Wednesday, August 12, 2015 - German researchers are reported to have discovered a new genetic defect in Holstein dairy cattle called Haplotype for Cholesterol Deficiency (HCD). A haplotype is a set of genetic determinants located on a single chromosome. If calves are homozygous for HCD, they have no cholesterol and live only a few months. The defective haplotype traces back to Maughlin Storm. Animals carrying the defect are difficult to track.
Paul VanRaden, a USDA research geneticist, notes that calf death caused by a genetic defect typically creates a greater economic loss than most other haplotypes that cause early embryo loss. Even though calf survival has low heritability, the dairy cattle geneticist recommends avoiding recessive defects by using sound selection and mating programs.
The Council On Dairy Cattle Breeding (CDCB) conducts genetic evaluations for economically important traits of dairy cattle. Their cooperator database is the largest in the world with approximately 70 million female phenotypic records and more than 300,000 males receiving genetic evaluations or genomic predictions.
For more specifics on HCD, refer to the technical note here