Implications of selection for secondary traits on MOET-nucleus cattle breeding programs for dairy and dual-purpose breeds

Abstract

The objectives of this study were to examine the effects of incorporating secondary traits in a MOET-nucleus breeding scheme on genetic trend, profit and costs for both a dairy and a dual-purpose breed. Results show that selection for milk production only causes strong negative returns for secondary traits. Incorporating paternal half-sib or progeny information, obtained from progeny testing young bulls for milk production and secondary traits, improved the profit of the breeding scheme. Increasing the progeny group size improved returns from secondary traits. For a dairy breed, the model with paternal half-sib information resulted in a similar profit to a model with progeny information; genetic trend in the latter situation was higher. For the dual-purpose breed, a model with paternal half-sib information was superior to a model with progeny information due to reduced returns from beef production when the generation interval was lengthened. Selection for beef production traits was very effective in the MOET-nucleus breeding scheme. In particular, an increase in the number of eggs per donor cow improved the profit of the dual-purpose breeding scheme. The superiority of a MOET-nucleus breeding scheme for a dairy breed over an optimized progeny testing scheme was small when selection was also for secondary traits.