QTL Detection for Fat Yield on BTA14 Using Linkage Disequilibrium Based Methods

Abstract Text: In this study five models were used to identify quantitative trait loci (QTL) for fat yield in bovine chromosome 14 (BTA14): (1) a linear mixed model that includes covariance among all individuals, (2) the same linear mixed model with a probability that one individual belongs to one previously detected subpopulation as covariable, (3) the same mixed model association using the approach of principal component analysis, (4) a regression model (LD decay), and (5) a regression linkage disequilibrium linkage analysis (LDLA). The mapping population consisted of 23 paternal half-sib families with 870 offspring (77% Holstein purebreeds and 23% Jersey x Holstein crossbreds). All models detected a chromosomal region falling within the region that encompasses the postulated DGAT1 gene. In addition, both LD decay and LDLA identify two additional regions (25 Mbp and 80 Mbp) that could be associated to fat yield.

Keywords:

dairy cattle

linkage disequilibrium

QTL