Genetic parameters for average daily gain, area of m. longissimus dorsi, feed efficiency and feed intake capacity in young bulls of dairy populations

Records from three Danish performance test stations for beef production on 7641 bull calves of three Danish cattle populations tested in the period from 1984 to 1994 were used to estimate genetic and phenotypic parameters for average daily gain (ADG), area of rn. longissimus dorsi (LD), feed efficiency (FE) and feed intake capacity (FIC). The three populations were Red Danish (RD), Danish Black and White (DBW) and Danish Jerseys (DJ). Across-population heritability estimates of 0.43, 0.37 and 0.25 were obtained for ADG, FE and FIC, respectively. Estimates for the individual populations were similar for ADG and FIC, but for FE estimates mere 0.45, 0.33 and 0.24 for RD, DBW and DJ, respectively. Across-population estimates of genetic correlations were 0.53, 0.00 and - 0.77 for ADG-FE, ADG-FIC and FE-FIC, respectively, with minor deviations in estimates for individual populations. Selection for FIC in young bulls will have an undesirable effect on beef production efficiency in young bulls. LD area was only measured on the dual-purpose populations RD and DBW. Differences in genetic correlations between the above-mentioned traits were slight between the two populations. LD area was not correlated with ADG, FE or FIC, which indicates good possibilities for simultaneous genetic improvement in growth traits and carcass traits.