School of Biology, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia.
Animal Behaviour and Welfare Team, Scotland's Rural College, West Main Road, Kings Buildings, Edinburgh EH9 3JG, UK.
Animal. 2023 Nov;17(11):101006. doi: 10.1016/j.animal.2023.101006. Epub 2023 Oct 5.
It is common in many countries for sheep to be housed during winter from mid-gestation until lambing to protect ewes and lambs from adverse conditions and improve late gestation nutritional management. Keeping ewes indoors, however, has its own challenges as the animals may be mixed with unfamiliar conspecifics, have limited floor and feeding space, experience changes to their diet and increased handling by humans. Therefore, the objective of this study was to investigate the effect of variation in housing management (space allowance and social stability) on the behaviour and hypothalamic-pituitary-adrenal (HPA) axis responses of pregnant ewes from mid-to-late gestation (weeks 11-18 of pregnancy). Seventy-seven ewes (41 primiparous, 36 multiparous) were divided into two groups: 'Control' and 'Restricted space and mixed' (RS-Mix), where RS-Mix ewes were allocated half the amount of space (1.27 vs 2.5 m for RS-Mix and Control, respectively) and feedface (concentrate feeder space) allowance (36 vs 71 cm per ewe) given to the Control group and were also subjected to two social mixing events. Aggressive behaviour at the feedface and time spent standing, lying, walking, feeding and ruminating were recorded and faecal samples were collected for assessment of faecal glucocorticoid metabolite (FGM) concentrations. Higher aggression was observed in RS-Mix ewes during the first week of observation (P = 0.044), which gradually declined to the same level as Control ewes by the end of the study (P = 0.045). RS-Mix ewes were significantly less likely to be able to freely join the feedface compared to Controls (P = 0.022). No other significant treatment effects on aggressive behaviour or FGM during gestation were found. RS-Mix ewes displayed significantly higher ruminating behaviour at week 18 of gestation compared to Control ewes (P < 0.001), but no other effects were seen on general pen behaviour. However, the effect of indoor housing had a significant impact on primiparous ewes, who had lower weight gain (P = 0.015) and higher FGM concentrations (P = 0.014) compared to multiparous ewes regardless of treatment group. The data suggest that, although no sustained effects on behaviour or HPA axis responses were seen with the differences in space and feeder allowance or social stability at the levels used in this study, inexperienced (primiparous) ewes may find indoor housing more stressful; and are less able to adapt compared to multiparous ewes. These effects may influence the behaviour of the ewe at lambing time, and her offspring.
在许多国家，为了保护母羊和羔羊免受恶劣条件的影响并改善妊娠后期的营养管理，通常会让绵羊在妊娠中期到产羔期间被圈养在室内。然而，让母羊在室内饲养也存在一些挑战，因为这些动物可能会与不熟悉的同种动物混养，活动空间和饲料空间有限，饮食也会发生变化，并且会受到更多的人为干扰。因此，本研究的目的是调查饲养管理（空间分配和社会稳定性）的变化对妊娠中期至后期（妊娠 11-18 周）母羊的行为和下丘脑-垂体-肾上腺（HPA）轴反应的影响。77 只母羊（41 只初产，36 只经产）分为两组：“对照”和“限制空间和混合”（RS-Mix），其中 RS-Mix 组的母羊分配到一半的空间（RS-Mix 和对照分别为 1.27 和 2.5 m）和饲料采食区（浓缩饲料采食区）面积（每只母羊 36 厘米对对照的 71 厘米），并且还进行了两次社交混合。记录了在饲料采食区的攻击行为以及站立、躺卧、行走、采食和反刍的时间，并采集粪便样本以评估粪便皮质酮代谢物（FGM）浓度。在观察的第一周，RS-Mix 组的母羊表现出更高的攻击性（P=0.044），但到研究结束时，攻击性逐渐下降到与对照相同的水平（P=0.045）。与对照组相比，RS-Mix 组的母羊在自由加入饲料采食区的可能性明显较低（P=0.022）。在妊娠期间，没有发现饲养管理对攻击行为或 FGM 有其他显著影响。与对照组相比，RS-Mix 组的母羊在妊娠第 18 周的反刍行为显著增加（P<0.001），但在一般围栏行为方面没有其他影响。然而，室内饲养的影响对初产母羊有显著影响，无论处理组如何，初产母羊的体重增加（P=0.015）和 FGM 浓度（P=0.014）都较高。数据表明，尽管在本研究中使用的空间和饲料分配或社会稳定性的差异没有对行为或 HPA 轴反应产生持续影响，但经验不足的（初产）母羊可能会发现室内饲养的压力更大；并且与经产母羊相比，它们适应的能力较差。这些影响可能会影响母羊在产羔时的行为及其后代的行为。
