Jo Jang-Hoon, Ghassemi Nejad Jalil, Peng Dong-Qiao, Kim Hye-Ran, Kim Sang-Ho, Lee Hong-Gu
Department of Animal Science and Technology, Sanghuh College of Life Sciences, Konkuk University, Seoul 05029, Korea.
Animal Nutrition and Physiology Team, National Institute of Animal Science, RDA, Wanju 55365, Korea.
Animals (Basel). 2021 Mar 6;11(3):722. doi: 10.3390/ani11030722.
This study aims to characterize the influence of short-term heat stress (HS; 4 day) in early lactating Holstein dairy cows, in terms of triggering blood metabolomics and parameters, milk yield and composition, and milk microRNA expression. Eight cows (milk yield = 30 ± 1.5 kg/day, parity = 1.09 ± 0.05) were homogeneously housed in environmentally controlled chambers, assigned into two groups with respect to the temperature humidity index (THI) at two distinct levels: approximately ~71 (low-temperature, low-humidity; LTLH) and ~86 (high-temperature, high-humidity; HTHH). Average feed intake (FI) dropped about 10 kg in the HTHH group, compared with the LTLH group ( = 0.001), whereas water intake was only numerically higher ( = 0.183) in the HTHH group than in the LTLH group. Physiological parameters, including rectal temperature ( = 0.001) and heart rate ( = 0.038), were significantly higher in the HTHH group than in the LTLH group. Plasma cortisol and haptoglobin were higher ( < 0.05) in the HTHH group, compared to the LTLH group. Milk yield, milk fat yield, 3.5% fat-corrected milk (FCM), and energy-corrected milk (ECM) were lower ( < 0.05) in the HTHH group than in the LTLH group. Higher relative expression of milk miRNA-216 was observed in the HTHH group ( < 0.05). Valine, isoleucine, methionine, phenylalanine, tyrosine, tryptophan, lactic acid, 3-phenylpropionic acid, 1,5-anhydro-D-sorbitol, myo-inositol, and urea were decreased ( < 0.05). These results suggest that early lactating cows are more vulnerable to short-term (4 day) high THI levels-that is, HTHH conditions-compared with LTLH, considering the enormous negative effects observed in measured blood metabolomics and parameters, milk yield and compositions, and milk miRNA-216 expression.
本研究旨在描述短期热应激（HS；4天）对初产荷斯坦奶牛的影响，涉及触发血液代谢组学和参数、产奶量和成分以及乳汁微小RNA表达。八头奶牛（产奶量 = 30 ± 1.5千克/天，胎次 = 1.09 ± 0.05）被均匀安置在环境可控的牛舍中，根据温度湿度指数（THI）分为两组，处于两个不同水平：约71（低温、低湿度；LTLH）和约86（高温、高湿度；HTHH）。与LTLH组相比，HTHH组的平均采食量（FI）下降了约10千克（P = 0.001），而HTHH组的饮水量仅在数值上高于LTLH组（P = 0.183）。HTHH组的生理参数，包括直肠温度（P = 0.001）和心率（P = 0.038），显著高于LTLH组。与LTLH组相比，HTHH组的血浆皮质醇和触珠蛋白更高（P < 0.05）。HTHH组的产奶量、乳脂产量、3.5%乳脂校正乳（FCM）和能量校正乳（ECM）低于LTLH组（P < 0.05）。在HTHH组中观察到乳汁miRNA - 216的相对表达较高（P < 0.05）。缬氨酸、异亮氨酸、蛋氨酸、苯丙氨酸、酪氨酸、色氨酸、乳酸、3 - 苯丙酸、1,5 - 脱水 - D - 山梨醇、肌醇和尿素减少（P < 0.05）。这些结果表明，与LTLH相比，初产奶牛在短期（4天）高THI水平（即HTHH条件）下更易受影响，考虑到在测量的血液代谢组学和参数、产奶量和成分以及乳汁miRNA - 216表达中观察到的巨大负面影响。
