Boumans Iris J M M, de Boer Imke J M, Hofstede Gert Jan, Bokkers Eddie A M
Animal Production Systems group, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Animal Production Systems group, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Physiol Behav. 2018 Jul 1;191:100-115. doi: 10.1016/j.physbeh.2018.03.030. Epub 2018 Apr 7.
Domesticated pigs, Sus scrofa, vary considerably in feeding, social interaction and growth patterns. This variation originates partly from genetic variation that affects physiological factors and partly from behavioural strategies (avoid or approach) in competitive food resource situations. Currently, it is unknown how variation in physiological factors and in behavioural strategies among animals contributes to variation in feeding, social interaction and growth patterns in animals. The aim of this study was to unravel causation of variation in these patterns among pigs. We used an agent-based model to explore the effects of physiological factors and behavioural strategies in pigs on variation in feeding, social interaction and growth patterns. Model results show that variation in feeding, social interaction and growth patterns are caused partly by chance, such as time effects and coincidence of conflicts. Furthermore, results show that seemingly contradictory empirical findings in literature can be explained by variation in pig characteristics (i.e. growth potential, positive feedback, dominance, and coping style). Growth potential mainly affected feeding and growth patterns, whereas positive feedback, dominance and coping style affected feeding patterns, social interaction patterns, as well as growth patterns. Variation in behavioural strategies among pigs can reduce aggression at group level, but also make some pigs more susceptible to social constraints inhibiting them from feeding when they want to, especially low-ranking pigs and pigs with a passive coping style. Variation in feeding patterns, such as feeding rate or meal frequency, can indicate social constraints. Feeding patterns, however, can say something different about social constraints at group versus individual level. A combination of feeding patterns, such as a decreased feed intake, an increased feeding rate, and an increased meal frequency might, therefore, be needed to measure social constraints at individual level.
家猪（Sus scrofa）在进食、社交互动和生长模式方面存在很大差异。这种差异部分源于影响生理因素的基因变异，部分源于在竞争性食物资源情况下的行为策略（回避或接近）。目前，尚不清楚动物之间生理因素和行为策略的差异如何导致动物在进食、社交互动和生长模式上的差异。本研究的目的是揭示猪群中这些模式差异的成因。我们使用基于主体的模型来探究猪的生理因素和行为策略对进食、社交互动和生长模式差异的影响。模型结果表明，进食、社交互动和生长模式的差异部分是由偶然因素造成的，比如时间效应和冲突的巧合。此外，结果表明，文献中看似矛盾的实证研究结果可以通过猪的特征差异（即生长潜力、正反馈、优势地位和应对方式）来解释。生长潜力主要影响进食和生长模式，而正反馈、优势地位和应对方式则影响进食模式、社交互动模式以及生长模式。猪之间行为策略的差异可以在群体层面减少攻击行为，但也会使一些猪更容易受到社会限制，抑制它们在想吃东西时进食，尤其是地位较低的猪和具有被动应对方式的猪。进食模式的差异，如进食速度或进餐频率，可以表明社会限制。然而，进食模式在群体层面和个体层面所反映的社会限制可能有所不同。因此，可能需要综合多种进食模式，如采食量减少、进食速度增加和进餐频率增加，来衡量个体层面的社会限制。
