Bull-to-cow ratios: practical formulae for estimating the number of bulls suggested for successful pasture breeding of female cattle

Abstract

The literature contains inconsistent recommendations for bull-to-cow ratios used for pasture breeding in restricted breeding seasons. Age of bulls and scrotal circumference are primary determinants when bulls are classified as satisfactory potential breeders according to the standards of the Society for Theriogenology. The Auburn formulae are, for single-sire units, based on the bull’s age in months for young bulls, and on scrotal circumference in centimeters for adult bulls. The formula for multiple sire breeding groups also establishes a firm recommendation for larger breeding groups.