Agnvall B, Ali A, Olby S, Jensen P
IFM Biology,Avian Behavioural Genomics and Physiology Group,Linköping University,581 83 Linköping,Sweden.
Animal. 2014 Sep;8(9):1498-505. doi: 10.1017/S1751731114001426. Epub 2014 Jun 9.
Many traits associated with domestication are suggested to have developed as correlated responses to reduced fear of humans. Tameness may have reduced the stress of living in human proximity and improved welfare in captivity. We selected Red Junglefowl (ancestors of all domestic chickens) for four generations on high or low fear towards humans, mimicking an important aspect of the earliest period of domestication, and tested birds from the third and fourth generation in three different social tests. Growth and plumage condition, as well as size of eggs and offspring were also recorded, as indicators of some aspects of welfare. Birds selected for low fear had higher weight, laid larger eggs and generated larger offspring, and had a better plumage condition. In a social dominance test they also performed more aggressive behaviour and received less of the same, regardless of whether the restricted resource was feed or not. Hence, dominance appeared to increase as a consequence of reduced fear of humans. Furthermore, egg size and the weight of the offspring were larger in the less fearful birds, and plumage condition better, which could be interpreted as the less fearful animals being better adapted to the environment in which they were selected.
许多与驯化相关的特征被认为是作为对减少对人类恐惧的相关反应而发展起来的。温顺可能减轻了生活在人类附近的压力，并改善了圈养环境中的福利。我们对红原鸡（所有家鸡的祖先）进行了四代选育，根据对人类的恐惧程度分为高恐惧组和低恐惧组，模拟驯化早期的一个重要方面，并在三种不同的社交测试中对第三代和第四代的鸡进行了测试。还记录了生长和羽毛状况，以及蛋和后代的大小，作为福利某些方面的指标。被选作低恐惧的鸡体重更高，产蛋更大，后代也更大，并且羽毛状况更好。在社会优势测试中，无论受限资源是否为食物，它们也表现出更多的攻击行为，且受到的同类攻击更少。因此，由于对人类恐惧的减少，优势地位似乎有所增加。此外，恐惧程度较低的鸡所产蛋的大小和后代的体重更大，羽毛状况更好，这可以解释为恐惧程度较低的动物更能适应它们被选育的环境。
