FINGERLINGS FEED PRODUCTION

Cultural practices used for foodfish production differ from farm to farm, and the process of growing a food-sized catfish can take many paths after the fingerling phase. Most farmers divide fish stocks only once between the nursery
phase and the foodfish growout
phase. In this scheme, fingerlings
are harvested and restocked into
foodfish ponds at roughly one-
tenth to one-twentieth the density of nursery ponds because fish will be ten to twenty times heavier when harvested as foodfish. This one-step production scheme is not as simple as it appears because there are many options for managing foodfish ponds. Another approach to producing food-sized fish is to divide twice between the nursery phase and foodfish growout. The first division produces a medium-sized fish called a "stocker". The second division is made when stockers are harvested and restocked for growout to food size. In this scheme, small fingerlings (2 to 3 inches) are stocked at about 40,000
to 60,000 fish/acre and grown over one season to produce stockers weighing 0.1 to over 0.3 pounds. The stockers are then harvested and moved to foodfish growout ponds. As with the one-step scheme described above, there are several options for foodfish growout using stocker-sized fish. The three fundamental production variables in foodfish growout are cropping system, stocking rate, and size of fingerlings to stock.
Farmers use various combinations
of these variables and it is impossible to describe a typical
management scheme for
production of food-sized channel
catfish. Farmers have developed
and used various production
schemes based on experience, personal preference, and perceived productivity and profitability. Cropping system refers to the stocking-harvest-restocking schedule. In the single-batch system, the goal is to have only one year-class of fish in the pond at a given time. Fingerlings are stocked, grown to the desired
harvest size, and all fish are
harvested before the pond is
restocked with new fingerlings to
initiate the next cropping cycle. In
the multiple-batch system, several different year-classes of fish are
present after the first year of
production. Initially, a single
cohort of fingerlings is stocked. The
faster-growing individuals are
selectively harvested ("topped") using a large-mesh seine, followed
by addition ("under- stocking") of
fingerlings to replace the fish that
are removed plus any losses
incurred during growout. The
process of selective harvest and understocking continues for years
without draining the pond. Whether ponds are operated as
single-batch systems or multiple-
batch systems, stocking rate is best
defined as the maximum fish
density (number per acre) over the
production period. Under commercial conditions, stocking
rate becomes an approximate goal
rather than a precisely managed
population variable because it is
nearly impossible to know the true
inventory of fish in large commercial ponds that are used for
several years without draining.
There is no consensus on the best
stocking rate for commercial
production and rates used in the
industry range from less than 500 fish/acre to more than 10,000 fish/
acre. One explanation for the wide
range of stocking rates used by
catfish farmers is that production
goals, facilities, and resources vary
from farm to farm. The size of fingerling to stock is a
critical factor in foodfish
production, but very little
systematic research has been
conducted to determine the
relationship between fingerling size at stocking and economic
returns. Large fingerlings will reach
foodfish size faster than small
fingerlings, but large fingerlings
are expensive because they require
more time and space to produce. In addition, large fingerlings can be
difficult to obtain because most
fingerling producers prefer to stock
fry at relatively high densities and
move fingerlings to foodfish ponds
as soon as possible to avoid risk of loss to infectious diseases and
predacious birds. The best size
fingerling to stock is therefore a
compromise that depends on
cropping system, fish stocking
density, and fingerling availability.
FOR CONSULTANCY CALL 08032861326.

Share this: