Sole haemorrhages in tied primiparous cows as an indicator of periparturient laminitis: effects of diet, flooring and season.

Fifty-six tied heifers calving in autumn (trial I) and 21 tied heifers calving in late spring (trial II) were fed either a high or a low concentrate diet from 3 weeks before expected calving until 13 weeks after calving. Half the heifers in trial I were kept on concrete floors and the others were kept on rubber mats; all the heifers in trial II were on concrete floors. The hooves were trimmed and the soles were photographed 3 weeks before expected calving and again 13 weeks after calving. The photographs were evaluated, each claw was scored for sole haemorrhages, and the total score for all 8 claws was calculated. Before calving there were no differences between the groups of heifers within trial I or trial II, but the heifers in trial II had higher scores than those in trial I. Thirteen weeks after calving the scores had increased in both trials. In trials I the animals fed the high concentrate diet and kept on concrete floors had the highest score, and the type of floor had a greater influence than the level of concentrates fed. The heifers calving in the autumn had higher scores than those calving in the spring. The sudden change from being at pasture to being housed, and the events related to the periparturient period were the most significant factors for the development of sole haemorrhages.