Genetic conditions are caused by an abnormality in an individual’s DNA.

The incidence of a single genetic condition is normally rare in a population, but the existence of genetic conditions is common:

  • Over 400 different genetic conditions have been identified in cattle.
  • All breeds can experience genetic conditions
  • Most genetic conditions do not have DNA tests available
  • Some examples of genetic conditions found in beef breeds include Arthrogryposis Multiplex (AM), Idiopathic Epilepsy (IE), Developmental Duplication (DD) and Factor XI Deficiency (F11).

Genetic conditions are often associated with:

  • Poor growth and fertility performance
  • Structural unsoundness
  • Varying levels of lethality
    • Some are semi-lethal (not all affected individuals survive to maturity)
    • Others are lethal (no affected individual survive to maturity)

The majority of genetic conditions seen in beef cattle are:

  •  Controlled by a single gene
  • Have a simple recessive inheritance and are expressed in progeny who receive a copy of the recessive allele from both their sire and their dam.
  • More likely to be expressed in populations with high levels of inbreeding.

Three possible genotypes:

  1. Free (zero copies of the genetic condition allele; does not have the genetic condition)
  2. Carrier (one copy of the genetic condition allele; does not have the genetic condition)
  3. Affected (two copies of the genetic condition allele; has the genetic condition)

Where available, DNA tests for genetic conditions can be used to manage and/or eliminate the genetic condition in a population.

The surest way to avoid the incidence of affected animals is to only use bulls that have been tested free of that genetic condition

  • When the genetic condition status of both parents is known, other strategies to manage the prevalence of carriers and incidence of affected animals are available

Optional reading: Further information can be found in this Managing Genetic Conditions article.