Sole haemorrhages in tied heifers in early gestation as an indicator of laminitis: effects of diet and flooring.

The influence of feeding a high concentrate diet and of different types of floor surface on the prevalence and severity of haemorrhages of the sole horn was studied in 60 Swedish Friesian heifers during early pregnancy. For 4 weeks, out of a total observation period of 17 weeks, half the animals were offered 6.5 kg/day of concentrates while the others were fed a standard diet consisting mainly of roughage. Half the animals were kept on rubber mats and half on a concrete floor. The hooves were trimmed and the soles were photographed at the start and at the end of the experiment. The photographs were evaluated, each claw was scored for sole haemorrhages, and the total score for all 8 claws was calculated. No differences were observed between the groups in the scores of sole haemorrhages at any trimming. The scores were significantly higher at the first than at the second trimming, probably as a consequence of an abrupt change of floor surface 2-3 months before the first trimming. The study provides indirect evidence that events relating specifically to calving are likely to be crucial risk factors for sole haemorrhages and laminitis.