Abstract
The one-stage prothrombin times of 100 lambs from ten different farms varied from 13 to 24 seconds with a mean of 16.6 seconds. The extent and severity of subcutaneous haemorrhagic speckling of carcases was assessed in 775 animals from the same farms and the prevalence of this lesion was similar to that found at the same works during the 1977/78 season. The means of both one-stage prothrombin times and speckling varied significantly between groups of Iambs from different farms but there was no statistical association between the prevalence of speckling and the one-stage prothrombin times.