Heritability of rectal temperature and relationships with growth in young cattle in a temperate climate

Abstract

Rectal temperature (RT) was measured over 4 years on 611 steers and heifers born in a crossbreeding trial in New Zealand. The cattle were the progeny of 28 sires representing four breeds. The first record was taken on each animal at about 15 months of age and a second record was taken on most animals about 2 months later. One crop of heifers was subsequently retained until 3 years of age and seven RT records per animal were collected in total. The repeatability and heritability estimates for RT averaged 0.20 and 0.19 respectively. A repeatability based on records obtained within a day was estimated as 0.44. The phenotypic and genetic correlations of RT with 15-month liveweight were -0.08 and -0.27 respectively; these were consistent in sign with data from tropical Australia, indicating that a lower RT was associated with greater weight for-age under temperate as well as tropical conditions.

Keywords:

• rectal temperature
• cattle
• bodyweight
• repeatability
• heritability
• correlation