本试验旨在研究补充不同剂量的牛至精油(OEO)是否可以通过调节瘤胃微生物区来促进小牛胃肠道的发育和增强其免疫能力。将24头70日龄健康无病荷斯坦公牛随机分为四组,对照组饲喂基础饮食,治疗组提供4克,6g,和8克牛至精油每天除了基础饮食。经过14天的预测试,进行了为期56天的正式测试。在标准测试期的第0天和第56天,给小牛称重,计算测试期间小牛的平均每日体重增加,并收集血清样本以测量免疫球蛋白的浓度(IgA,IgG,和血清中的IgM);在正式测试期的第56天,从小牛收集瘤胃液,并对16SrRNA进行测序以分析小牛瘤胃微生物群的变化。通过16SrRNA测序分析小牛瘤胃微生物群的变化。研究结果表明:(1)小牛补充OEO能显著提高日粮终重和平均日增重(p<0.05);(2)小牛补充OEO能显著提高血清免疫球蛋白IgA和IgM的浓度(p<0.05);(3)小牛补充OEO能显著提高瘤胃微生物的丰度和多样性(p<0.05);(4)小牛补充OEO能显著调节部分物种的相对丰度,通过LEfSe分析筛选出差异显著的生物标志物:g_Turicibacter,g_Romboutsia,f_肽链球菌科,f_梭菌科,g_梭状芽孢杆菌_sensu_stricto_1,o_梭状芽孢杆菌,g_未分类的_f_增效草科,c_科氏杆菌,o_Coriobacteriales,f_Atobobiaceae,g_Olsenella,p_放线菌,g_解氟科_UCG-011,f_解氟科,o_棒杆菌,g_棒状杆菌,f_棒杆菌科,g_Shuttleworthia,f_匈牙利纹科,o_norank_c_梭菌,g_糖酵素,g_链球菌,f_链球菌科,g_未分类的_o_蛇形螺旋,和f_未分类的_o_Oscillospirales(p<0.05,LDA≥3);(5)小牛补充OEO显着丰富了辅因子和维生素途径的代谢(p<0.05)。(6)采用超人相关分析,我们筛选了未分类的_c_梭菌,Shuttleworthia,和Christensenellaceae_R-7_组,三种对小牛有益的菌株。(7)每日补充8gOEO显著影响小牛瘤胃微生物群调节。
This experiment aimed to investigate whether supplementation of calves with different doses of oregano essential oil (OEO) could promote the development of the gastrointestinal tract and enhance the immune ability of calves by regulating the rumen microbiota. Twenty-four 70-day-old healthy and disease-free Holstein male calves were randomly divided into four groups, with the control group fed a basal diet, and the treatment group provided 4 g, 6 g, and 8 g of oregano essential oil per day in addition to the basal diet. After the 14-day pre-test, a 56-day formal test was conducted. At days 0 and 56 of the standard test period, calves were weighed, the average daily weight gain of calves during the test period was calculated, and serum samples were collected to measure the concentration of immunoglobulins (IgA, IgG, and IgM) in the serum; at day 56 of the formal test period, rumen fluid was collected from the calves, and 16SrRNA was sequenced to analyze changes in the rumen microbiota of the calves. The changes in the rumen microbiota of calves were analyzed by 16SrRNA sequencing. The results of the study showed that (1) OEO supplementation in calves significantly increased end weight and average daily gain (p < 0.05); (2) OEO supplementation in calves significantly increased serum concentrations of immunoglobulins IgA and IgM (p < 0.05); (3) OEO supplementation in calves significantly increased the abundance and diversity of rumen microbial organisms (p < 0.05); (4) OEO supplementation in calves significantly regulates the relative abundance of some species, and biomarkers with significant differences were screened by LEfSe analysis: g_Turicibacter, g_Romboutsia, f_Peptostreptococcaceae, f_Clostridiaceae, g_Clostridium_sensu_stricto_1, o_Clostridiales, g_unclassified_f_Synergistaceae, c_Coriobacteriia, o_Coriobacteriales, f_Atopobiaceae, g_Olsenella, p_Actinobacteriota, g_Defluviitaleaceae_UCG-011, f_Defluviitaleaceae, o_Corynebacteriales, g_Corynebacterium, f_Corynebacteriaceae, g_Shuttleworthia, f_Hungateiclostridiaceae, o_norank_c_Clostridia, g_Saccharofermentans, g_Streptococcus, f_Streptococcaceae, g_unclassified_o_Oscillospirales, and f_unclassified_o_Oscillospirales (p < 0.05, LDA ≥ 3); and (5) OEO supplementation in calves significantly enriched the metabolism of cofactors and vitamins pathway (p < 0.05). (6) Using Superman\'s correlation analysis, we screened unclassified_c_Clostridia, Shuttleworthia, and Christensenellaceae_R-7_group, three beneficial strains for calves. (7) Daily supplementation with 8g of OEO significantly affected rumen microbiota regulation in calves.