- well defined
- reliable, easy and cheap to measure and record
- aim to the future (help the animals adapt to the coming changes.
Once a list of breeding goals has been made, the goals need to be weighed. Every goal cannot be the most important. Factors influencing the weighing process are
- defining efficiency: biological and economical views
- target of selection: maximizing profit or minimizing costs
- production system: developing animals / herds / breeds
- limiting factors: Limiting production inputs, number of animals
- range of planning: what needs to be inmproved first, and what later
- different roles in the food production chain: slaughterhouses have different goals than piggeries or animal welfare professionals
|Example: values of fertility and udder health|
Costs of traits for pigs have been valued to show how much an improvement of one unit of standard deviantion increases the price of pig meat. In one study, the most profitable trait was the size of litterm which increased the price of pig meat 2 cents / kg. The least profitable traits was the size of the first litter. Some breeding programmes like the Northern European NAV has defined clear values for different traits, as can be seen in the picture below.
|Values of traits in NAV. (c) http://www.nordicebv.info|