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

摘要

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