Submitted to: American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: August 21, 1999
Publication Date: N/A
Preliminary analysis of variance for quantitative trait loci affecting conformation traits using the grandaughter design and eight large US Holstein grandsire families revealed a strong association in two families between the predicted transmitting abilities for dairy form and marker genotypes for bovine chromosome 27 (BTA27). Results from Family 8 (79 sons) indicated an association (P = 0.000021) with a microsatellite marker located near the telomere of bovine chromosome 27 (BTA27). An association (P = 0.00001) was also detected in Family 2 (165 sons) with a microsatellite marker located approximately 20 cM from the centromere of BTA27. Interval analysis performed with additional BTA27 marker genotypes generated from Family 8 yielded a genome wide significant test score for dairy form QTL near the telomere of BTA27. Interval analysis of Family 2 is in progress. Genes found in the genomic fragments of conserved synteny between human chromosomes 4 and 8 and BTA27 are being used to develop additional informative markers to refine the QTL interval and identify potential candidate genes for dairy form. Even though the phenotypic scores for dairy form are based upon femininity, conditioning and dairyness; we hypothesize that this QTL is associated with fat metabolism. This hypothesis is supported by identification of similarly located QTL found in other cattle populations for marbling, milk fat yield, and milk fat percentage.