If you find
It can be difficult to “let go” of animals you have raised
Sentiment can interfere when culling, making it hard to make the best decisions at the drafting race
It takes time and effort to track all genetically-relevant animals
Then,
To cull the right animals or plants you need to know what to cull. This means you need to know which you want and which you don’t.
For this you need to know what you want and why and you need to measure it and to relate it back to each individual.
As an example, if you want to reduce internal parasite problems in ruminants, you need to manage a generation of animals so that they are raised under near-ideal conditions and certainly under even conditions so that you get a relatively even expression of their genetic potential for resistance to internal parasites.
Then each animal’s resistance needs to be measured.
All animals that are poorly resistant are likely culls. If these animals remain in the mob too long, they will contaminate the pasture at a high level. This will affect the clear and even assessment of the next generation. So they need to be removed from the main mob and kept separate until they can be culled.
The ones that need to go can be culled when circumstances are right, such as after shearing so you have made whatever profit you can from them.
This pattern depends on seedstock evenly assessed and Seedstock linked to relevant relatives.
Why they need to go:
- Parasite carriers and infection carriers contaminate the environment and cause others to get infected.
- If you let them breed, they also contaminate the gene pool with that tendency.
- So it is best to separate them if they are causing others to be infected and it is best to eliminate them from the breeding stock if they may be contaminating the gene pool.
Having a Top mob allows the ones that are part of your future to stay and be bred from and thus pass their genes down.