Perch use by broiler breeders and its implication on health and production
Broiler breeders are commonly kept without perches, although perching has been shown to be a high-priority behavior in laying hens. We studied whether broiler breeders used elevated perches of different lengths during the night and how access to perches affected health and production. Using the Ross 308 hybrid, pens offering 4 different perch spaces per bird (5, 10, 14, and 20 cm) in a cross-over design were compared with pens without perches. The number of birds on perches at midnight were recorded 7 times during production. Prevalence of keel bone fractures, breast blisters, pododermatitis, and plumage quality of hens was assessed at 45 wk, and production was monitored daily. To determine subsequent effects on offspring, chicks from hens with and without perches were reared and their growth rate was assessed. Analysis found more broiler breeders perched at night when 14 cm perch length per bird was provided than with less available perch length (P = 0.0005), but there was no difference between 14 and 20 cm per bird. Perch use declined with age from about 50 to 20% (P < 0.0001). The number of eggs and hatchability were not affected by treatment. During a period of high temperatures, mortality was lower in pens with perches (P = 0.001). Keel bone fractures were present in 1/4 of hens and were not affected by the presence of perches. The growth of chicks was not affected by the parent treatment. In conclusion, our results suggest that perches were chosen for roosting by broiler breeders depending on their age and did not impair production.