Differences of intestinal microorganism in pigs under different feeding modes

Different feeding methods, such as extensive feeding pattern (EP) and complete intensive feeding pattern (CP), have an influence on growth, fat accumulation and disease resistance of pigs. Intestinal microorganisms may be an important factor leading to this phenomenon. Therefore, in order to investigate and compare the gut microbiota structure in CP and EP groups, a total of 20 Chuying black pigs were divided into two groups as CP (n = 10) and EP (n = 10) and fed the same diet. The fecal microbial composition was profiled using 16S ribosomal RNA (rRNA) gene sequencing. Our results showed that seventeen predominant genera,which account for more than 95% of all gut microbes at the class level, present in each pig sample and constituted a phylogenetic core microbiota. Most of core microbial flora, such as Actinobacteria, Bacilli, Deltaproteobacteria, Fibrobacteria, Epsilonproteobacteria, Oligosphaeria, Sphingobacteriia, Spirochaetia, in CP group were significantly higher than that of EP group (P < 0.05), while the Gammaproteobacteria was significantly lower than the EP group (P < 0.05). The CP group had significantly higher community diversity, richness and evenness than the EP group (P < 0.05) in present study. Functional prediction indicated that intestinal microbial species may lead to higher growth and fat accumulation capacity in CP group than in EP group, but the disease resistance was weaker than EP group. In conclusion, this study suggested that extensive feeding pattern pigs have a wide range of sports venues and better animal welfare, which has a certain impact on reducing the occurrence of diseases and neurological symptoms. Therefore, it is suggested that in the process of raising hogs in captivity, a certain degree of free range or appropriate expansion of the exercise space for hogs should be carried out to improve animal welfare, which is conducive to reducing the occurrence of diseases and neurological symptoms.

不同饲养模式，如粗放饲养模式（extensive feeding pattern, EP）与全集约化饲养模式（complete intensive feeding pattern, CP），均可对猪的生长性能、脂肪沉积及抗病能力产生影响。肠道微生物或为介导该效应的关键因素。为此，本研究为探究并比较CP组与EP组猪的肠道菌群结构，将20头楚英黑猪（Chuying black pigs）分为CP组（n=10）与EP组（n=10），两组饲喂相同日粮。采用16S核糖体RNA（16S ribosomal RNA, rRNA）基因测序技术对粪便微生物组成进行解析。研究结果显示，所有猪粪样中均存在17个优势菌属，其在纲水平上占肠道总菌群的95%以上，共同构成系统发育核心菌群。CP组多数核心微生物类群，如放线菌纲（Actinobacteria）、芽孢杆菌纲（Bacilli）、δ-变形菌纲（Deltaproteobacteria）、纤维杆菌纲（Fibrobacteria）、ε-变形菌纲（Epsilonproteobacteria）、寡球菌纲（Oligosphaeria）、鞘氨醇杆菌纲（Sphingobacteriia）、螺旋体纲（Spirochaetia），其相对丰度均显著高于EP组（P < 0.05）；而γ-变形菌纲（Gammaproteobacteria）的相对丰度则显著低于EP组（P < 0.05）。本研究中，CP组的菌群群落多样性、丰富度与均匀度均显著优于EP组（P < 0.05）。功能预测结果表明，肠道微生物菌群或可使CP组猪具备更高的生长与脂肪沉积能力，但抗病能力弱于EP组。综上，本研究发现粗放饲养模式的猪拥有更广阔的运动场地与更优的动物福利，这对降低疾病与神经症状的发生具有一定积极作用。因此，在集约化生猪养殖过程中，建议适度开展散养或适当扩大生猪的运动空间，以改善动物福利，进而降低疾病与神经症状的发生概率。