热应激(HS)在世界范围内的养羊业造成严重的经济损失。本研究的目的是研究草药配方(HF)补充剂对生长的影响,消化率,抗氧化能力,HS下育肥羔羊瘤胃微生物。根据中药“Jun-Chen-Zuo-Shi”的配伍理论,制备了由四种草药组成的HF。将二百四十只3个月的断奶羔羊(初始体重36.61±0.73kg)随机分为四组,补充0%(对照),0.5%,1.0%,和饮食中1.5%的HF。在整个35天的实验期间,所有羔羊都暴露于平均温湿度指数为79.7的HS条件下。增长业绩,表观消化率,和抗氧化活性,涉及抗氧化酶和热休克蛋白(HSPs),在试验结束时测量,以及细菌和古细菌中的微生物群落。结果表明,0.5%HF使平均日增重(P=0.02)增加13.80%,饲料增重比(P=0.03)降低14.68%,与控制相比。随着HF剂量的增加,乙醚提取物和酸性洗涤纤维的消化率表现出立方关系(P<0.01)和二次关系(P=0.03),分别;此外,谷胱甘肽过氧化物酶和过氧化氢酶活性呈二次增加(P<0.01)。0.5%HF患者的血清HSP60,HSP70和HSP90水平均低于对照组(P<0.05)。另一方面,总挥发性脂肪酸,乙酸,丁酸,戊酸,异戊酸水平随HF剂量呈二次增加(P≤0.01)。从瘤胃微生物中,HF补充剂提高了细菌群落的丰度和多样性。特别是0.5%HF组,操作分类单位是所有组中最大的。与控制相比,HF补充剂的Prevotella丰度从0.5%增加到1.5%,增加了35.57%到60.15%,和蔗糖的丰度随剂量呈二次模式(P=0.02)。此外,当羔羊饲喂0.5至1.5%的HF时,古细菌群落中的甲烷数量增加了0.2至3.3倍。总之,膳食HF补充剂将有助于减轻羔羊的HS,我们的结果表明饮食中补充0.5%HF的最佳剂量。
Heat stress (HS) causes severe economic losses in sheep industry worldwide. The objective of the present study was to investigate the effects of a herbal formula (HF) supplement on growth, digestibility, antioxidant capacity, and rumen microbes in fattening lambs under HS. The HF composed of four herbs was prepared based on the theory of compatibility of Chinese medicine \"Jun-Chen-Zuo-Shi\". Two-hundred forty 3-month weaned lambs (initial weight 36.61 ± 0.73 kg) were randomly allocated into four groups, supplemented 0% (Control), 0.5%, 1.0%, and 1.5% HF in diets. All lambs were exposed to HS conditions with 79.7 of average temperature-humidity index throughout an experimental period of 35 days. Growth performance, apparent digestibility, and antioxidant activities, involving antioxidant enzymes and heat shock proteins (HSPs), were measured at the end of trial, as well as microbial communities in bacteria and archaea. Results showed that 0.5% HF increased (P = 0.02) average daily gain by 13.80% and decreased feed-to-gain ratio (P = 0.03) by 14.68%, compared to control. With increasing HF doses, the digestibility of ether extract and acid detergent fiber demonstrated a cubical (P < 0.01) and quadratic (P = 0.03) relation, respectively; moreover, glutathione peroxidase and catalase activities demonstrated a quadratic increase (P < 0.01). Serum levels of HSP60, HSP70, and HSP90 for 0.5% HF were lower than that in control (P < 0.05). On the other hand, total volatile fatty acid, acetic acid, butyric acid, valeric acid, and isovaleric acid levels exhibited quadratic increases (P ≤ 0.01) with HF doses. From rumen microbes, the abundance and diversity of bacterial community were improved by HF supplements. Particularly for 0.5% HF group, the operational taxonomic units were the greatest among all groups. Compared to control, Prevotella abundance for HF supplements from 0.5 to 1.5% increased by 35.57 to 60.15%, and Succiniclasticum abundance demonstrated a quadratic pattern (P = 0.02) with doses. Additionally, Methanosphaera abundance in archaeal community raised by 0.2 to 3.3-folds when lambs were fed the HF additions of 0.5 to 1.5%. In summary, dietary HF supplements would contribute to alleviating HS in lambs, and our results suggest the optimal dose of 0.5% HF supplement in diet.