Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 1999
Publication Date: N/A
Technical Abstract: A quantitative trait loci for birth and growth traits has been previously identified on chromosome 6 in Bos indicus x Bos taurus crosses. As part of a study focused on identifying quantitative trait loci (QTL) for economically important traits, a region on this chromosome was scanned. A half-sib family (n = 246), from a Belgian Blue x MARC III sire, was used. Seven microsatellite markers (INRA133, BM1329, BMS2508, BMS382, BM3026, BMS483 and BM415), spanning 76 centimorgans, were used to evaluate this region. Mean birth and yearling weights were 42.9 +/- .4 kg and 406 +/- 2 kg, respectively. Statistical evidence (nominal P < .00005; expected number of false positives = .05) supports a QTL in this region for both traits. The maximum F-statistic for birth weight is located at 36 cM, and for yearling weight at 43 cM, from the most centromeric marker of the linkage group (INRA133). The difference between alternative alleles inherited from the sire at the maximum F-statistic was -3.24 +/- .7 kg and -8.8 +/- 2 kg for birth and yearling weights, respectively. Individuals inheriting the MARC III allele from the sire were heavier compared to those inheriting the Belgian Blue allele. This QTL segregates independently from the gene that causes double muscling in cattle without evidence of epistasis between both loci.