Write notes on −
(a) Crossbred animals
(b) Sheep rearing
(c) Pisciculture
(d) Cultured pearls
(a) Crossbred animals are the animals obtained from the mating of two distinctly different breeds of animals. Crossbreeding is an effective tool that can be used to obtain a strong animal with desirable traits of both the parent animals. The yield and profits from such animals are greater. For example, on an average, a common Indian cow produces 5−6 litres of milk. But, if it is crossbred with the Jersey or the Red Dean bull, the hybrid variety yields 10−12 litres of milk. Some common breeds of cow selected for crossbreeding at national level include Kandhari, Devani, Khilari and Dangi cow varieties of Maharashtra.
(b) Sheep rearing is primarily concerned with the rearing of lambs or sheep for meat or wool. Sheep rearing is done in dry lands with low rainfall. The sheep are easy to rear by any farmer as it does not incur any expenditure to feed them. Sheep feed on wild plants such as the bor, babhul trees, shrubs etc. and also on the wastes of wheat, rice, jowar or groundnut crops. Sheep not only provide us with wool, meat, skin but the droppings of sheep are rich source of nitrogen, phosphorous and potash that can be used by farmers as manure in their crop fields. Hence, it is profitable for the farmer to keep sheep.
(c) Pisciculture is the production and management of fish. The fish obtained from fisheries are larger as they receive proper food, and grow in a healthy environment. Thus, they are commercially useful. Earlier man used to catch fish that were available in nature but now desired varieties of fish are grown from their ‘seeds’ that have been made available by the government. Fish is an important source of dietary proteins. Besides proteins, fish is also rich in vitamins A, D and E.
Examples of freshwater fish - catla, rohu, mrugal and carp
Examples of marine fish - boi (mulletfish), muddushi (shellfish), renavi and khasi
(d) Pearls are obtained naturally from the marine animal called oyster. In order to produce the large pearls, an artificial technique has been developed in which a grain of sand is inserted in the oyster's body at the right time. Such large pearls obtained on a commercial scale are referred to as cultured pearls.