Probiotic Supplementation Regulated Swine Growth Performance, Fecal Odor Reduction and Carcass Characteristics by Modulating Intestinal Microbiome and Butanoate Metabolism

Using probiotics as a substitute for antibiotic growth promoters and reducing odor has received increasing attention in animal science. Despite the extensive investigation into the effects of probiotic administration on swine growth performance and odor reduction by short study durations, the analysis of carcass characteristics and potential mechanistic insights involving gut microbiota and downstream pathways is still few. In this study, the 48 LYD crossbred piglets treated with three probiotic strains, Lactobacillus kefiranofaciens M1, Bacillus subtilis S14, and B. amyloliquefaciens S20 were divided into four groups: a control (CON) group, M1 group, SA group, and SAM group. A pig-feeding experiment was conducted from the weaning period to the finishing phase, during which growth performance, fecal odor, intestinal microbiota, and carcass characteristics were analyzed. The results demonstrated that administration of the probiotics led to increased body weight and average daily weight gain, particularly notable during the weaning and finishing periods. Additionally, the SA and SAM groups significantly reduced skatole concentration in feces, thereby mitigating fecal odor. Furthermore, probiotic supplementation was associated with increased carcass weight, with the SAM group exhibiting significantly higher tenderloin weight than the CON group. Microbiota analysis revealed taxa exhibiting significant differences in abundance among groups, with corresponding LEfSe findings identifying them as crucial gastrointestinal bacterial biomarkers. Spearman correlation coefficient analysis further indicated higher levels of skatole, urease, and butanoate metabolism function in probiotic-treated groups compared to CON groups. Administering Bacillus subtilis S14 and B. amyloliquefaciens S20 (SA group) impacted growth performance, reduced fecal odor, and enhanced pig carcass quality. The identified probiotic strains hold promise as feed additives, offering a potential solution to challenges encountered by the swine industry.

在动物科学领域，将益生菌（probiotics）替代抗生素生长促进剂并降低气味排放的研究日益受到关注。尽管已有大量短期研究探讨了益生菌施用对猪生长性能和气味减排的影响，但关于胴体特性分析以及涉及肠道菌群和下游通路的潜在机制解析的研究仍较为匮乏。本研究将48头LYD杂交断奶仔猪分为四组，分别饲喂三种益生菌菌株——开菲尔乳杆菌M1（Lactobacillus kefiranofaciens M1）、枯草芽孢杆菌S14（Bacillus subtilis S14）和解淀粉芽孢杆菌S20（B. amyloliquefaciens S20），具体分组为对照组（CON组）、M1组、SA组及SAM组。本实验从仔猪断奶期持续至育肥期，期间对猪的生长性能、粪便气味、肠道菌群及胴体特性进行了分析测定。结果显示，饲喂益生菌可提升仔猪的体重及平均日增重，该效果在断奶期与育肥期尤为显著。此外，SA组与SAM组可显著降低粪便中粪臭素（skatole）的浓度，从而缓解粪便异味。此外，饲喂益生菌可提升胴体重，其中SAM组的里脊重量显著高于CON组。菌群分析显示，各组间存在丰度显著差异的微生物类群，结合线性判别分析效应大小（LEfSe）分析结果，这些类群被鉴定为关键的胃肠道细菌生物标志物。斯皮尔曼相关系数分析进一步显示，与CON组相比，益生菌处理组的粪臭素、脲酶及丁酸代谢通路功能的丰度水平更高。饲喂枯草芽孢杆菌S14与解淀粉芽孢杆菌S20组成的SA组，可改善猪的生长性能、降低粪便异味并提升胴体品质。本研究筛选出的益生菌菌株有望作为饲料添加剂，为生猪养殖业面临的相关难题提供潜在解决方案。