The experimental Animal in Biomedical Research (Vol. II) - Care, Husbandry, and Well-Being: Sheep (1995)

Fraser, A. F.

Abstract

Probably more than other species, they [sheep] require social company in order to cope with the circumstances of their domestication and in particular with the confinement under an experimental situation. It therefore follows that, in accommodating these animals for purposes of experimentation, their social needs should be given full consideration, on a par with other well-recognized physical needs such as nutrition, hygiene, and shelter. .. The socializing of animals [in metabolism crates] by animal technicians should be seen as a significant and regular component of the duties of such persons. Not only does this provide an alternative form of social contact for the animal, but also it modifies the reactions of the animal suitably; when later handling is to be done in the course of experimentation, the animal responds with less difficulty to the investigator. The anomalous behavior of wool picking or wool pulling is sometimes encountered among sheep kept in confinement under conditions of indoor crowding (see Figs 5 & 6). The condition takes the form of sheep pulling strands of wool from the fleece of neighbors, with their mouths. At first, the wool puller takes wool from the back of another sheep, but in time all areas of the body become denuded in victims, of which there may be several within one group. Most victims apper to have low postions in the social hierarchy of the group, but some victims are also wool pullers themselves. The causes appear to be compound, involving strssors in social crowding, lack of bulk in the diet, and lack of outdoor freedom to move and graze. .. This anomalous behavior is a clear sign of stressful indoor husbandry. Control lies in reduction of stocking density and isolation of any wool puller. This condition also indicates that sheep require consideration of social principles to be incorporated in their husbandry under conditions of biomedical use, in particular. Polydipsia nervosa is observed occasionally in sheep kept under close constraint, such as in metabolism crates or stalls.