Castration or sterilisation: a basic research oriented study to the effects of animal welfare and mate choice in guinea pigs

阉割或绝育：一项以动物福利和豚鼠配偶选择影响为导向的基础研究。应避免圈养动物不受控制的繁殖。为了达到这个目的，动物通常会被阉割，即生殖腺被完全切除。由于这一过程，有时动物表现出的不受欢迎的攻击性以及求爱和性行为也会减少。这些行为改变符合人类利益。然而，从动物的角度来看，问题出现了，绝育（一个强度小得多的过程，因为性腺没有被切除，只是阻止了卵子和精子细胞的运输）是否比阉割更好：与绝育相比，阉割减少了自然行为模式的表现。该项目是动物福利基础研究的一部分。总体目的是分析两种手术，阉割和绝育对动物福利的不同影响。这是在豚鼠身上进行的研究，因为在社会行为、社会组织和动物福利方面进行了全面的研究，所以豚鼠是一个非常合适的动物模型。我们将采用以下基本的实验策略：建立由一名男性和两名完整女性组成的小组，并将四组不同的男性进行比较：阉割，绝育，假手术和完整男性。此外，我们将调查与不同处理的雄性生活在一起的雌性。作为雄性和雌性动物福利的指标，我们将调查社会积极，激动和玩耍行为以及血浆皮质醇浓度。此外，我们将调查女性是否更喜欢绝育或阉割的男性。在这个项目中产生的数据，允许基于证据的决策的问题，手术（阉割或绝育）应该进行。因此，这个项目的结果将对如何处理圈养动物的问题做出至关重要的贡献。

Castration or sterilisation: a basic research oriented study to the effects of ani-mal welfare and mate choice in guinea pigsAn uncontrolled reproduction of animals kept in captivity should be avoided. To meet this goal generally animals are castrated, i.e. the gonads are completely removed. Because of this procedure, sometimes also undesirable aggressive as well as courtship and sexual behaviour displayed by the animals can be reduced. These behavioural changes are in human interest. From the animal´s point of view, the question arises, however, whether sterilisation (a much less intense procedure, since gonads not removed, but only the transport of egg and sperm cells are prevented) could be better than a castration: in contrast to a sterilisation, a castration reduced the display of natural behavioural patterns. The project is part of basic research regarding animal welfare. The overall aim is to analyse the different effects of the two operations, castration and sterilisation on animal welfare. This is investigated in guinea pigs, a very well suitable animal model because of comprehensive studies in social behaviour, social organisation and animal welfare. We will work with the following basic experimental strategy: Groups consisting of one male and two intact females will be established and four different groups of males will be compared: castrated, sterilized, sham-operated and intact males. Furthermore, we will investigate the females, living together with the different treated males. As indicator for animal welfare of males and females, we will investigate socio-positive, agonistic and play behaviour as well as plasma cortisol concentrations. Additionally we will investigate whether females prefer sterilized or castrated males. In this project data are generated, which allow evidence based decisions regarding the question which operation (castration or sterilisation) should be conducted. Thus, the results of this project will contribute crucially to the question how to handle animals in captivity.