Forms of leg abnormality observed in male broilers fed on a diet containing 12.5 percent rapeseed meal

The incidence of leg abnormalities was studied in 216 male Ross I broilers, fed for 10 weeks on a diet containing 12.5 per cent extracted rapeseed. Regular serological examination showed that the birds remained free from Mycoplasma gallisepticum, Mycoplasma synoviae and avian reovirus throughout the period of investigation. Post mortem examination and radiographs were performed when birds were culled due to leg deformities or at the end of the experiment. Leg abnormalities were seen in 19.4 per cent of the birds which represents a very significant increase above that currently seen in commercial flocks. They consisted of a large range of skeletal deformities including valgus and varus deformities, dyschondroplasia, slipped gastrocnemius tendons, dislocated condyles, rotation and penetration of the distal tibiotarsus and fractured fibulas. Multiple forms of leg abnormality were often observed in individual birds and their association is briefly discussed.