Ghassemi Nejad J, Lee B-H, Kim J-Y, Chemere B, Sung K-I, Lee H-G
Department of Animal Science and Technology, Sanghuh College of Life Sciences, Konkuk University, Seoul 05029, Republic of Korea; Team of An Educational Program for Specialists in Global Animal Science, Brain Korea 21 Plus Project, Sanghuh College of Life Sciences, Konkuk University, Seoul 05029, Republic of Korea.
National Institute of Animal Science, RDA, Cheonan 31000, Republic of Korea.
Domest Anim Endocrinol. 2021 Apr;75:106581. doi: 10.1016/j.domaniend.2020.106581. Epub 2020 Oct 23.
Through the analysis of blood and hair samples, this study evaluated the effects of grazing in alpine areas on welfare indices and indicators of stress in dairy cows. Twenty-one Holstein dairy cows (body weight: 637 ± 21.5 kg; days in milk: 133 ± 17.7, and second parity) were randomly assigned to 3 groups: control (nongrazing), 12 h of alpine grazing (12 hG), and 24 h of alpine grazing (24 hG). Blood samples for plasma collection were taken for 3 consecutive days at the end of the experiment. Hair samples were collected at the beginning and end of the experiment. Hormone measurements included cortisol, serotonin, and dehydroepiandrosterone (DHEA) in both plasma and hair samples. Plasma cortisol and DHEA levels did not differ among the 3 groups, whereas the plasma serotonin level was higher in the 24 hG group than that in the other groups. The plasma cortisol to DHEA ratio was lower in the 24 hG group than that in the control and 12 hG group. The hair samples taken at the end of the experiment showed that the cortisol level was significantly higher in the control group than that in both of the grazing groups and also higher in the 12 hG than that in the 24 hG group. Hair DHEA and serotonin levels were highest in the 24 hG group. The hair cortisol to DHEA ratio was significantly higher in the control group than that in the 12 hG and 24 hG groups and in the 12 hG group than that in the 24 hG group. Our study showed that grazing dairy cows in alpine areas for 24 h improved their welfare, as indicated by increased serotonin levels in hair and plasma, increased hair DHEA level, and decreased stress indicators, including the hair cortisol level and cortisol to DHEA ratio. Farm facilities should allocate optimal grazing time for optimal welfare of dairy cows.
通过对血液和毛发样本的分析，本研究评估了高寒地区放牧对奶牛福利指标和应激指标的影响。21头荷斯坦奶牛（体重：637±21.5千克；产奶天数：133±17.7天，二胎）被随机分为3组：对照组（不放牧）、12小时高寒放牧组（12hG）和24小时高寒放牧组（24hG）。在实验结束时连续3天采集用于血浆采集的血样。在实验开始和结束时采集毛发样本。激素测量包括血浆和毛发样本中的皮质醇、血清素和脱氢表雄酮（DHEA）。3组之间血浆皮质醇和DHEA水平无差异，而24hG组的血浆血清素水平高于其他组。24hG组的血浆皮质醇与DHEA比值低于对照组和12hG组。实验结束时采集的毛发样本显示，对照组的皮质醇水平显著高于两个放牧组，12hG组的皮质醇水平也高于24hG组。毛发DHEA和血清素水平在24hG组中最高。对照组的毛发皮质醇与DHEA比值显著高于12hG组和24hG组，12hG组的该比值高于24hG组。我们的研究表明，在高寒地区放牧24小时可改善奶牛的福利，表现为毛发和血浆中血清素水平升高、毛发DHEA水平升高以及应激指标降低，包括毛发皮质醇水平和皮质醇与DHEA比值。农场设施应分配最佳放牧时间以实现奶牛的最佳福利。
