animal production - CSK Himachal Pradesh Agricultural University ...

(i) Liming: Liming of the pond is necessary to eradicate the harmful insects, micro-organisms, to render soil alkaline
and provide calcium to the growing fish. If soil is not acidic, the lime can be used at the rate of 25 g per sq m and if soil is
acidic, increase the quantity of lime by 50%. After broadcasting of lime in whole tank, it must be left dry for 4 days to one
week.
(ii) Manuring: Manuring is done with the objective to increase the plankton which form the natural food of the fish.
The rate of manure depends on the fertility status of soil. The organic manure such as cow dung is used @ 20 tonnes/ha
i.e. 2 kg per sq m area in Palampur valley. Initial manuring is to be done with 50% of total required manure and
subsequently the rest 50% should be used in the equal monthly installments. Fill the tank with water just after manuring and
leave it for 12-15 days.
(iii) Control of aquatic weeds and predators: The algal blooms are sudden out-bursts due to higher manuring or
organic effluent. These blooms liberate good amount of carbon dioxide leading to oxygen depletion which can cause large
scale mortality. If reddish scum appears on the surface of the water, this means the outbreak of algal bloom. The manuring
and artificial feeding should be stopped immediately and allow fresh water in the pond. If the algal blooms are in excess,
spray 3% copper sulphate solution selectively to worst affected areas of pond or superphosphate at the rate of 1 g/m water
area. The eradication of weed and predatory fishes is necessary to avoid competition with culturable fishes for space and
food. These fishes may be eradicated either by repeated netting or draining the water or poisoning the pond. Generally
used poisons for this purpose are mahua oilcake (200 ppm), 1% tea seedcake or turpentine oil @ 250 1/ha. The other
chemicals such as Aldrin (0.2 ppm) and Endrin (0.01 ppm) can also be used. In case of the use of these chemicals, the
stocking of fish seed (fry/fingerlings ) may be delayed atleast by 10 to 25 days so as to facilitate elimination of the chemicals/residues.
Stocking
Judicious selection of compatible fast growing species is of vital importance in maximizing fish production. A
combination of three species viz. mirror carp, grass carp and silver carp fulfills the species selection requirements and this
model has proven to be the ideal combination for sub-temperate region of the State. Of these, mirror carp is a bottom
feeder, grass carp is a macro-vegetation feeder and silver carp is surface feeder.
Species ratio
Selection of species ratio generally depends upon the local conditions, seed availability, nutrient status of pond,
etc. The species ratio in the recommended model for Zone II is - 3 mirror carp : 2 grass carp : 1 silver carp.
Stocking details
Rate of stocking usually depends on the fertility of the pond and the measures adopted to increase its biological
productivity by manuring, artificial feeding, monitoring of growth and maintaining good health of fish. The rate of stocking
recommended for this zone is 15,000 fingerlings per ha with artificial feeding.It is good to stock the ponds with fingerlings of
40-60 mm size for better survival and high production. It is better to stock the pond after 15 days of manuring in early hours
of day or in the evening. The cloudy day or warmer part of day is to be avoided for stocking.
Supplementary feeding
The level of natural food organisms in the fish culture ponds can not be maintained to the required extent even
after manuring. Hence, supple-mentary feeding with diet rich in protein,carbohydrates and fats is essential for higher rate of
fish growth. The ingredients generally used for artificial feeding are groundnut oil cake and wheat bran in the ratio of 1:1.
Feed should be preferably provided in the form of pellets or bowls @ 2% of the total biomass and feed them by hand at
different places in the ponds so that all the fishes must get uniform quantity of feed for their uniform growth.
Grass carps are to be fed with chopped succulent grass or discarded vegetable leaves. Kitchen refuse can also be
used as supplementary feed for fish culture.
A practical feed formula which is in practice at Fish Farm,CSKHPKV is given below:
Ingredients Ingredients Qty for preparing
(%) 10 kg feed
37