Dexter

This DNA-based parentage test uses microsatellite marker analysis to compare the DNA profile of an offspring to the profiles of possible parents. The markers reported include the 12 ISAG-recommended markers for cattle. Genotypes follow the international nomenclature standard for cattle.

Beta-lactoglobulin is the major whey protein gene. Two common variants, A and B, are associated with different concentrations of beta-lactoglobulin protein in cow's milk.

Kappa-casein is an important gene for protein yield and percentage in milk. Two common variants, A and B, are associated with different concentrations of kappa-casein protein in cow's milk.

Genetic variants of beta-casein, a protein of cow's milk, can be classified into two groups, A1 and A2, based on the specific amino acid in position 67 of the protein. This A1 and/or A2 group designation may be of interest to breeders developing herds for human health benefits.

The Melanocortin 1 Receptor (MC1R) gene (also called Extension) controls the production of black and red pigments in the coats of domestic cattle, creating base colors that may then be further modified by other genes.

The dun coloration in Dexter cattle is caused by the dilution of black pigment in the hair, producing shades of dark brown to gold. This color dilution is caused by a recessive mutation.

Bulldog dwarfism is a lethal genetic defect of Dexter cattle. Affected fetuses have severe disproportionate dwarfism, a short vertebral column, a large head, and are naturally aborted around seven months of gestation. The two known mutations are specific to Dexter cattle and may be present in Dexter crossbreds.

Pulmonary hypoplasia with anasarca (PHA) is a lethal genetic defect characterized by incomplete development of the lungs and severe subcutaneous fluid accumulation, leading to abortion or the birth of a dead calf.

A freemartin is a female that is born as a twin with a male and is sterile as a result of exposure to masculinizing hormones produced by the male in utero.