Development of the Canadian beef reference herd for gene mapping studies.

A project to map quantitative trait loci (QTL), in beef cattle using a full-sib design was initiated using six Bos taurus breeds. Embryo transfer was used in a large scale, short timeframe experiment to develop this herd for gene mapping. Full-sib families allowed for genetic information to be followed through both the sire and the dam and for both parents to be slaughtered so that carcass quality data could also be obtained from both of them at close to typical slaughter ages. Repeatability of response to superovulation was significant among the 3 flushes per female. Response to superovulation was negatively correlated with backfat of the donor. Crossbred embryos were found to have higher survival than purebred embryos.