Abstract
The effects of group size (individually versus 3 in a cage) and gentling on behaviour and blood constituents were studied in female rats. Gentled rats showed less freezing and/or escaping when approached in an objective handling test than non-gentled rats; the type of caging had no significant influence. In a small field, gentled rats displayed significantly more turning and standing upright, whereas these parameters did not differ between rats housed either individually or three in a cage. In both tests, gentled rats produced significantly less urine than did control rats. Neither caging nor gentling significantly influenced the group mean values and variance of masses of adrenals, spleen and thymus and plasma concentrations of glucose, cholesterol, triglycerides and corticosterone. Removal of a cage from the rack and getting out a rat caused increase in plasma concentrations of corticosterone in its remaining cage mates.