Effect of different pasture species on welfare and behavior of slow-growing broiler chickens in free-range production system

This study investigated the effect of various pasture species on the welfare and behavior of slow-growing broiler chickens in the free-range production system. After 21 days completely indoors, the birds were permitted access to outdoor pens cultivated with one of the following pasture treatments: Medicago sativa (A), Trifolium repens (WC), Lolium perenne (PR), and a mixture (Mix, A + WC + PR). The range availability was restricted between 08:30 and 16:30 daily. It was found that pasture type had a significant effect on the fluctuating asymmetry of the face and radius length ( P < 0.01). Duration of tonic immobility and blood parameters did not differ among the pasture species and between sexes at 11 weeks of broiler age ( P > 0.05). Pasture treatment had no significant effect on broiler behaviors ( P > 0.05). However, the age of broilers had a significant effect on pecking, dustbathing, and scratching ( P