5.11 Breeding Animals

Example of Breeding animals : cows


 The desired outcome for the cow is the milk yield.

1.  The earliest farmers would realise a few cows would be producing 50 ml of milk, while some produces 150 ml of milk - roughly  most of the cows would be producing 100 ml of milk.
2. The farmer will then collect all the milk and he will only choose cows which produce 150 ml milk as the breeding cows. 
3. In the next generation we find that a few cows are producing 100 ml, a few cows are producing 200 ml and the majority of cows will be producing 150 ml of milk.

He will then repeat the same method selecting the cows which produce 200 ml milk as the breeding cow. And in the next generation there would be a few cows producing 150 ml of milk, a few producing 250 ml of milk and the majority producing 200 ml of milk.

So as we progressively select, we change the desired characteristic. We are able to develop the desired characteristic by selective breeding.