The objective of the work presented herein was to identify and fine map quantitative trait loci (QTL) for birth weight, pre-weaning average daily gain, and average daily gain on feed in a commercial line of Bos taurus using the identical-by-descent haplotype sharing method. A sample set of male calves of the Beefbooster, Inc., M1 line were typed using 71, approximately evenly spaced, microsatellite markers on bovine chromosomes (BTA) 2, 6, 14, 19, 21 and 23. Thirty-four haplotypes were found to have significant associations with the three growth traits. The haplotypes spanned fifteen chromosomal regions, two on BTA2 (9.1--22.5cM, 95--100.3cM), three on BTA6 (8.2--50.1cM, 59.6--63.6cM, 83--86.2cM), three on BTA 14 (16.5--25.5cM, 27--50.8cM, 52--67.7cM), three on BTA 19 (4.8--15.9cM, 52--52.7cM, 65.1--65.7cM), two on BTA21 (9.9--20.4cM, 28.2--46.1cM) and two on BTA23 (23.9--36cM, 45.1--50.9cM). These QTL regions provide a reference for future positional candidate gene research and marker-assisted selection of growth traits. |