Effects of Winter Feeding on Growth, Body Composition, and Processing Traits of Co‐Cultured Blue Catfish, Channel Catfish, and Channel Catfish×Blue Catfish Hybrids

Abstract

The effects of winter feeding on growth, body composition, and processing yield were compared for co‐cultured blue catfish Ictalurus furcatus, channel catfish I. punctatus, and channel catfish×blue catfish hybrids. Fish (∼0.4–0.7 kg) from each genetic group were stocked communally at 5,625 fish/ha in ten 0.04‐ha ponds during mid‐November. Fish in five ponds were fed at 2% of initial body weight twice per week; fish in the other five ponds were not fed. The study was terminated after 14 weeks, and fish were weighed and processed. Analyzed traits were weight change (%), survival, and yields (%) of carcass, shank fillet, nugget, head, viscera, skin, intraperitoneal fat, liver, and ovary. Among fed fish, hybrids gained the most weight, channel catfish had intermediate weight gain, and blue catfish gained the least weight. Unfed blue catfish lost more weight than unfed channel catfish and hybrids. Survival was not different among genetic groups or between feeding regimes. Interactions among main effects for processing and body composition traits made generalizations difficult, but carcass yield was consistently higher for blue catfish and hybrids than for channel catfish, higher for females than for males, and higher for fed fish than for unfed fish. Shank fillet yield was higher for hybrids than for blue catfish and channel catfish, higher for females than for males, and higher for fed fish than for unfed fish. Nugget yield was higher for blue catfish than for channel catfish and hybrids and was higher for fed fish than for unfed fish. Blue catfish and hybrids had higher intraperitoneal fat yield and lower liver and ovary yield than channel catfish. Fed fish had higher intraperitoneal fat and liver yield than unfed fish. Winter feeding improved growth and fillet yield in all groups, but the benefits of winter feeding were lower for blue catfish than for channel catfish and hybrid catfish.

No Evidence for Intercohort Cannibalism in Mixed‐Size Cultures of Food‐Size and Fingerling Channel Catfish × Blue Catfish Hybrids Grown in Ponds

“…Weight loss of (nonfed) food-size carryover fish over winter averaged approximately 1% of body weight. This compares reasonably well with Bosworth (2012) who observed a 0.4% loss of body weight in 0.4-0.7-kg hybrid catfish held without supplemental feed overwinter. The slightly greater loss in body weight we observed is probably due to the longer period in nonfed status (121 d versus 102 d for Bosworth).…”

Environment-Dependent Heterosis and Transgressive Gene Expression in Reciprocal Hybrids between the Channel Catfish Ictalurus punctatus and the Blue Catfish Ictalurus furcatus

“…Researchers evaluated 42 different interspecific ictalurid catfish hybrids by crossing two distinct species. Only the combination of channel catfish ( Ictalurus punctatus ) female × blue catfish ( Ictalurus furcatus ) male (C×B hybrid) has superior feed conversion efficiency [ 41 , 42 ], higher carcass yield [ 43 ], better tolerance to low oxygen [ 44 ], improved disease resistance [ 45 ], and enhanced harvestability [ 46 ] to market size. Collectively, these characteristics exhibiting heterobeltiosis enable a commercial production rate of 13,000 kg ha −1 , which doubles the yield of traditional channel catfish farming [ 42 , 47 , 48 ].…”

Effect of Grading Fingerling Hybrid Catfish (♀ Channel Catfish × ♂ Blue Catfish) on Growth, Production, Feed Conversion, and Food Fish Size Distribution

“…This is unlikely to impact hybrid catfish production because hybrids do not show similar sex‐related growth differences and are usually harvested before sexual maturity, which could result in processing yield differences (Bosworth et al. ; Bosworth ).…”