BVD is a virus that is widespread in New Zealand cattle and causes reproductive losses, weak calves, reduced growth rates, lowered milk production and increased susceptibility to other diseases. BVD spreads through close contact with infected cattle. Persistently infected (PI) animals in the herd present the highest risk as they shed large amounts of virus throughout their lives. BVD can also be introduced through purchased, leased, borrowed or returning stock.

Poll/horn testing identifies whether an animal carries the genetic variant for polled (hornless), scurred (small, loose horn-like growths) or horned traits. The polled allele (P) is dominant to the horned allele (H) which means only animals that are homozygous recessive (HH) will be horned.  Animals that are homozygous dominant polled (PP) will only produce offspring that are polled; whereas animals that are heterozygous polled (PH) will appear polled (or scurred) but can produce horned offspring if mated to another heterozygous polled animal or a horned animal.

The MC1R gene, also known as the Extension locus, controls the production of black (eumelanin) and red (phaeomelanin) pigments. There are three alleles (forms) of this gene:

Dominant black (E^D) – this allele is dominant over both the other alleles so animals will have black coats if they have one E^D copy.

Neutral Wild type (E⁺) – varied colours, but reddish brown if animal is E⁺/e.

Recessive red (e) – all homozygous recessive animals will have red coats.

The coat dilutor is a mutation in the PMEL17 gene which causes a moderate or incomplete dilution of red and black pigmentation based on its interaction with the MC1R coat colour gene. Dilution is a dominant trait which means only one copy of the mutated gene will result in dilution, creating coat colours such as grey, dun, yellow, or light red. Two copies of the mutation (homozygous) causes a stronger dilution effect resulting in pale cream, silver dun, or pale yellow coats.

Myostatin (MSTN) is a hormone produced by muscle cells that inhibits muscle differentiation and growth. When the gene functions correctly, muscle growth is controlled, resulting in normal-sized animals. When mutations occur in the myostatin gene, muscle growth accelerates, leading to a condition called double muscling. While these mutations can enhance carcass traits, some variants are also associated with increased calving difficulty.

Tenderness is a complex trait influenced by muscle properties and the conditions that occur within the muscle after slaughter; it is a function of connective tissue, marbling or intramuscular fat, and postmortem protein degradation known as the calpain-calpastatin system.  Calpain316, Calpain4751, and Calpastatin alleles are associated with more tender meat.