Author
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Small, Brian |
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Submitted to: Aquaculture America Conference
Publication Type: Abstract Only Publication Acceptance Date: 10/14/2005 Publication Date: 2/13/2006 Citation: Small, B.C. 2006. Improvements in channel catfish growth after two generations of selection and comparison of performance traits to blue catfish and hybrid catfish fingerlings in an aquarium rack system. Aquaculture America Conference 2006, Las Vegas, NV. p. 292. Interpretive Summary: Technical Abstract: The majority of catfish grown and sold in the United States for human consumption are channel catfish (Ictalurus punctatus). In recent years, a slow economy and the threat of foreign fish imports to the profitability of US catfish farming has prompted renewed interest in the blue catfish (I. furcatus) as well as increased efforts in genetic improvement of channel catfish and hybridization between channel and blue catfish (I. punctatus female x I. furcatus male). Aquarium rack systems provide a means of maintaining large numbers of juvenile fish in a very small footprint. The utilization of such systems in a breeding program could greatly expand the capacity for conducting performance comparisons of a large number of genetic groups. The purpose of this study was to assess the response of two generations of selection for increased body weight in channel catfish, and compare fingerling performance of channel, blue, and hybrid catfish in an aquarium rack system. A 9-week growth study was conducted comparing USDA103 and USDA303 lines of channel catfish to blue and hybrid catfish in an aquarium rack system (ARS). Differences in growth indices, feed and protein efficiency, nitrogen retention, whole-body proximate composition, and plasma cortisol levels were determined at the completion of the study. USDA303 channel catfish gained significantly more weight and consumed more feed than each of the other genetic groups. Feed and protein efficiency were similar for USDA103, USDA303, and hybrid catfish, but were lower for blue catfish. Nitrogen retention was highest for hybrid catfish and lowest for blue catfish. No differences in final body composition were observed between genetic groups when final weight was used as a covariate. Plasma cortisol levels after 9 weeks ranged from 9.7 ng/mL in blue catfish to 24.5 ng/mL in USDA103 channel catfish, but were not significantly different between genetic groups. This study demonstrates improved growth of the USDA303 channel catfish after two generations of selection for increased body weight, and reports significant differences in performance among channel, blue, and hybrid catfish in an aquarium rack system. |
