Detection of Quantitative Trait Loci Affecting Leg Conformation Traits in Danish Holstein Cattle

Strong legs and feet give longer herd life of dairy cows. Therefore, many countries include measures of leg and feet conformation traits in their breeding programs, often as early predictors of longevity. Five leg conformation traits were measured on grand-daughters of 19 Danish Holstein sire families with 33 to 105 sons. The traits measured were: rear legs side view, rear legs rear view, hock quality, bone quality and foot angle. A genome scan was performed to detect quantitative trait loci (QTL) based on the 29 autosomes using microsatellite markers. Data were analysed across and within families for QTL effecting leg conformation traits. A regression method and variance component method was used for QTL detection. For the five different leg conformation traits seven chromosome wise significant QTL were detected across families for rear legs side view, 4 for rear legs rear view, 5 for hock quality, 4 for bone quality and one for foot angle.