. The content of acetic acid in the colon of free-ranging Tibetan pigs was higher in that in the colon of captive Tibetan pigs (P<0.05). [Conclusion] Feeding methods affect the activities of cellulase and hemicellulase, microflora structure, and acetic acid content in the colon of Tibetan pigs. The free-ranging grazing Tibetan pigs showed poorer growth performance and stronger cellulose-degrading ability than the captive Tibetan pigs.