Heidler B, Aurich J E, Pohl W, Aurich Chr
Clinic for Obstetrics, Gynecology and Andrology, University of Veterinary Sciences, Vienna, Austria.
Theriogenology. 2004 Apr 1;61(5):883-93. doi: 10.1016/s0093-691x(03)00279-6.
This study summarizes weight development, plasma glucose concentrations and reproductive parameters in lactating (n = 46) and non-lactating Lipizzaner mares (n = 11) throughout the breeding season. It was the aim of the study to analyse if an energy deficit with possible effects on reproductive functions occurs at any time during the first 4 months of gestation. Mean gestation length was 334.3 +/- 7.3 days. Gestation of foals born in May/June was shorter (P < 0.01) than for foals born in March/April. Out of the 46 lactating mares, 44 ovulated between Days 8 and 18 postpartum and two mares ovulated on days 30 and 145, respectively. Pregnant mares were significantly (P < 0.001) heavier (600.1 +/- 5.3 kg) than non-pregnant mares (521.8 +/- 10.0 kg) at the beginning of the study. Birth resulted in weight reduction of 64.8 +/- 2.4 kg. During the first 2 weeks postpartum mares lost on average 3.0 +/- 1.8 kg and in the following 2 weeks gained 3.6 +/- 1.4 kg of weight. Thereafter, weight increased slightly but continuously (P < 0.01). At no time after foaling, weight differed significantly between groups. Weight of the foals three days after birth varied between 29 and 67 kg (53.7 +/- 1.1 kg). Average daily weight gain of foals was relatively constant throughout the study period (1.15 +/- 0.17 kg). Although lactation at no time was associated with a major weight loss, it had clear effects on energy metabolism as shown by constantly lower plasma glucose concentrations in lactating mares. Glucose concentrations decreased after foaling and were significantly lower in lactating mares from Weeks 3 to 16 after foaling than at corresponding times in non-lactating mares (P < 0.01). However, glucose concentrations were still within the physiological range. Mares seem to be able to compensate energy losses during lactation mainly by increasing feed intake and not by mobilisation of body fat.
本研究总结了整个繁殖季节泌乳（n = 46）和非泌乳利皮扎马（n = 11）的体重变化、血浆葡萄糖浓度及繁殖参数。本研究的目的是分析在妊娠的前4个月内是否会出现对生殖功能可能有影响的能量不足。平均妊娠期为334.3±7.3天。5月/6月出生的驹的妊娠期比3月/4月出生的驹短（P < 0.01）。在46匹泌乳母马中，44匹在产后第8至18天排卵，两匹母马分别在第30天和第145天排卵。在研究开始时，怀孕母马（600.1±5.3 kg）比未怀孕母马（521.8±10.0 kg）显著更重（P < 0.001）。分娩导致体重减轻64.8±2.4 kg。产后前2周母马平均体重减轻3.0±1.8 kg，在接下来的2周内体重增加3.6±1.4 kg。此后，体重略有但持续增加（P < 0.01）。产后任何时候，两组之间的体重均无显著差异。出生三天后驹的体重在29至67 kg之间（53.7±1.1 kg）。在整个研究期间，驹的平均日增重相对恒定（1.15±0.17 kg）。虽然泌乳在任何时候都与体重的大幅减轻无关，但如泌乳母马血浆葡萄糖浓度持续较低所示，它对能量代谢有明显影响。产后葡萄糖浓度下降，泌乳母马在产后第3至16周的葡萄糖浓度显著低于非泌乳母马在相应时间的浓度（P < 0.01）。然而，葡萄糖浓度仍在生理范围内。母马似乎能够主要通过增加采食量而非动员体脂来补偿泌乳期间的能量损失。
