Let me sleep! Welfare of broilers (Gallus gallus domesticus) with disrupted resting behaviour

Perching is important for broiler welfare, however, hampered by body weight. In a mixed flock, resting behaviour and location were compared between three broiler hybrids (Rowan Ranger, Hubbard CYJA57 & Ross 308; n=100/hybrid), differing in growth. Rearing was in a large littered pen (1.84 birds/m(2)), with perches. Behaviour and position was observed in focal birds on daytime and as group scans on daytime (days 11, 45, 61 and 80) and night-time (days 63, 70 and 77). Birds were slaughtered at 84 days and accumulated mortality in fast-growing birds was 20% and 2% in slow-growing. Resting frequency did not differ though fast-growing broilers perched less and lower, at night (P<.01) and day (P<.01). On daytime, males disturbed birds resting on the floor more than females did (P<.05). Disrupted rest is a potential welfare issue in broilers, hence perches or other elevated structures would improve welfare.