Poultry and fish production

Poultry: eggs and meat

Poultry are the birds that we keep for food, such as hens. Hens are kept for two uses.

• Layers are hens that are kept for eggs.
• Broilers are hens that are kept for meat.

Indian breeds, such as Aseel, are hardy but give fewer eggs. Foreign breeds, such as Leghorn, give more eggs. Farmers cross the Indian and the foreign breeds to get better poultry. The farmer looks for these traits:

• a large number of good chicks;
• dwarf broilers, as parents of the chicks that are raised for meat;
• the ability to stand the heat of summer;
• a low need for care and money;
• smaller egg-laying birds, which eat less feed.

Looking after poultry

Poultry need good housing, good feed and protection from disease.

• Housing. The sheds must be clean and dry, with the right temperature. A crowded or dirty shed spreads disease.
• Feed. Layers and broilers need different feed. The feed of broilers is rich in protein and has enough fat for fast growth. It also has a good amount of vitamins A and K.
• Disease. Bacteria, viruses, fungi and parasites can make birds ill. A vaccination programme protects the flock, and the farmer keeps the shed clean.

Move the sliders. With the starting values, $70$ out of every $100$ hens lay, so a flock of $400$ gives $280$ eggs in a day.

Fish production

Fish are a rich source of protein. We get fish in two ways: by capture, which means catching wild fish, and by culture, which means rearing them.

• Marine fisheries use the sea. Fishermen catch fish from boats with nets. Echo-sounders and satellites help them find shoals, which are large groups of fish. Pomfret, mackerel, tuna, sardines and Bombay duck are marine fish.
• Mariculture is the rearing of marine animals and plants in sea water. Mullets, bhetki and pearl spots are farmed, and so are prawns, mussels, oysters and seaweed.
• Inland fisheries use fresh water in ponds, canals, lakes and rivers, and brackish water in places where a river meets the sea. Fish culture in ponds is also called aquaculture.

Composite fish culture

In composite fish culture, five or six kinds of fish are reared in the same pond. This works because each kind feeds at a different level.

• Catla feeds near the surface.
• Rohu feeds in the middle of the water.
• Mrigal and common carp feed at the bottom.
• Grass carp feeds on the weeds.

They do not compete for food, so the pond gives a larger harvest than it would with one kind of fish.

Where the young fish come from

Many fish do not breed in ponds. Farmers once collected young fish, called seed, from rivers. That seed was mixed with other kinds of fish, and there was never enough of it. Today hatcheries give the farmer pure seed of the chosen kinds. In a hatchery, hormones make the fish breed.

Try it in Python

The program finds the eggs and the income of a layer flock in a week.

You should see $280$ eggs a day, $1960$ eggs a week and $11760$ rupees.

Practise with new numbers

Common mistakes

• Mixing up layers and broilers. Layers are kept for eggs. Broilers are kept for meat.
• Thinking every hen lays every day. Only a share of the flock lays on a given day.
• Thinking composite culture means one kind of fish in each pond. It means several kinds together in one pond.
• Thinking mariculture uses fresh water. Mariculture uses sea water.
• Forgetting that fish die before the harvest. The fish caught are fewer than the fingerlings put in.

Remember these

• Layers give eggs. Broilers give meat. Indian and foreign breeds are crossed.
• Poultry need clean housing, the right feed and vaccination.
• Fish come from capture and from culture, in the sea and in fresh water.
• Composite fish culture: catla at the top, rohu in the middle, mrigal and common carp at the bottom, grass carp on the weeds.
• Hatcheries give pure fish seed, using hormones to make fish breed.

Check yourself

Try each one on your own first. If you are stuck, open a hint. Then check with Show the answer.

1. Which hens are called layers, and which are called broilers?

2. Why do farmers cross Indian breeds of hens with foreign breeds?

3. What is the difference between capture and culture of fish?

4. Why can five kinds of fish live together in one pond and give a good harvest?

5. A flock of $300$ hens has $60$ out of every $100$ laying. How many eggs are laid in a day?