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 follo wed through both the sire and the dam and for both parents to be slaughtere d so that carcass quality data could also be obtained from both of them at close to typical slaughter ages. Repeatability of response to superovulatio n was significant among the 3 flushes per female. Response to superovulatio n was negatively correlated with backfat of the donor. Crossbred embryos we re found to have higher survival than purebred embryos. (C) 2001 by Elsevie r Science Inc.