Sun Fuyu, Zhao Qingyao, Chen Xiaoyang, Zhao Guangyong, Gu Xianhong
State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
College of Animal Science and Technology, China Agricultural University, Beijing, China.
Front Vet Sci. 2022 Feb 25;9:840726. doi: 10.3389/fvets.2022.840726. eCollection 2022.
Non-nutritive oral behaviors, especially tongue rolling, are prevalent in the stabled cow population. These behaviors mean that the environment or management process might not suit the cows, suggesting low welfare. However, few researches have reported the physiological indicators or production performance of dairy cows with the stereotyped behavior. This study aimed to determine physical conditions, daily activity, rumen fermentation, and milk production of cows with tongue-rolling behavior. Three hundred and fifty nine Holstein cows in the same barn and lactation stage were subjected to scan sampling behavior observations 126 times for 7 days. Ten cows with high-frequency tongue-rolling behavior (TON) and 10 cows without abnormal oral behavior (CON) were selected for further study. Serum sample, ruminal fluid, milk sample, and behavior record video of TON and CON cows were collected. TON cows had more drinking behavior and more stable lying behavior than the CON cows during the daytime. The body condition score of the TON cows decreased, while the milk yield, yield of milk fat, protein, and lactose in the study period increased. The TON cows had lower ruminal fluid pH, acetate/propionate ratio, and total volatile acid. The bacterial diversity in the ruminal fluid was not different between the two groups. Compared to CON cows, the TON cows had a higher level of serum stress indicators, such as cortisol, thyroid hormone, and norepinephrine, which positively correlated to the frequency of tongue-rolling behavior. Meanwhile, the TON cows had a higher level of lactate dehydrogenase, serum glucose, total triglyceride, total cholesterol, and Interleukin 6. Overall, it means they suffer from higher levels of stress and have higher energy metabolism for a long time when cows show tongue-rolling behavior. TON cows had suffered a higher stress level and had higher energy metabolic status for a long time. The TON cows might have better heat tolerance to the thermal environment by more lying and drinking time. Our data revealed the changes in milk production, physiological stress indicators of dairy cows with high-frequency tongue rolling behavior, which will provide essential knowledge for the in-depth understanding of tongue rolling behavior in dairy cows.
非营养性口腔行为，尤其是卷舌行为，在舍饲奶牛群体中很普遍。这些行为意味着环境或管理过程可能不适合奶牛，表明福利水平较低。然而，很少有研究报道有刻板行为的奶牛的生理指标或生产性能。本研究旨在确定有卷舌行为的奶牛的身体状况、日常活动、瘤胃发酵和产奶量。对同一牛舍且处于相同泌乳阶段的359头荷斯坦奶牛进行了为期7天、共126次的扫描抽样行为观察。选择10头高频卷舌行为奶牛（TON）和10头无异常口腔行为奶牛（CON）进行进一步研究。收集了TON和CON奶牛的血清样本、瘤胃液样本、牛奶样本以及行为记录视频。白天，TON奶牛比CON奶牛有更多的饮水行为和更稳定的躺卧行为。TON奶牛的体况评分下降，而研究期间的产奶量、乳脂产量、蛋白质产量和乳糖产量增加。TON奶牛的瘤胃液pH值、乙酸/丙酸比值和总挥发性酸较低。两组瘤胃液中的细菌多样性没有差异。与CON奶牛相比，TON奶牛的血清应激指标水平较高，如皮质醇、甲状腺激素和去甲肾上腺素，这些指标与卷舌行为的频率呈正相关。同时，TON奶牛的乳酸脱氢酶、血清葡萄糖、总甘油三酯、总胆固醇和白细胞介素6水平较高。总体而言，这意味着当奶牛表现出卷舌行为时，它们长期承受着更高水平的应激，并且能量代谢更高。TON奶牛长期承受着更高的应激水平，且能量代谢状态更高。TON奶牛可能通过更多的躺卧和饮水时间对热环境具有更好的耐热性。我们的数据揭示了高频卷舌行为奶牛的产奶量和生理应激指标的变化，这将为深入了解奶牛卷舌行为提供重要知识。
