藏猪对饲粮纤维的消化及其与肠道微生物的相关性研究

旨在研究藏猪对饲粮纤维素和半纤维素的消化及其与粪便细菌的相关性，探索藏猪具备较强纤维降解能力的潜在因素。采用消化试验测定150 d放牧藏猪、舍饲藏猪和商品猪（杜×长×大猪，DLY猪）对饲粮纤维的表观消化率。采集粪便样品利用单分子实时测序技术，测定粪便细菌16S rRNA基因全长序列，分析粪便细菌群落的结构和多样性，采用Spearman相关分析获取饲粮纤维表观消化率与粪便中细菌群落的相关性。结果表明，放牧藏猪对饲粮纤维素和半纤维素的表观消化率显著高于舍饲藏猪与DLY猪（P<0.05）。在放牧藏猪、舍饲藏猪与DLY猪粪便细菌中共鉴定出15个门、26个纲、48个目、87个科、190个属、419个种。放牧藏猪粪便细菌中有1个门纤维杆菌门（Fibrobacteres）、3个属拟普雷沃菌属（Alloprevotella）、纤维杆菌属（Fibrobacter）与琥珀酸弧菌属（Succinivibrio）、3个种（Alloprevotella rava、Fibrobacter intestinalis、Succinivibrio dextrinosolvens）相对丰度显著高于舍饲藏猪与DLY猪（P<0.05），并与饲粮纤维表观消化率呈显著正相关（P<0.05）。综上所述，放牧藏猪具备较强的纤维消化能力，这种能力与粪便中的纤维降解菌密切相关。

Study on Dietary Fibre Digestion and Its Correlation with Intestinal Microbiome of Tibetan Pigs

With the aim of exploring the potential factors of strong fibre degradation ability for Tibetan pigs, this experiment was conducted to study the digestion of dietary cellulose and hemicellulose and their correlation with the faecal bacteria of Tibetan pigs. The apparent digestibility of dietary fibre to grazing Tibetan pigs, captive Tibetan pigs and commercial pigs[Duroc×Landrace×Yorkshire (DLY) pigs] at 150 days of age was determined by digestion test. Faecal samples were collected, and the full-length sequence of the 16S rRNA gene of faecal bacteria was determined by single molecule real-time sequencing technology. The structure and diversity of faecal bacterial community were analysed. Spearman correlation analysis was used to determine the correlation between apparent digestibility of dietary fibre and faecal bacterial community. Results showed that the apparent digestibility of dietary cellulose and hemicellulose of grazing Tibetan pigs was significantly higher than that of captive Tibetan pigs and DLY pigs (P<0.05). A total of 15 phyla, 26 classes, 48 orders, 87 families, 190 genera and 419 species of bacteria were identified from faeces of grazing Tibetan pigs, captive Tibetan pigs and DLY pigs. Furthermore, there were 1 phylum (Fibrobacteres), 3 genera (Alloprevotella, Fibrobacter, and Succinivibrio) and 3 species (Alloprevotella rava, Fibrobacter intestinalis, and Succinivibrio dextrinosolvens) which relative abundance in grazing Tibetan pigs were significantly higher than those of captive Tibetan pigs and DLY pigs (P<0.05), which were significantly positively correlated with apparent digestibility of dietary fibre (P<0.05). In conclusion, grazing Tibetan pigs have strong ability of fibre digestion, which was closely related to the fibre-degrading bacteria in faeces.