Soede N M, Roelofs J B, Verheijen R J E, Schouten W P G, Hazeleger W, Kemp B
Animal Sciences Group, Wageningen University, AH Wageningen, The Netherlands.
Reprod Domest Anim. 2007 Apr;42(2):135-42. doi: 10.1111/j.1439-0531.2006.00742.x.
In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic gilts were assigned to one of four treatments, namely, stress treatment during the follicular phase (n = 20), stress treatment during early pregnancy (n = 20), stress treatment during both phases (n = 21) and no stress treatment (n = 20). All gilts were housed individually, but gilts in the stress treatments had no opportunity for visual or physical contact with other gilts. Further, animals in a stress-treatment were grouped for half an hour at the start of the treatment and during the treatment period nose-sling and an unpredictable feeding scheme were applied regularly. The extent of stress was monitored using heart rate measurements, behavioural observations and saliva cortisol levels during nose-sling fixation. Of the 81 gilts, 93% showed oestrus and were inseminated. Of these, 93% were pregnant at day 35, having 17.9 +/- 0.3 ovulations and 15.6 +/- 0.3 foetuses. These parameters were not affected by treatment. The stress treatment during the follicular phase tended to shorten cycle length (stress: 20.8 +/- 0.20; control: 21.2 +/- 0.17 days, p = 0.07) and weight of foetuses at day 35 (stress: 4.47 +/- 0.08 g; no stress: 4.69 +/- 0.08 g, p = 0.06); stress during early pregnancy did not affect any of the reproduction parameters. Percentage stereotypic behaviour, heart rate and saliva cortisol levels varied greatly between animals and between days, but did not differ between the treatments. No relationships were found between any of the reproductive parameters and any of the stress parameters (heart rate, cortisol, stereotypic behaviour). These results indicate that the repeatedly applied acute stressors did not generate a chronic stress-response and that these stressors during the follicular phase and/or during early pregnancy did not affect reproductive processes. It is not clear how these findings relate to suggested effects of stress(ors) on reproductive performance in pig husbandry.
在养猪业中，应激被认为是繁殖性能受损的一个重要原因。因此，进行了一项实验，以量化卵泡期和/或妊娠早期反复应激源对后备母猪繁殖性能的影响。81头处于发情周期的后备母猪被分配到四种处理之一，即卵泡期应激处理（n = 20）、妊娠早期应激处理（n = 20）、两个阶段均进行应激处理（n = 21）和无应激处理（n = 20）。所有后备母猪均单独饲养，但接受应激处理的后备母猪没有机会与其他后备母猪进行视觉或身体接触。此外，在处理开始时，接受应激处理的动物被分组半小时，并且在处理期间定期采用鼻吊和不可预测的饲喂方案。在鼻吊固定期间，通过心率测量、行为观察和唾液皮质醇水平来监测应激程度。81头后备母猪中，93%表现出发情并接受了授精。其中，93%在第35天怀孕，排卵17.9±0.3个，有15.6±0.3个胎儿。这些参数不受处理的影响。卵泡期的应激处理倾向于缩短发情周期长度（应激组：20.8±0.20天；对照组：21.2±0.17天，p = 0.07）以及第35天胎儿的体重（应激组：4.47±0.08克；无应激组：4.69±0.08克，p = 0.06）；妊娠早期的应激对任何繁殖参数均无影响。刻板行为百分比、心率和唾液皮质醇水平在动物之间以及不同天数之间差异很大，但在各处理之间没有差异。在任何繁殖参数与任何应激参数（心率、皮质醇、刻板行为）之间均未发现相关性。这些结果表明，反复施加的急性应激源并未产生慢性应激反应，并且这些应激源在卵泡期和/或妊娠早期并未影响繁殖过程。尚不清楚这些发现与养猪业中应激（源）对繁殖性能的假定影响之间有何关联。
