Location: Warmwater Aquaculture Research UnitTitle: Effects of long-term restricted feeding followed by full feeding on growth, processing yield, fillet proximate composition, and economics of market-size hybrid catfish, ¿ Ictalurus punctatus × ¿ Ictalurus furcatus
|LI, MENGHE - Mississippi State University|
|WISE, DAVID - Mississippi State University|
|KUMAR, GANESH - Mississippi State University|
|MISCHKE, CHARLES - Mississippi State University|
|AARATTUTHODIYIL, SUJA - Mississippi State University|
|RUTLAND, BILLY - Mississippi State University|
|LUCAS, PENELOPE - Mississippi State University|
Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2020
Publication Date: 7/17/2020
Citation: Li, M., Wise, D., Kumar, G., Bosworth, B.G., Mischke, C., Aarattuthodiyil, S., Rutland, B., Lucas, P. 2020. Effects of long-term restricted feeding followed by full feeding on growth, processing yield, fillet proximate composition, and economics of market-size hybrid catfish, ¿ Ictalurus punctatus × ¿ Ictalurus furcatus. Journal of the World Aquaculture Society. 51(4):931-943. https://doi.org/10.1111/jwas.12727.
Interpretive Summary: Meat yield, the percentage of whole fish weight comprised on saleable meat, is an important trait in farm-raised catfish and diet composition and feeding regimes can affect meat yield. Catfish farmers are sometimes unable to sell market weight catfish for processing due to lack of demand in the supply chain causing issues with production management. If the fish are fed during this time, they grow larger than the preferred-size for processing and the price paid to farmers is reduced substantially. If the fish are not fed, they mobilize muscle tissue for energy and fillet yield is decreased and the price paid to farmers is reduced. WARU scientists worked in cooperation with Mississippi State University (MSU) fish nutritionists to determine that the majority of hybrid catfish fed once or twice weekly for four months remained in the preferred-size for processing but had decreased fillet yield. Thirty days of full feeding were needed to restore fillet yield to normal levels in fish were fed once or twice weekly for four months, however re-feeding for 30 days for fish previously fed twice per week resulted in a high percentage of fish being over the preffered size range and reduced profits. Results from these studies are provided to catfish producers and processors and allow the catfish farming industry to develop feeding strategies to minimize production costs and maximize profits.
Technical Abstract: A pond study examined the effects of long-term restricted feeding followed by full feeding on production and processing characteristics, fillet composition, and economics of marketsize hybrid catfish, ' Ictalurus punctatus × ' Ictalurus furcatus. Market-size fish averaging 674 g were stocked into 24 ponds (0.04 ha) at 17,300 fish/ha. Fish were either fed once or twice weekly for four months or once or twice weekly for four months followed by 15- or 30-day daily full feeding. All fish were fed to apparent satiation on days fed. Fish fed once weekly for four months gained about 30% weight and those fed twice weekly gained 70% weight. Feeding once or twice weekly for four months followed by 15- or 30-day full feeding did not significantly affect carcass yield compared with the initial sample (overwintered fish). At least 30 days of full feeding were needed to restore fillet yield to normal levels. Based on economic analysis and processing yield, it is suggested fish fed once weekly should be given full feed for 15 days or so to improve fillet yield before harvest. Fish fed twice weekly can be harvested with or without 15 days full feeding.