Evaluation of decapsulated
Artemia cysts in hatchery diets for channel catfish Ictalurus punctatus fry
and effects on subsequent fingerling production
C.R. Weirich, R.C. Reigh, D.W. Glenn-2000
Journal of the World Aquaculture Society, 31 (4) :
609-617 (from Current Contents)
Abstract:
Two 10-d hatchery growth trials were conducted to
determine if differences in growth, body composition, and survival existed
among catfish fry Ictalurus punctatus fed a diet of 100% catfish-starter
(CS) or CS in combination with decapsulated Artemia cysts (DAC) at 25%, 50%,
or 75% of diet weight. A 120-d production trial was undertaken immediately
following the first hatchery trial to evaluate the effects of diet on
production characteristics (survival, length, weight, feed conversion ratio,
and total yield) of fingerling catfish produced from hatchery-raised fry.
Fry fed diets containing DAC weighed 61-98% more (P < 0.05) than fry fed
only CS. The size differential of DAC-fed fry was maintained through 120 d
of growth in simulated nursery ponds (0.001-ha earthen-bottom pools). The
increased growth of fry fed DAC might have been related to differences in
dietary lipid content, amino acid composition, or digestibility of CS and
DAC. Body weights of fingerlings produced under simulated production
conditions from fry fed hatchery diets containing 50% and 75% DAC were 17%
and 25% higher, respectively, 130 d post-hatch, than fingerlings produced
from fry fed only CS. In addition, the total yield of fingerlings produced
from fry fed 75% DAC was 17% greater that that of fingerlings produced from
fry fed only CS. The increased performance of fingerlings produced from
DAC-fed fry could have resulted from their larger size at stocking, since
larger fry might be capable of capturing natural food organisms and
ingesting prepared diets more effectively than smaller fish. CS-DAC diet
combinations could be used to increase weight gain of hatchery-raised fry if
the cost-benefit ratio of adding DAC to the standard hatchery diet warrants
its use.
(Louisiana State Univ, Ctr Agr, 2410 Ben Hur Rd,
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