VARIANCE COMPONENT ESTIMATES OF SOME BOAR SEMEN CHARACTERISTICS AND THEIR USE IN DESIGNING EXPERIMENTS

Summary. Semen records of ten ejaculates from each of ten Yorkshire boars were used to estimate the boar and ejaculate variance components for eleven semen characteristics. These data were used to estimate the power of the test. In ten of eleven characteristics, a minimum of five boars and five ejaculates per boar provided at least a 90% chance of detecting a difference of 50% of the mean. For these same ten characteristics, a minimum of fourteen boars and forty-three ejaculates per boar provided at least a 90% chance of detecting a difference of 25% of the mean.