Effects of fermented Chinese herbal medicines on milk performance and immune function in late-lactation cows under heat stress conditions
Effects of fermented Chinese herbal medicines on milk performance and immune function in late-lactation cows under heat stress conditions
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DOI：
10.1093/jas/sky270
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发表时间：
2018-10-01
影响因子：
3.3
通讯作者：
Zhao, JuanJuan
中科院分区：
文献类型：
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作者：
Shan, Chun-Hua;Guo, Jianjun;Zhao, JuanJuan
热应激（HS）造成重大经济损失，已成为全球乳制品行业的持续挑战。本研究的目的是评估HS条件下日粮补充剂对泌乳后期奶牛产奶性能和免疫功能的影响。该补充剂是由18种草药组成的发酵中草药混合物。将40头泌乳荷斯坦奶牛（初始BW为560 +/- 51.0 kg，DIM为230 +/- 10.0，每天产奶量为16 +/- 3.0 kg）随机分配至4个处理组（每组10头奶牛）。每组饲喂添加0、25、50或100 g CHMs/头奶牛/天的日粮。奶牛被安置在高环境温度-湿度指数（平均74.5）的实验期为42天，在夏季。分别在第14、28和42天评价产奶量、成分、免疫应答（包括血液淋巴细胞凋亡率）、血清生化指标和淋巴细胞中的基因表达。结果表明，在整个试验期间，添加50或100 g/d中草药的产奶量、乳脂和蛋白质含量均高于不添加中草药的组（P < 0.05）。随着中药剂量的增加，淋巴细胞和白细胞计数增加（P < 0.01）。流式细胞仪检测结果显示，中药组淋巴细胞早期和晚期凋亡率均明显降低（P < 0.05）。研究了免疫相关的生物化学和基因转录应答，包括细胞因子（IL-1、IL-2、IL-6和IL-12）、凋亡（巴克、Mcl-1、Bax、Bcl-2、Bcl-xl和P53）和免疫球蛋白（伊加、IgG和IgM）。100 g/d组血清IL-2、IL-6水平及IL-2 mRNA表达均高于对照组（P < 0.05）。但随着中药剂量的增加，血清IL-1水平呈下降趋势（P = 0.08），100 g/d剂量组IL-1 mRNA表达下调幅度达24%（P = 0.02）。100 g/d组血清Bax水平降低（P < 0.01），Bcl-2水平升高（P = 0.01）。50和100 g/d组Bax和巴克基因表达下调（P < 0.05），Bcl-2和Bcl-xl基因表达上调（P < 0.05）。中草药对P53和Mcl-1 mRNA表达无影响（P > 0.10）。此外，50和100 g/d组血清IgG水平显著高于未补组（P < 0.01）。总之，CHMs补充剂可以改善奶牛在HS条件下的产奶性能和免疫功能。
Heat stress (HS) causes significant economic losses and has become a continual challenge in the dairy industry worldwide. The objective of this study was to evaluate the effects of a dietary supplement on milk performance and immune function in late-lactation cows under HS conditions. The supplement was a fermented Chinese herbal medicines (CHMs) mixture consisting of 18 herbs. Forty lactating Holstein cows (560 +/- 51.0 kg of initial BW, 230 +/- 10.0 DIM, 16 +/- 3.0 kg of milk per day) were randomly assigned into 4 treatment groups (10 cows per group). Each group was fed a dietary supplemented with 0, 25, 50, or 100 g CHMs per cow per day. Cows were housed at high ambient temperature-humidity index (average 74.5) for an experimental period of 42 d during the summer months. Milk yield, composition, immune responses involving blood lymphocyte apoptosis rate, serum biochemical parameters, and genes expression in lymphocytes were evaluated on days 14, 28, and 42, respectively. Results showed that milk yield, milk fat, and protein content were greater (all P < 0.05) for 50 or 100 g/d CHMs compared with the group without CHMs supplements throughout the experimental period. On the other hand, increasing CHMs dose demonstrated a greater lymphocyte or leukocyte count (P < 0.01). By flow cytometry analysis, early or late apoptosis rate of the lymphocytes was decreased (P < 0.05) by CHMs supplements. The immunity-related biochemistry and genes transcript responses involving cytokines (IL-1, IL-2, IL-6, and IL-12), apoptosis (Bak, Mcl-1, Bax, Bcl-2, Bcl-xl, and P53), and immunoglobulins (IgA, IgG, and IgM) were investigated. Compared with the unsupplemented group, the serum IL-2 and IL-6 levels, as well as IL-2 mRNA expression, increased (P < 0.05) for 100 g/d. However, the serum IL-1 level tended to decrease (P = 0.08) with increasing CHMs dose, and IL-1 mRNA expression was down-regulated (P = 0.02) by up to 24% for 100 g/d. Additionally, the serum Bax level decreased (P < 0.01) and Bcl-2 level increased (P = 0.01) for 100 g/d. Bax and Bak mRNA expressions were down-regulated (P < 0.05), and Bcl-2 and Bcl-xl expression were up-regulated (P < 0.05) for 50 or 100 g/d. The mRNA expressions of P53 and Mcl-1 were not affected by CHMs (P > 0.10). Besides, serum IgG levels were greater (P < 0.01) for 50 or 100 g/d, compared with unsupplemented group. In conclusion, CHMs supplements may improve milk performance and immune function in dairy cows under HS conditions.