The influence of the cleanliness of cows' stalls on the cows' own cleanliness and on the health of their hooves was investigated in 52 dairy cows tied in stalls with long stanchions from 2 October 1989 to 7 May 1990 in one Swedish dairy herd. Twenty-six of the cows were provided with electric cow trainers throughout this period, 14 did not have trainers and 12 had trainers only for the period between 7 February and 7 May. The hooves of the hind feet were evaluated for Dermatitis interdigitalis (interdigital dermatitis) and Erosio ungulae (heel-horn erosion) on 2 October, 7 February and 7 May, and on this last occasion the dry matter content of the sole horn was measured. The average number of cow-pats deposited on the floors of the stalls with electric trainers was less than one-third of the number in the stalls without them, and the cows in stalls with trainers were approximately 30% cleaner. Between October and February, heel-horn erosion increased significantly only in the cows without electric trainers, and between February and May, heel-horn erosion decreased only in the cows which were provided with trainers on 7 February. The prevalence of interdigital dermatitis decreased in all the cows throughout the period of housing and there was no significant difference in prevalence between the different groups. The dry matter content of the sole horn was significantly greater in the cows which had electric trainers than in the cows without trainers, and the difference was significant even in the cows which had the trainers only from February to May. There was a significant negative correlation between the dry matter content of the sole horn and the level of heel-horn erosion.
