Heritability estimates of calving date in Nellore cattle

Abstract Text: The objective of the study was to estimate the heritability of Calving Date (CDate) in Nellore cattle and the possibility of its use as a reproductive trait in a breeding program. A dataset of 148,897 births of Nellore females calved between 1992 and 2011 were used. The data was provided by the Nellore Breeding Program Qualitas. The CDate trait was calculated asthe day number in which the cow calved within the calving season. The variance components were estimated through the restricted maximum likelihood using the software AIREMLF90. The heritability estimates found for CDate without penalty was 0.26 while estimates for CDate with penalty (21 days added highest day number if the female was open) was 0.09. Our findings suggest the inclusion of CDate trait additive genetic value as a selection criteria in beef cattle breeding programs.

Keywords: beef cattle, genetics parameters, reproduction trait