College of Animal Science, Xinjiang Agricultural University, Xinjiang Key Laboratory of Herbivore Nutrition for Meat & Milk Production, Urumqi, Xinjiang, 830052, China.
BMC Vet Res. 2022 Nov 17;18(1):407. doi: 10.1186/s12917-022-03510-2.
Compared with the stomach of ruminant cattle, the stomach of horse is small and mainly for chemical digestion, but the microorganisms in the stomach play an important role in maintaining the homeostasis of the internal environment. Due to the complexity of the microbes in the stomach, little is known about the diversity and structure of bacteria in the equine stomach. Grains are the main energy source for plant-eating livestock and energy is derived through enzymatic hydrolysis of grains into glucose or their microbial fermentation into Volatile fatty acids (VFA). However, the mechanism through which these ingested grains are chemically digested as well as the effect of these grains on the stomach remains elusive. This study explored the effects of feeding different grains (corn, oats, and barley) on bacterial diversity, structure, and composition in the foal's stomach content. Furthermore, the effects of different grains on the vitality of starch digestion-related stomach enzymes were investigated.
No significant differences were observed (P > 0.05) in the bacterial rarefaction curves of Operational Taxonomic Units (OTUs) and diversity of the stomach microbiota in all foals. This study also revealed the statistical differences for Firmicutes, Cyanobacteria, Actinobacteria, Fibrobacteres, Lactobacillaceae, Streptococcaceae, Unidentified_Clostridiales, Prevotellaceae, Lactobacillus, Streptococcus, Unidentified_Cyanobacteria, Unidentified_Clostridiales, Lactococcus, Sphingomonas, Lactobacillus_hayakitensis, Lactobacillus_equigenerosi, and Clostridium_perfringens. The linear discriminant analysis effect size analysis revealed 9 bacteria at each classification level. The functional analysis of species information by using FAPROTAX software was able to predict 35 functions, and the top 5 functions were chemoheterotrophy, fermentation, animal_parasites_or_symbionts, nitrate_reduction, and aerobic_chemoheterotrophy. The study also revealed statistical differences for pH, glucose concentration, β-amylase, maltase, and amylase.
The different grains had no significant effect on the microbial diversity of the stomach content of the foal. However, the relative bacterial abundances differed significantly in response to different diets. Particularly, oats fed to the foals significantly increased the relative abundance of Firmicutes, Lactobacillaceae, Lactobacillus, and Lactobacillus_hayakitensis. The grain had no significant effect on the pH of the stomach content, glucose concentration, and enzyme viability in the foal.
与反刍动物的牛胃相比，马胃较小，主要进行化学消化，但胃中的微生物在维持内环境平衡方面起着重要作用。由于胃中的微生物复杂性，人们对马胃中细菌的多样性和结构知之甚少。谷物是食草动物的主要能量来源，能量通过谷物的酶解转化为葡萄糖或微生物发酵为挥发性脂肪酸（VFA）来获得。然而，这些摄入的谷物是如何进行化学消化的，以及这些谷物对胃的影响，仍不得而知。本研究探讨了不同谷物（玉米、燕麦和大麦）对马驹胃内容物中细菌多样性、结构和组成的影响。此外，还研究了不同谷物对淀粉消化相关胃酶活力的影响。
所有马驹的胃微生物群落操作分类单元（OTUs）和多样性的细菌稀有曲线均无显著差异（P>0.05）。本研究还揭示了厚壁菌门、蓝细菌门、放线菌门、纤维杆菌门、乳杆菌科、链球菌科、未鉴定的梭菌目、普雷沃氏菌科、乳杆菌属、链球菌属、未鉴定的蓝细菌门、未鉴定的梭菌目、乳球菌属、鞘氨醇单胞菌属、拉氏乳杆菌、发酵乳杆菌和产气荚膜梭菌的统计学差异。线性判别分析效应量分析显示每个分类水平有 9 种细菌。使用 FAPROTAX 软件对物种信息进行功能分析，能够预测 35 种功能，前 5 种功能是化能异养、发酵、动物寄生虫或共生体、硝酸盐还原和需氧化能异养。研究还揭示了 pH 值、葡萄糖浓度、β-淀粉酶、麦芽糖酶和淀粉酶的统计学差异。
不同谷物对马驹胃内容物的微生物多样性没有显著影响。然而，不同饮食对相对细菌丰度的影响有显著差异。特别是燕麦喂养的马驹显著增加了厚壁菌门、乳杆菌科、乳杆菌属和拉氏乳杆菌的相对丰度。谷物对马驹胃内容物的 pH 值、葡萄糖浓度和酶活力没有显著影响。
