Coefficients of inbreeding and degree of relationship for the British Friesian herd

Abstract
The coefficients of inbreeding and the degree of relationship for British Friesian bulls used for artificial insemination by the Milk Marketing Board in sample years between 1955 and 1972 and for random samples of registered females from the same years have been calculated. The average coefficient of inbreeding was lower in bulls (0·5%) than in registered females (2·7%). The average degree of relationship was 0·7% for bulls and 2·6% for heifers.