Glossary of cattle genetics and marketplace terms

Terms used across WagyuSale, in sire summaries, and in the breeding and buying guides. Where definitions vary between breed associations, check your association's rules.

Accuracy — A measure of how reliable an EPD or EBV is. It rises as more performance, progeny and genomic data are added.

Affected — An animal with two copies of a recessive defect gene; it shows the condition.

AI (artificial insemination) — Placing semen into a female's reproductive tract with an insemination gun instead of natural mating.

AI certificate / semen certificate — A document from the semen owner that associations often require to register a calf sired by AI.

Allele — One version of a gene. Each animal carries two alleles for each gene, one from each parent.

Backcross / grading up — Repeatedly mating crossbred females to purebred bulls to raise the percentage of one breed in each generation.

Birth weight EPD/EBV — A prediction of calf birth weight relative to the breed base; important when breeding heifers.

Blastocyst — An embryo stage about a week after fertilization, the stage usually frozen or transferred.

Breed association / herd book — The organization that registers animals, records pedigrees and usually runs genetic evaluations for a breed.

Breeding value — The genetic merit an animal can pass on. See EBV and EPD.

Bull stud / collection centre — A facility that houses bulls and collects, processes and stores semen, often under official health supervision.

Calving ease — How easily calves are born. Calving-ease EPDs/EBVs help reduce difficult births.

Carcass weight — The weight of the dressed carcass after slaughter.

Carrier — An animal with one copy of a recessive defect gene. It is normal itself but can pass the gene on.

Clean-up bull — A bull turned out after AI or ET to mate females that did not conceive.

Conception rate — The percentage of inseminated females that become pregnant.

Conventional semen — Semen that has not been sex-sorted.

Crossbreeding — Mating animals of different breeds, often to gain hybrid vigour or combine strengths.

CSS (Certified Semen Services) — A program of the U.S. National Association of Animal Breeders that audits bull studs' semen health and quality standards; often a starting point for export.

Dam — The mother of an animal.

Direct transfer (DT) — A frozen embryo prepared so it can be thawed and transferred straight from the straw on farm.

DNA profile — A genetic fingerprint of an animal used for parent verification.

Donor — A female whose eggs or embryos are collected for embryo transfer or IVF.

Dry shipper — An insulated container that holds liquid nitrogen in an absorbent lining, used to ship frozen cattle and beef safely.

EBV (Estimated Breeding Value) — An estimate of an animal's own genetic merit for a trait, used by BREEDPLAN and others. EBV = 2 × EPD.

Embryo — A fertilized egg at an early stage of development.

Embryo transfer (ET) — Placing an embryo from a donor female into a recipient female who carries the pregnancy.

EPD (Expected Progeny Difference) — A prediction of how an animal's calves will differ from those of an average animal in the same breed evaluation.

Estrus (heat) — The short period when a female will accept mating; she stands to be mounted.

Export health certificate — An official veterinary certificate from the exporting country stating that a shipment meets the importing country's animal-health requirements.

Eye muscle area / ribeye area — The area of the main loin muscle, a measure of muscling and carcass yield.

F1 — The first-generation cross of two different breeds, e.g. a calf of a bull of one breed and a cow of another.

Fixed-time AI (FTAI) — Inseminating a group of synchronized females at a set time, without heat detection.

Flush — The procedure that collects embryos from a donor's uterus, usually about 7 days after insemination.

Free (tested) — DNA-tested and found not to carry a particular defect gene.

Free by pedigree — Not tested, but assumed free because both parents tested free.

Fullblood — In many breed registries, an animal of 100% breed descent with fully recorded ancestry; definitions vary by association.

Genomic EPD/EBV — A breeding value that includes DNA (genomic) information, giving higher accuracy in young animals.

Genotype — The genetic make-up of an animal for a gene or set of genes.

Heifer — A young female that has not yet had a calf.

Heterosis (hybrid vigour) — Extra performance of crossbred offspring compared with the average of their parent breeds, strongest in fertility and survival traits.

Heterozygous — Having two different alleles of a gene (for example, a carrier).

Homozygous — Having two identical alleles of a gene (for example, tested free or affected).

Import permit — A permit some countries require before animals or genetics can be imported.

In vivo embryo — An embryo fertilized inside the donor and flushed out, as opposed to made in the lab.

Index ($Index, selection index) — A single value combining several breeding values according to a stated breeding or market goal.

Intramuscular fat (IMF) — Fat within the muscle — marbling — measured by ultrasound or in the carcass.

IVF (in vitro fertilization) — Fertilizing collected eggs in a laboratory and growing the embryos before transfer or freezing.

Liquid nitrogen — The −196 °C liquid used to store frozen cattle and beef indefinitely.

Marbling — Flecks of fat within the muscle, strongly linked to eating quality and largely heritable.

Maternal traits — Traits of a cow as a mother: fertility, milk, calving ease as a dam, longevity.

OPU (ovum pick-up) — Collecting eggs directly from the ovaries with an ultrasound-guided needle, for IVF.

Parent verification — A DNA test confirming that an animal's recorded sire and dam are its real parents.

Pedigree — An animal's recorded ancestry.

Percentile rank — Where an animal's breeding value sits within its breed; top 10% means only 10% have a better value.

Polled — Naturally hornless.

Pregnancy rate — The percentage of females exposed to breeding (or receiving an embryo) that become pregnant.

Progeny — Offspring of an animal.

Proven sire — A bull with enough recorded calves that his breeding values have high accuracy.

Purebred — In many registries, an animal of a high, defined percentage of one breed (often after grading up); definitions vary by association.

Recessive — A gene that only shows its effect when two copies are present.

Recipient — The female that carries a transferred embryo to term.

Registration — Recording an animal in a breed association's herd book, giving it an official identity and pedigree.

Semen straw — A thin sealed plastic tube, typically 0.25 ml or 0.5 ml, containing one dose of frozen semen.

Sexed (sex-sorted) semen — Semen sorted so that most calves will be of one sex; usually more expensive with somewhat lower conception rates.

Sire — The father of an animal; also a bull used for breeding.

Sire summary — A published list of bulls with their breeding values, accuracies and percentiles.

Standing heat — The period when a female stands still to be mounted — the true sign of estrus.

Steer — A castrated male raised for beef.

Superovulation — Hormone treatment that causes a donor to release many eggs at once, for embryo flushing.

Synchronization — Using hormone treatments to bring a group of females into heat or ovulation at a planned time.

Tank-to-tank transfer — Moving straws from one owner's storage to another's, often within the same storage facility.

Terminal sire — A bull used to produce calves that will all be sold for beef rather than kept for breeding.

Unit (dose) — One straw of semen — normally one insemination.

Weaning weight — A calf's weight at weaning, adjusted to a standard age.

Yearling weight — An animal's weight at about one year of age, adjusted to a standard age.

Key takeaways

• Definitions of grades such as fullblood and purebred vary by breed association — always check the registry's own rules.
• When in doubt about a term in a listing, message the seller and ask.