Growth
of stocker channel catfish to large market size in single-batch culture
B.W.
Green, C.R. Engle-2004
Journal
of the World Aquaculture Society, 35(1): 25-32
(from ISI Current Contents)
Abstract:
Catfish farmers increasingly are producing fish larger than the traditional
size of 0.45-0.57 kg/fish in order to meet processing plant requirements for
larger fish. Production of larger channel catfish Ictalurus punctatus in
multiple-batch culture has been investigated in a few studies, but the
impact of understocked fingerlings on growth of carry-over fish is unknown.
The present study was conducted to quantify growth, feed conversion ratio,
net daily yield, and net and total yield of stocker channel catfish grown in
single-batch, one-season culture to mean individual weights of 0.60, 0.72,
0.91, or 1.17 kg/fish. Channel catfish (mean weight = 0.26 kg/fish) were
stocked into 12 0.1-ha ponds at 11,115 fish/ha. Fish were fed a 32% crude
protein floating extruded feed once daily to apparent satiation. When the
average weight of the fish population reached the target weight, three
randomly selected ponds were harvested. Fish growth was linear in all
treatments. Growth rates were similar for fish grown to 0.60, 0.72, and 0.91
kg/fish, and significantly lower (P < 0.05) than for fish grown to 1.17
kg. Variation in individual fish weight increased linearly with increased
duration of culture period. Feed conversion ratio averaged 1.9 and did not
differ significantly among treatments. The percentage of the fish population
at harvest that fell within the 0.57 to 2.04 kg-size range preferred by
processing plants increased from 56.6 to 98.5% as the mean weight at harvest
increased from 0.60 to 1.17 kg/fish.
(Univ.Arkansas,
USDA ARS Aquaculture Syst. Res. Unit Aquaculture Fisheries Ctr. Excellence,
1200 N Univ. Dr., MS 4912, Pine Bluff AR 71601 USA)