Department of Animal Behaviour and Welfare, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, 05-552, Magdalenka, Poland.
Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-747, Olsztyn, Poland.
Theriogenology. 2022 Mar 1;180:82-86. doi: 10.1016/j.theriogenology.2021.12.018. Epub 2021 Dec 17.
Equine reproductive behavior is affected by many factors, some remaining poorly understood. This study tested the hypothesis that a period of captivity during the juvenile period and human-controlled reproduction may potentially be involved in the disruption of the development of incestuous mating avoidance behavior in sanctuary-reintroduced male Konik polski horses. Between 1986 and 2000, cases of incestuous behavior in harem stallions born and reared until weaning in the sanctuary were studied. Eight males lived in the sanctuary's feral herd for the rest of their lives (the non-captive group; nC). They gained their own harem of mares without human intervention (no human-controlled reproductive activity, nHC). Another five stallions were removed as weanlings, reared in captivity and then reintroduced as adults (captive, C). Three of these C stallions were used as in-hand breeding stallions, one as a "teaser" (human-controlled reproductive activity, HC) and one was not used for reproduction in captivity (nHC). Reproductive records for 46 mares, daughters of all 13 harem stallions, were scrutinized and cases of incestuous breeding were recorded by interrogation of foal parentage records. C stallions failed to expel more daughters than nC stallions (33% vs. 18%, P = 0.045), and mated with significantly more of them (28% vs. 11%, P = 0.025). Interestingly, HC stallions expelled fewer (60%) and successfully mated with more (33%) daughters that nHC stallions (84% expelled, P = 0.013, and 10% successful mating with daughters, P = 0.010). All HC stallions bred incestuously at least once. We propose that human intervention during a critical period of development of social and reproductive behavior in young stallions, by enforced separation from their natal herd and in-hand breeding, may contribute to their later aberrant behavior and disruption of inbreeding avoidance mechanisms in these stallions. The previous occurrence of human-controlled breeding may be one of the factors promoting incestuous behavior of stallions in natural conditions. The uninterrupted presence of stallions in their harems and herd member recognition may also play important roles in inbreeding avoidance in horses.
马的生殖行为受到许多因素的影响，其中一些因素仍知之甚少。本研究检验了这样一个假设，即在幼年时期被圈养和人类控制的繁殖可能会潜在地干扰保护区重新引入的雄性波兰马的乱伦交配回避行为的发展。1986 年至 2000 年间，研究了在保护区出生和饲养至断奶的后宫种马的乱伦行为。八只雄性在保护区的野生群中度过了余生（非圈养组；nC）。它们在没有人类干预的情况下获得了自己的母马后宫（没有人类控制的繁殖活动，nHC）。另外五匹种马作为断奶幼驹被带走，在圈养中饲养，然后作为成年马重新引入（圈养，C）。这 5 匹 C 种马中的 3 匹被用作手中繁殖种马，1 匹作为“挑逗者”（人类控制的繁殖活动，HC），1 匹在圈养中不用于繁殖（nHC）。对 46 匹母马的繁殖记录进行了仔细审查，这些母马是所有 13 匹后宫种马的女儿，通过询问幼驹的亲子关系记录，记录了乱伦繁殖的案例。C 种马没有比 nC 种马排出更多的女儿（33%比 18%，P=0.045），并且与更多的女儿交配（28%比 11%，P=0.025）。有趣的是，HC 种马排出的（60%）和成功交配的（33%）女儿比 nHC 种马少（84%排出，P=0.013，与女儿成功交配 10%，P=0.010）。所有 HC 种马都至少有一次乱伦繁殖。我们提出，在年轻种马的社会和生殖行为的关键发展时期，通过与它们的出生地群强制分离和手中繁殖进行人为干预，可能导致它们后来的异常行为，并破坏这些种马的近亲繁殖回避机制。以前发生的人为控制繁殖可能是促进自然条件下种马乱伦行为的因素之一。种马在后宫和群体成员识别中的不间断存在也可能在马的近亲繁殖回避中发挥重要作用。
