The productive potential of a sheep is defined by its genetic makeup that interacts with environmental factors, such as nutrition, to determine the extent to which the potential is realised. While an animal's specific genetic makeup is unique to that animal, many important production traits are shared within breeds and bloodlines.
A trait is a production characteristic and can either be positive such as high growth rate or eye muscle depth, or negative such as poor conformation.
Some genetic traits are highly heritable and are readily passed across generations, while other traits are less heritable and, even though they are expressed by the sire or dam, may not be exhibited by the progeny.
Benefits of genetic improvement
Genetic improvement occurs when the average genetic merit for a particular trait is moved in a desired direction or towards the breeding objectives. One of the main ways to improve productivity is through genetic improvement.
Selecting the right genetics
When selecting, producers should focus on what they are trying to achieve in their breeding program. This should be expressed in clear breeding objectives that reflect the target market specifications. Australian Sheep Breeding Values (ASBVs) provide the only objective across flock genetic selection information for sheep producers.
Ongoing genetic improvement
Genetic improvement is cumulative and occurs across generations. The genetic improvement in a flock builds over time with ongoing genetic selection and management. Well considered breeding objectives are essential to maintaining and directing ongoing genetic improvement within a flock.
Gene marker research is identifying and examining genes that influence a range of traits important to production. In the future it is likely that there will be sets of markers available that can describe more complex traits such as parasite resistance and energy utilisation.