Captive breeding of peccaries is on the increase in neotropical countries. Few studies, however, have reported behavioural responses of wild animals under farmed conditions. Therefore, the aim of this study was to evaluate the effects of space allowance on the occurrence of social behaviour patterns on farmed collared peccary (Pecari tajacu). We observed three herds of collared peccaries each containing eight acquainted individuals. Using a 3 * 3 Latin square design, herds were allocated, in a random order, to one of the three experimental enclosures, each with a different size: 375, 750 and 1,500 m2 of total available area, each with three wooden shelters. We recorded all the occurrences of selected positive and agonistic behavioural patterns that occurred 90 min before and during feeding. Enclosure size had a significant effect on agonistic patterns of peccaries during feeding, in that more agonistic behaviour was observed in smaller spaces. We also found that shelter usage increased as space decreased. Differing space allowances, however, did not have an effect on the occurrence of positive interactions that were more frequent before compared to during feeding. We concluded that enclosure size had an effect on the expression of agonistic behaviours and the use of shelters by collared peccaries. Thus, animal welfare can be improved by adopting at least 187.5 m2 per peccary. In addition, our study also confirmed the importance of shelter areas in collared peccary husbandry.