Feeding
Soon after stocking, the fish start grazing natural food available in the pond irrespective
of their stage of life cycle. Spawn feeds voraciously on plankton. Therefore, immediate
steps must be taken for providing supplementary feed. In the case of nursery ponds
where spawn are reared for about a fortnight up to fry stage, supplementary feed
is broadcast on the pond surface in the form of fine powder daily in the morning
hours at prescribed rates.
Rates of daily supplementary feeding at various
stages of culture
Stage
|
Daily feeding rate
|
Spawn to fry
|
4–8 times of the initial body weight
|
Fry to fingerlings
|
50–100% of the initial body weight
|
Growers
|
1 – 2%
|
Brood fish
|
1 – 3%
|
(Source: FAO)
Feeding schedule for nursery ponds
Period (Day from the date of stocking)
|
Rate of feeding
|
Amount of feed for 0.1 million of spawn
|
1 – 5
|
4 times the total initial weight
|
560 g/day
|
6 – 12
|
8 times the total initial weight
|
1120 g/day
|
13
|
No feed
|
-
|
14
|
Harvesting
|
|
(Source: FAO)
Supplementary feeding
Fishes need much more food than what is available naturally in the pond. Fishes
can be fed with a mixture of bran and oilcake in equal quantities daily. The feed
should be placed on a bamboo tray and lowered to the pond bottom or it can be sprayed
at the corners. After some time the fishes will get used to this type of feeding
and aggregate at the same place at particular time.
Recommended supplementary feeding rate
Culture period
|
kg per day
|
I quarter
|
1.5 to 3
|
II quarter
|
3 to 6
|
III quarter
|
6 to 9
|
IV quarter
|
9 to 12
|
(Source: CIFA)
Fertilization
Periodic fertilization, which ensures replenishment of nutrients and consolidation
of the energy base for microbial decomposition activities. Lime should be applied
first followed by the organic manure and finally the inorganic fertilizers. These
fertilizers should be applied only when the physical conditions of the water are
most suitable such as plenty of sunlight, adequate oxygen, optimum temperature,
adequate water level and low wind velocity. Turbid water with a high content of
suspended solids are not preferred. Fertilizer should be sprayed or distributed
properly over the water surface during the daytime when the top layer of water is
warmer and lighter.
Inorganic fertilization may be done at monthly intervals alternating with organic
manuring. However, the monthly rate of fertilization will depend on pond productivity
and the growth of the fishes. It should be ensured that excess fertilization does
not take place, which may result in eutrophication.
Periodicity of fertilization in nursery, rearing
and stocking ponds
Ponds
|
Manure
|
Periodicity
|
Nursery ponds
|
Organic manure
|
3 weeks
|
Rearing ponds
|
Organic manure and Inorganic fertilizer
|
3 weeks - daily
|
Stocking ponds
|
Organic manure and Inorganic fertilizer
|
Monthly
|
|