Recessive Genetic Conditions
The Angus Society has identified a range of recessive genes which occur in the breed. These have a very small probability of occurrence. There are genetic tests for these conditions and software calculations as to the probability of untested animals carrying these genes.
When a male and female are mated both must carry the recessive gene for it to be passed on to their calves. With such a mating there is a 25% chance that the calf will be normal, a 50% chance that it will be a carrier with one copy of the defective gene, and a 25% chance that it will inherit two copies of the defective gene, in which case they may be still-born or their development adversely affected.
We DNA test our bulls for the recessive genes Arthrogryposis Multiplex (AM), Neuropathic Hydrocephalus (NH), Contractural Arachnodactyly (CA) and Developmental Duplications (DD). We only buy bulls that have been shown not to carry recessive genetic conditions. Therefore in our herd, as in most stud herds, the adverse recessive genes are progressively being eliminated.
The greatest risk to commercial breeders is buying an unregistered bull with unknown genetic background that may be a carrier.
