Livestock Breeding Objectives
Purchasing rams and bulls is a significant cost for graziers, with the decisions made having significant ramifications for the flock or herd for many generations. Understanding the traits which are most important to their production system, expressed in a clearly defined breeding objective, allows breeders to buy specific sires which will achieve their goals in the medium to long term.
Every grower will have a different set of objectives, which will depend on their situation and production system. The following steps are key to formulating individual breeding objectives:
Identification of traits of economic importance to the enterprise.
Traits selected, need to be ranked with relative importance to each other. This ranking will determine the selection pressure of each trait, when selecting new rams/bulls and the inevitable compromises that need to be made.
Targets for the medium and long term need to be set for every trait selected. These targets need to be objective and realistic, as they should be revisited each year to determine the progress of change.
Comparison of the flock/herd and the ram/bull team to the industry average for each trait. This is best done with Australian Sheep Breeding Values (ASBVs) and Estimated Breeding Values (EBVs), which will identify the traits where the most gain can be made.
The chosen breeding objective and the targets should be similar to those of the stud from which sires are sourced. However, where a stud produces a large number of rams or bulls, it may be possible to select individual animals which meet one’s criteria, even if the stud’s breeding objective differs slightly from this. If this is not the case, it may be necessary to look at alternative studs.
Breeding objectives should not only be used when purchasing sires; they are also fundamental when classing replacement females. The traits selected should be the main basis for culling females, in addition to assessing structural faults which lead to removal from the herd/flock.
A breeding objective selected should be based predominately on income generating traits. However, other factors which can improve operating or production efficiency, animal welfare, reduce labour requirements, or increase the ease of management of the flock/herd, should also be considered.
Examples of some of these traits include worm resistance, wrinkle score, poll status and fat score.
Further information can be found at the following link:
https://www.mla.com.au/research-and-development/Genetics-and-breeding/breeding-objectives-and-selection/#