1. The maintenance of newly laid eggs in optimum condition till hatching is called incubation.
2. The fully developed chick emerges out of egg after an incubation period of 21 - 22 days.
3. There are two types of incubation namely natural incubation and artificial incubation.

They are classified based on the purpose for which it is farmed.
1. Egg layers - Eg: Leghorn
2. Broiler-type - Eg: White Plymouth rock
3. Dual purpose breed - Eg: Brahma
4. Game breed - Eg: Aseel
5. Ornamental breed - Eg: Silkie

Cattles are classified into three groups based on the purpose they serve to man.
1. Dairy breeds or Milch breeds: They are high milk yielders with extended lactation. Eg: Sindhi, Gir, Sahiwal, Jersey, Brown Swiss, Holstein cattle.
2. Draught purpose breeds: Bullocks are good for draught purpose. Eg: Kangayam, Malvi.
3. Dual Purpose breeds: Cows are meant for yielding more milk and bullocks are used for better drought purpose. Eg: Ongole, Hariana.

1. In fish culture, the fertilized eggs are removed from the spawning place and kept into hatching hapas.
2. Hatching hapas are rectangular trough-shaped tanks made up of mosquito net cloth supported by bamboo poles and fixed in the river.

Advantages of Aquaponic gardening:
1. Water conservation: No need of water discharge and recharge as the water is maintained by recycling process.
2. Pesticides: In this system use of pesticides is avoided and hence it is eco-friendly