Dystocia in nine British breeds of cattle and its relationship to the dimensions of the dam and calf

Department of Clinical Veterinary Medicine, University of Cambridge.

The degree of assistance provided at 1353 calvings from 954 heifers and cows of nine breeds of British cattle (Ayrshire, British White, Dexter, Friesian/Holstein type, Gloucester, Kerry, Longhorn, Shetland and White Park) was recorded and analysed in terms of the dimensions of the dam and the calf. The sires had been chosen in accordance with normal farming practice. A heavy calf did not lead to dystocia. Assistance at calving was most frequently provided in the Ayrshire herd, which was used for veterinary teaching. There were very few difficult calvings in the seven rare breeds, but this was as likely to have been due to management policy as to the breed characteristics. A large tuber coxae measurement was associated with ease of calving, particularly in the Dexter. The breeds showed a wide range of pelvic dimensions and therefore provide a source of genetic variation.