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Preliminary Investigation into Genetic Parameters for Feedlot Traits of Angus Cattle in South Africa
Selection to improve feed efficiency in beef production is aimed at reducing feed cost. However, breeding animals also contribute to feed cost, not only feedlot animals. Selection for residual feed intake (RFI) differs from other feed efficiency traits since it is independent from growth and body weight, thus not leading to increased maintenance requirements in mature animals. Performance data from young South African Angus bulls tested at centralized growth test stations were used to calculate genetic parameters for seven post weaning growth- and feed efficiency traits. Data collected from 1979 to 2009 of performance tested bulls were used in the analysis. Difficulties were experienced determining correlations for residual traits and FCR (feed conversion rate), this supports MacNiel et al. (2013) argument that it is more beneficial to base selection on the component traits used to determine ratio and feed efficiency traits.
Keywords:
residual feed intake
residual daily gain
