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. 

A DNA SNP profile analyses thousands of specific markers (SNPs) across an animal’s DNA to create a unique genetic fingerprint. This profile can be used to identify animals, verify parentage, and provide further genetic testing and genomic evaluations. A low-density profile provides a basic genetic fingerprint, while a higher density profile tests provides more markers for comprehensive genomic analysis and evaluations.

Coat dilution 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.  In Hereford cattle the gene causes dilution to black pigmentation leading to grey, smoky, or chocolate coat colours when carrier animals are crossed with black cattle (e.g. Friesian or Angus). Hereford cattle can carry the Dilutor mutation but will show no outward signs as they do not have any black pigment.

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.