Quantitative trait loci for fertility traits in Finnish Ayrshire cattle

v2008okBEL/EG

Quantitative trait loci for fertility traits in Finnish Ayrshire cattle

A whole genome scan was carried out to detect quantitative trait loci (QTL) for fertility traits in Finnish Ayrshire cattle. The mapping population consisted of 12 bulls and 493 sons. Estimated breeding values for days open, fertility treatments, maternal calf mortality and paternal non-return rate were used as phenotypic data. In a granddaughter design, 171 markers were typed on all 29 bovine autosomes. Associations between markers and traits were analysed by multiple marker regression. Multi-trait analyses were carried out with a variance component based approach for the chromosomes and trait combinations, which were observed significant in the regression method. Twenty-two chromosome-wise significant QTL were detected. Several of the detected QTL areas were overlapping with milk production QTL previously identified in the same population. Multi-trait QTL analyses were carried out to test if these effects were due to a pleiotropic QTL affecting fertility and milk yield traits or to linked QTL causing the effects. This distinction could only be made with confidence on BTA1 where a QTL affecting milk yield is linked to a pleiotropic QTL affecting days open and fertility treatments

Detection of quantitative trait loci for udder traits and stature in Finnish Ayrshire

vokBEL/EG

Utareen keskirepsahduksen geenikartoitus

vokBEL/EG

Mapping of a central ligament defect in Finnish Ayrshire dairy cattle

vokBEL/EG

Quantitative trait loci for udder conformation and other udder traits in Finnish Ayrshire cattle

Udder traits are important due to their correlation with clinical mastitis which causes major economic losses to the dairy farms. Chromosomal areas associated with udder conformation traits, milking speed and leakage could be used in breeding programs to improve both udder traits and mastitis resistance. Quantitative trait loci (QTL) mapping for udder traits was carried out on bovine chromosomes (BTA) 9, 11, 14, 18, 20, 23, and 29, where earlier studies have indicated QTL for mastitis. A granddaughter design with 12 Ayrshire sire families and 360 sons was used. The sires and sons were typed for 35 markers. The traits analysed were udder depth, fore udder attachment, central ligament, distance from udder to floor, body stature, fore teat length, udder balance, rear udder height, milking speed, and leakage. Associations between markers and traits were analysed with multiple marker regression. Five genome-wise significant QTL were detected: stature on BTA14 and 23, udder balance on BTA23, rear udder height on BTA11, and central ligament on BTA23. On BTA11 and 14 the suggested QTL positions for udder traits are at the same position as previously detected QTL for mastitis and somatic cell count.v2007okUtareen rakenteeseen ja käyttöominaisuuksiin vaikuttavia geenialueita suomalaisessa ayrshirepopulaatioss

Genome-wide scan for fertility traits in cattle using single-marker association and a genealogy based method

vo

Confirmation of quantitative trait loci for clinical mastitis in dairy cattle on chromosomes 2, 6, and 20

vo

Mapping of fertility traits in Finnish Ayrshire using high-density SNP data

vokBEL/EG

Mapping of fertility traits in the combined Nordic red dairy cattle population by genome-wide association

vo