Nagel Christina, Melchert Maria, Aurich Jörg, Aurich Christine
Graf Lehndorff Institute for Equine Science, Vetmeduni Vienna, Neustadt (Dosse), Germany.
Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni Vienna, Vienna, Austria.
J Equine Vet Sci. 2020 Mar;86:102894. doi: 10.1016/j.jevs.2019.102894. Epub 2019 Dec 23.
Cortisol is involved in the initiation of parturition and we hypothesized that increased maternal cortisol release advances the onset of foaling. Transport is a stressor for horses and induces an increase in cortisol release. To determine stress effects on the time of foaling, late-pregnant mares were transported by road for 3 hours (n = 12) or remained in their stable as controls (n = 4). Starting on day 325 of gestation, saliva and blood samples were taken for cortisol and progestin analysis, respectively. Fetomaternal electrocardiograms were recorded repeatedly. Mares were checked for impending parturition and changes in precolostrum pH. When pH decreased to 6.5, mares were either transported or left untreated. After birth, saliva was collected repeatedly from mares and their foals and heart rate (HR) was recorded. Foals were checked for maturity and health. Gestation length was 337 ± 2 days in stressed and 336 ± 2 days in control mares. Cortisol concentration increased from 3.3 ± 0.9 to 8.4 ± 0.8 ng/mL in transported mares (P < .001) and remained constant in controls. Maternal HR and heart rate variability (HRV) did not differ between groups and neither fetal HR nor HRV changed in response to transport. In transported mares, time from precolostrum decrease to parturition was shorter (40 ± 10 hours) than the respective time in controls (134 ± 49 hours, P < .01). Neither duration of foaling nor times to first standing and suckling of foals or the postnatum increase in HR and decrease in HRV differed between groups. In conclusion, transport-induced maternal cortisol release may have advanced the onset of foaling.
皮质醇参与分娩的启动，我们推测母体皮质醇释放增加会使产驹时间提前。运输对马匹来说是一种应激源，会导致皮质醇释放增加。为了确定应激对产驹时间的影响，将妊娠晚期的母马通过公路运输3小时（n = 12），或作为对照留在马厩中（n = 4）。从妊娠第325天开始，分别采集唾液和血液样本进行皮质醇和孕酮分析。反复记录母胎心电图。检查母马是否即将分娩以及初乳前pH值的变化。当pH值降至6.5时，对母马进行运输或不进行处理。出生后，反复从母马及其驹中采集唾液，并记录心率（HR）。检查驹的成熟度和健康状况。应激组母马的妊娠期长度为337±2天，对照组为336±2天。运输母马的皮质醇浓度从3.3±0.9 ng/mL增加到8.4±0.8 ng/mL（P <.001），而对照组保持不变。两组之间母体HR和心率变异性（HRV）没有差异，运输对胎儿HR和HRV也没有影响。在运输的母马中，从初乳前pH值下降到分娩的时间（40±10小时）比对照组（134±49小时，P <.01）短。两组之间产驹持续时间、驹首次站立和吮乳的时间，或产后HR增加和HRV降低均无差异。总之，运输诱导的母体皮质醇释放可能提前了产驹时间。
