Location: Warmwater Aquaculture Research UnitTitle: Use of corn germ meal in diets for pond-raised channel catfish, Ictalurus punctatus Author
Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2012
Publication Date: 4/1/2013
Citation: Li, M.H., Robinson, E.H., Oberle, D.F., Lucas, P.M., Bosworth, B.G. 2013. Use of corn germ meal in diets for pond-raised channel catfish, Ictalurus punctatus. Journal of the World Aquaculture Society. 44:282-287. Interpretive Summary: Corn and wheat middlings have typically been the most commonly used energy feedstuffs in commercial channel catfish diets in USA, primarily because they were relatively inexpensive and readily available throughout the growing season. However, these ingredients, especially corn, have become more expensive in recent years, and thus, there is interest in using less expensive alternative energy feedstuffs. Corn germ meal (CGM) is an alternative ingredient that appears to be suitable for use in catfish diets, and it is competitively priced relative to corn and wheat middlings. It is a by-product of corn milling and consists of ground corn germ with other parts of the corn kernel from which most of the oil has been removed. A study was initiated to evaluate effects of various levels of CGM in the diet on production characteristics, processed yield, and body composition of channel catfish in earthen ponds. Results demonstrate that channel catfish can utilize CGM at levels up to 35% of the diet without adversely affecting diet consumption, weight gain, FCR, and fillet proximate nutrient composition. However, carcass yield generally decreased as CGM levels increased. Depending on prices, CGM can be used interchangeably with CGF in diets for pond-raised channel catfish during food fish grow out.
Technical Abstract: Corn germ meal (CGM) is a by-product of corn milling. On the basis of its nutrient composition and digestibility values, it appears to be a suitable ingredient for use in channel catfish, Ictalurus punctatus, diets. A study was conducted to examine the use of various levels of CGM in diets for pond-raised channel catfish. Four 28% protein diets containing 0, 15, 25, and 35% CGM were evaluated. Fingerling channel catfish (mean initial weight: 71 g/fish) were stocked into 24, 0.04-ha ponds at a rate of 14,826 fish/ha. Fish were fed once daily to apparent satiation for a 167-d growing season. No significant differences were observed in total amount of diet fed, diet consumption per fish, net yield, weight gain, feed conversion ratio, survival, fillet yield, and fillet protein, fat, and moisture concentrations among fish fed diets containing various levels of CGM. Carcass yield decreased linearly as dietary CGM levels increased. Depending on prices, CGM can be used interchangeably with corn gluten feed in channel catfish diets as replacements for corn, wheat middlings, and soybean meal to reduce feed cost.