5.11- Breeding animals

Understand that animals with desired characteristics can be developed by selective breeding.

Example: Cow
Desired: Milk yield

• The earliest farmers noticed that some cows make around 50ml of milk each time they are milk and a few others make 150ml of milk but most of them make 100ml. 
• The farmer will take all the milk but choose to breed only the ones that make 150ml milk
• In the next generation a few cows produce 100ml, 200ml and the majority produce 150ml.
• Of course the farmer take all the milk and select the cows that produce the most milk for breeding
• Perhaps in the next generation the cows will produce 150 to 250 ml of milk.
• The farmers are therefore developing the desired characteristics by selective breeding.
• For this to work the milk yield must be genetic