Advances in using nationally recorded data to address breeding objectives in beef cattle breeding

摘要

The paper deals with the reasons and need for the setting breeding goals based on biological efficiency and local production systems, while using available recordings in an national database. Two such traits, of major economic importance for the SouthAfrican beef industry is briefly discussed. The first trait deals with profit of beef cattle, intensively fed, in feedlots. A marked difference exists among animals for their profitability in feedlots and the selection on the components, in the past, has resulted in a positive trend for the Bonsmara breed in feedlot profit. A new definition of reproduction efficiency (or success) is suggested. It is based on the number of calves of females by the age of six years. The heritability estimate for the trait is 0.11 ±0.01 and the EBV variation among bulls shows marked differences in income from their progeny.