Achterberg E J Marijke, Baars Anne-Marie J M, van Hal Daphne A, Lesscher Heidi M B, Van Loo Pascalle L P
Department of Population Health Sciences, Unit of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
Animal Welfare Body Utrecht, Utrecht University, Bolognalaan 50, 3584 CJ Utrecht, The Netherlands.
Animals (Basel). 2025 Sep 22;15(18):2757. doi: 10.3390/ani15182757.
The legal minimum dimensions for laboratory rat housing prevent rats from fully performing their behavioural repertoire. In the regular cages, rats cannot run, climb, or even stand upright. The need to house rats in larger cages has been recognized internationally from a welfare perspective, which has led to the development of several commercial cage systems. It is, however, important to evaluate the effect of changes in housing conditions on behaviour in existing animal models. The aim of the study was to determine whether housing animals in larger cages with mandatory enrichment or with additional enrichment would affect play behaviour or sucrose reward sensitivity. This paper describes the effect of housing rats in enlarged cages, the EC4Rats, on social play and for reward seeking. A total of 48 male Lister Hooded rats, PND21-23 at the start of the experiment, were assigned to one of three experimental groups, i.e., (1) standard housing with standard enrichment, (2) EC4Rats housing with standard enrichment and (3) EC4Rats housing with EC4Rats enrichment. The results of the study show that despite subtle differences in social play behaviour, housing rats in these larger cages did not affect reward sensitivity nor the motivation for sucrose self-administration in rats. Taken together, these findings suggest that housing systems that provide rats with more opportunities to engage in natural behaviours do not affect social play or reward-related behaviour.
实验室大鼠饲养的法定最小尺寸限制了大鼠充分展现其行为表现。在常规笼子里，大鼠无法奔跑、攀爬，甚至无法直立。从动物福利角度来看，国际上已经认识到需要将大鼠饲养在更大的笼子里，这促使了几种商业笼具系统的开发。然而，评估现有动物模型中饲养条件的变化对行为的影响非常重要。本研究的目的是确定将动物饲养在配备强制性丰富设施或额外丰富设施的更大笼子里是否会影响玩耍行为或蔗糖奖励敏感性。本文描述了将大鼠饲养在扩大的笼子（EC4Rats笼）里对社交玩耍和奖励寻求的影响。总共48只雄性利斯特戴帽大鼠在实验开始时为出生后第21 - 23天，被分配到三个实验组之一，即：(1) 配备标准丰富设施的标准饲养组，(2) 配备标准丰富设施的EC4Rats笼饲养组，以及(3) 配备EC4Rats丰富设施的EC4Rats笼饲养组。研究结果表明，尽管社交玩耍行为存在细微差异，但将大鼠饲养在这些更大的笼子里不会影响奖励敏感性，也不会影响大鼠自我给予蔗糖的动机。综上所述，这些发现表明，为大鼠提供更多机会进行自然行为的饲养系统不会影响社交玩耍或与奖励相关的行为。
