Growth and Feed Efficiency of Channel × Blue Catfish Hybrids Stocked at Various Densities and Fed Once or Twice Daily in Ponds

Abstract

Two experiments were conducted to evaluate the effects of stocking density and feeding frequency on the growth, net yield, and feed conversion of hybrid catfish (female channel catfish Ictalurus punctatus × male blue catfish I. furcatus). In experiment 1, hybrid catfish fingerlings with a mean initial weight of 65 g were stocked into ten 0.4‐ha earthen ponds at a density of 12,355 fish/ha. In experiment 2, hybrid catfish fingerlings with the same mean initial weight as in experiment 1 were stocked into twenty 0.4‐ha earthen ponds at densities of 18,532 and 24,710 fish/ha, respectively. Fish were fed once or twice daily to apparent satiation. In experiment 1, all fish were harvested in early September. In experiment 2, market‐size fish (target size, ≥0.794 kg/fish) were selectively harvested in late September by means of an in‐pond mechanical fish grader with the bar spacing set to 5.4 cm. All remaining fish were harvested in mid‐June the next year. In both experiments, fish fed twice daily were given more feed, but there were no significant differences in weight gain per fish and net yield between fish fed once daily and those fed twice daily. Fish fed twice daily had a significantly higher feed conversion ratio. In experiment 2, a stocking density of 18,532 fish/ha resulted in higher weight gain and lower net yield than a stocking density of 24,710 fish/ha. Based on the results from this study, it appears to be efficient to stock hybrids at a density of 12,355 fish/ha, feed them once daily over a growing season, and “clean” harvest them at the end of the season. However, a multiple‐batch system may also be used to grow hybrids at densities of 18,532–24,710 fish/ha by means of a catfish grading system to remove market‐size fish.

Effects of Stocking Density on Production Traits of Channel Catfish×Blue Catfish Hybrids

“…Direct comparison of hybrid catfish production traits reported in this study with other reports in the literature is difficult due to differences in study design (e.g., duration, cropping system, management practices), but the values for harvest weight (∼0.80 kg), survival (>93%), FCR (∼2.0), and net production (6,135-16,492 kg/ha) were good and compare favorably with other reports for production of hybrid catfish in single-batch production (Dunham et al 1990;Bosworth et al 2004;Green and Rawles 2010;Li et al 2010). Carcass and fillet yield reported in the current study were lower than values reported for hybrid catfish by Bosworth et al (2004), Li et al (2007), Jing et al (2008, and Bosworth (2012), but similar to those reported by Li et al (2012).…”

“…Ammonia and nitrite can negatively affect growth and survival of catfish in tank studies (Colt and Tchobanoglous 1978;Colt et al 1981), but sublethal effects of nitrogenous waste products on catfish production in earthen ponds are more difficult to demonstrate consistently (Hargreaves and Tomasso 2004). Li et al (2010) observed an 18% decrease in hybrid catfish harvest weight when density increased, but no difference in ammonia nitrogen at different densities. Torrans (2008) and Green and Rawles (2011) reported growth suppression of Channel Catfish raised under low DO compared with high DO conditions, but no relationship between growth and ammonia levels.…”

“…In the current study, we did not observe an effect of stocking density on hybrid catfish FCR or survival at any density, and harvest weight was not affected until the maximum stocking density of 27,225 fish/ha. Li et al (2010) reported an 18% decrease in harvest weight of hybrid catfish when stocking density increased from 18,532 to 24,710 fish/ha. Although different stocking densities were used we observed a decrease of only 11% in growth when the stocking density increased from 17,325 to 27,225 fish/ha.…”

“…The effect of stocking density on production has been the topic of considerable research with Channel Catfish (Allen 1974;Tucker et al 1993;Engle and Valderrama 2001;Pomerleau and Engle 2003;Southworth et al 2006;Robinson and Li 2008;Green 2010;D'Abramo et al 2013) and to a much lesser degree with hybrid catfish (Dunham et al 1990;Li et al 2010). Generally individual growth rates of Channel Catfish decrease with increased stocking density, and although net production typically increases as stocking density increases, the increase in net production is proportionally less than the increase in stocking density resulting in a lower average weight at harvest as stocking density increases.…”

Effects of Feeding Rate and Frequency on Production Characteristics of Pond‐Raised Hybrid Catfish

“…With growing interest in hybrid catfish production, knowledge of optimum feeding rates and frequencies would assist hybrid growers in better management of hybrid production, and thus improve production efficiency and profit. Li et al (2010) evaluated feeding hybrid catfish once or twice daily during food fish grow out and found that feeding once daily provided satisfactory growth. There was no benefit to feeding hybrid catfish twice daily.…”