Prevalence of claw lesions in Norwegian dairy cattle housed in tie stalls and free stalls.

Approximately 88% of Norwegian dairy cattle are housed in tie stalls. Free-stall housing will be implemented for all cattle within 20 years. This means that most existing barns have to be rebuilt in the near future. We designed our study to estimate the prevalence of claw lesions in Norway and to reveal possible differences between tie stalls and free stalls. Fifty-five tie-stall herds and 57 free-stall herds were sampled by computerized systematic selection and 2665 cows were trimmed by 13 claw trimmers, during the late winter and spring of 2002. The claw trimmers had been taught diagnosing and recording of claw lesions. Environmental factors, management and feeding routines also were recorded. Forty-eight percent of cows housed in tie stalls had one or more claw lesions versus 71.8% in free stalls. Prevalences recorded in the hind claws were: 4.2% of the animals had dermatitis in tie stalls versus 5.7% in free stalls; 7.9% versus 38.0% had heel-horn erosions; 7.3% versus 13.6% had haemorrhages of the white line; 11.7% versus 20.4% had haemorrhages of the sole; 2.8% versus 3.2% had sole ulcers and 5.5% versus 9.7% had white-line fissures. Most lesions were mild. A model was designed to estimate cluster effects within herd and within claw trimmer. The cluster effect within herd was significant for all lesions. The cluster effect within claw trimmer was only significant for heel-horn erosions in front and hind claws and for white-line fissures in front claws. Agreements between some of the claw lesions were revealed. The study confirms that in Norwegian dairy cattle, most claw lesions are more prevalent in free stalls than in tie stalls.