Sirovnik Janja, Simon Rebecca, Vogt Anina, Barth Kerstin, Smith Steve, Waiblinger Susanne, Lühken Gesine, König von Borstel Uta
Clinical Department for Farm Animals and Food System Science, Centre for Animal Nutrition and Welfare, University of Veterinary Medicine, Vienna, Austria.
Animal and Pathogenetics, Department of Animal Breeding and Genetics, Justus Liebig University Giessen, Giessen, Germany.
PLoS One. 2025 Mar 17;20(3):e0319156. doi: 10.1371/journal.pone.0319156. eCollection 2025.
Telomere length (i.e., the length of the repeated sequences of DNA at the end of chromosomes) is a promising indicator of overall stress. Our study aimed to compare the effects of a stress-inducing separation process between dams and their calves, with either a gradual or a nose-flap separation method after a three-months dam-calf contact since calving, on relative telomere length (RTL). Due to their nature, the nose-flap and gradual separation method have different effects on behaviour, stress hormone levels and physical development during and after dam-calf separation, which requires an overall measure of the weaning and separation stress during both procedures. We also investigated correlations between behavioural and other physiological stress indicators on RTL. We found no significant effect of the weaning and separation method on RTL in dairy calves after weaning and separation from their dams, but a tendency for shorter RTL in gradually separated dams compared to nose-flap separated dams. No correlations between behavioural and other physiological stress indicators and RTL were found, which may be due to a short interval between the two RTL measurement points. Future studies should aim to analyse the effect of various separation methods over a longer period and preferably include a non-separation group as reference.
端粒长度（即染色体末端DNA重复序列的长度）是一个很有前景的整体应激指标。我们的研究旨在比较产犊后三个月母犊接触后，采用逐渐分离法或鼻瓣分离法对母犊进行应激诱导分离过程，对相对端粒长度（RTL）的影响。由于鼻瓣分离法和逐渐分离法的性质不同，在母犊分离期间及之后，它们对行为、应激激素水平和身体发育有不同影响，这就需要对两种方法中的断奶和分离应激进行全面衡量。我们还研究了行为和其他生理应激指标与RTL之间的相关性。我们发现，断奶并与母犊分离后，断奶和分离方法对奶牛犊牛的RTL没有显著影响，但与鼻瓣分离的母犊相比，逐渐分离的母犊有RTL较短的趋势。未发现行为和其他生理应激指标与RTL之间存在相关性，这可能是由于两个RTL测量点之间的间隔较短。未来的研究应旨在分析更长时间段内各种分离方法的影响，并且最好纳入一个不分离组作为对照。
