不同生长阶段舜皇山土猪肠道微生物组成与多样性

目的 挖掘肠道微生物在舜皇山土猪耐粗饲及抗病等方面的作用,为舜皇山土猪的饲养与保护以及益生菌的开发提供理论依据。 方法 采集3个生长阶段的舜皇山土猪粪便样品,各4~5组,进行16S rDNA V3-V4区基因高通量测序,分析其微生物的组成及多样性。 结果 舜皇山土猪肠道微生物主要由拟杆菌门(Bacteroides)、厚壁菌门(Firmicutes )组成,但这两个主要门类的丰富度在各生长阶段有较大差异,且哺乳猪肠道的变形菌门(Proteobacteria)丰富度明显高于其他生长阶段。舜皇山土猪肠道内的Firmicutes/Bacteroides(F/B)比例较低,具有较高的瘦肉率的潜力,但并未表现出很高的瘦肉率,推测与其自身生长缓慢有关。不同生长阶段舜皇山土猪肠道微生物中的优势菌属有所不同,但普氏菌、考拉杆菌属、瘤胃菌科是它们的共性菌,这与商品化猪肠道的优势属(主要是乳杆菌、链球菌等)存在明显差异。考拉杆菌属在肠道微生态的动态平衡方面起着至关重要的作用,并且在含致病菌较少的保育猪中丰富度较高,推测其在舜皇山土猪抗病特性方面具有重要作用。与其他两个生长阶段的猪相比,哺乳猪丰富度差异显著的细菌菌属有23种,保育猪12种,育肥猪27种,但它们含有较多的益生菌,如SCFAs产生菌、木聚糖降解菌、纤维降解菌等,推测与其耐粗饲料特性相关。 结论 舜皇山土猪的发育状态以及饮食习惯影响其肠道微生物的组成。舜皇山土猪的瘦肉率受肠道内F/B比例的影响,同时其自身生长速率也有可能影响其瘦肉率。考拉菌属可能在舜皇山土猪抗病特性方面具有重要作用。舜皇山土猪肠道内的木聚糖降解菌、纤维降解菌等微生物是其耐粗饲的主要原因。

Composition and diversity of gut microbiota in different growth stages of Shunhuang Shan native pigs

Objective To explore the role of gut microbiota in crude feeding tolerance and disease resistance of Shunhuang Shan native pigs, and provide theoretical basis for the breeding and protection of the pigs in different growth stages, and for the development of probiotics. Methods The fecal samples of Shunhuang Shan native pigs at 3 growth stages were collected, 4 to 5 samples in each group. 16 S rDNA gene high-throughput sequencing in V3-V4 region was performed to analyze the microbial composition and diversity. Results Bacteroides and Firmicutes were the dominant microflora, but the abundance of these two main phyla varied greatly in each growth stage, and the abundance of Proteobacteria in the intestine of lactating pigs was significantly higher than that in other growth stages. The ratio of Firmicutes to Bacteroides in the intestine of Shunhuang Shan native pigs was lower, suggesting a potential of high lean meat rate which however was not observed and was speculated as being related to their slow growth. The dominant genera of gut microbiota in different growth stages were quite different, but usually were Prevotella, Phascolarctobacterium and Ruminococcaceae, which was obviously different from those(Lactobacillus and Streptococcus) of commercial pigs. Phascolarctobacterium played an important role in the dynamic balance of intestinal microecology and its abundance was higher in the nursery pigs with less pathogenic bacteria. Therefore, we speculated that Phascolarctobacterium played an important role in the disease resistance of Shunhuang Shan native pigs. There were significant differences in the abundance among 23 bacteria in lactating pigs, 12 bacteria in nursery pigs and 27 bacteria in fattening pigs, respectively. Shunhuang Shan native pigs had a large number of probiotics, such as SCFAs producing bacteria, Xylan-degrading bacteria, and fiber degrading bacteria, etc., which might be related to their resistance to roughage. Conclusion The development status and dietary habits of Shunhuang Shan native pigs affect the composition of gut microbiota, the lean meat rate of them affects the ratio of F/B in intestinal tract, and their growth rates may also affect the lean meat rate. Phascolarctobacterium may play an important role in their resistance to diseases, and various degrading gut microbiota are the reason for their tolerance to coarse feeding.