Effects of restraint with or without blinds at the feed barrier on feeding and agonistic behaviour in horned and hornless goats

Abstract

The strict dominance hierarchy in goats bears the risk of low-ranking goats not getting adequate access to feed, especially for goats in small groups. The aim of our study was to test the effect of restraint in headlocks with and without blinds at the feed barrier on feeding and agonistic behaviour in horned and hornless goats. A total of 54 non-lactating dairy goats kept in 8 groups (4 horned, 4 hornless), was tested with 4 variants of the feed barrier (blinds yes/no, restraint in headlocks yes/no) in a 2×2-factorial design. Each variant was applied to each group for 5–6 weeks with an animal-to-feeding-place ratio of 1:1. Agonistic interactions and feeding behaviour were observed during the first hour after each of the two daily feed deliveries, and feeding behaviour was recorded additionally from 0:00h to 5:00h (night-time feeding). Data were analysed using generalised linear mixed-effects models separately for horned and hornless goats.In horned goats, feeding duration was longer when goats were restrained in headlocks during feeding than when they were unrestrained, and this effect was reinforced with blinds present (restraining×blinds P=0.01). Only when restrained, low-ranking goats fed nearly as long as high-ranking goats (restraining×rank index P<0.0001). Horned goats were feeding for a considerable amount of time during the night; the lower the rank the more night-time feeding was observed (P=0.002). In hornless goats, feeding duration was also longer when goats were restrained compared to being unrestrained, and this effect was largest in low-ranking hornless goats (restraining×rank index P<0.0001). Blinds had no additional effect. Feeding during the night was observed at a low level, and no significant effect of either rank or feed barrier variants was found. Agonistic interactions with physical contact were at a low level in horned goats when they had unrestrained access to feed and when they were restrained with blinds, but agonistic interactions were increased when horned goats were restrained without blinds (restraining×blinds P=0.001). In hornless goats, agonistic interactions with contact were reduced only when being restrained with additional blinds present (restraining×blinds P<0.001). Neither variant of the feed barrier nor rank index significantly affected body weight changes, regardless of horn status. In conclusion, restraint enabled all individuals of a herd to feed immediately after feed delivery. But when goats were restrained in the feed barrier, blinds between adjacent feeding places were necessary to prevent agonistic interactions with physical contact.