Dominance relationships among previously undernourished and well fed male rats.

WHATSON, T. S., J. L. SMART AND J. DOBBING. Dominance relationships among previously undernourished and well fed male rats. PHYSIOL. BEHAV. 14(4)425-429, 1975. Experimental rats were growth retarded by underfeeding their mothers during pregnancy and lactation. All rats were fed ad lib from weaning. Pairs of previously undernourished (PU) and control (C) males were housed together from 30 or 80 days. Social behavior within these groups was observed at about 175 days. PU rats submitted to other PU rats more frequently than indicated by the null hypothesis and C rats allogroomed PU rats less frequently. Some of these groups were divided into pairs comprising one C and one PU rat. In a water-spout competition situation, thirsty PU rats were rather more successful than controls in that they tended to possess the water-spout longer. The rats were then separated and after one week of isolation were reunited in an observation box for 10 rain a day on 4 successive days. PU rats allogroomed and walked over or crawled under C rats more frequently. In general, PU rats were the more likely to be the active partners in social encounters, with C rats assuming a passive role.