Impact of addition of new herds on genetic parameter estimates in the Australian Brahman population

Abstract

The impact of new herds joining BREEDPLAN in recent years was investigated by comparison of genetic parameters estimated from old and new herds over the same time period. New herds tended to be smaller than older herds, but no difference was observed in average contemporary group size between the two groups. Some difference was observed between the two groups in direct genetic and residual variances, most likely due to less information available from new herds. Despite these differences, genetic parameters for the trait of 200-day weight for the two groups were very similar, indicating the data could be successfully combined for genetic evaluation purposes.