Breeding objectives
Meat & Livestock Australia July 24, 2020
Breeding program design
Your breeding objective should be well defined.
When developing your breeding objective ideally you should consider:
- Traits of importance
- Their desired level of performance
- Do they need to change or be maintained at their current level?
- The timeframe for change to occur.
Including traits in a breeding objective
Before any trait is included in a breeding objective, it should pass three basic ‘tests’. They are:
- Will the trait be economically important to you (and to your clients)?
- That is, will it have impact on your income and/or your costs, or those of your clients?
- Is the trait heritable and variable?
- Can it be measured, or scored, with reasonable accuracy and at an acceptable cost both directly or indirectly?
If the answer to all three questions is “yes”, then it is reasonable to include the trait in your breeding objective.
There are some traits for which the answer to question 1 is “yes”, but “no” for questions 2 or 3.
If the trait is not heritable or does not have any variation, then this is a trait that cannot be improved through genetic selection and other management options should be considered.
If the trait is too hard or expensive to measure, you might consider measuring an alternative trait (indicator trait), that is genetically related, easier and cheaper to measure than the original trait.
Selection criteria = characteristics that you measure
Breeding objective trait = characteristic you want to change/maintain
This approach is called indirect selection. An example of indirect selection might be to measure fat depth using ultrasound technology in live animals, in order to improve carcase leanness in slaughtered animals.