Dehydration and lameness in a broiler flock

A case study is described in which a high incidence of lameness in broiler chickens (Gallus gallus domesticus) is associated with rearing to 84 days of age; broilers are normally slaughtered at less than 50 days of age. A sample of 185 birds was scored for walking ability, and 24 birds from this group were assessed for dehydration by measuring plasma osmolality. The proportion of the group having gait abnormalities was compared with that recorded during a recent survey of Danish flocks and was found to be higher. A relationship is established between the degree of gait impairment and the level of dehydration. The degree of dehydration is related to the findings for plasma osmolality from previous research, and the results indicate that some of the birds in this case may have been deprived of access to water for periods in excess of 60 hours.