CLAW LESIONS IN DAIRY-CATTLE - DEVELOPMENT OF SOLE AND WHITE LINE HEMORRHAGES DURING THE FIRST LACTATION

The development of claw haemorrhages was monitored in first-calving da iry heifers from 4 weeks before calving to 32 weeks after calving. Bef ore calving, lesions were few but the number, extent and severity of c law haemorrhages increased following simultaneous calving and housing. Lesions were most severe in the white line at 9 weeks, and in the sol e at 14 weeks, but recovery began while the animals were still housed. That the increase in white line lesions after calving, and the subseq uent recovery preceded that of the sole, suggests that the pathogenesi s of the lesions may differ in these two anatomical regions. It is pro posed that an initial insult to the cerium primarily affects the lamin ar region and that cerium damage increases with the resulting alterati on in the physical forces on the sole.