Location: Aquatic Animal Health ResearchTitle: Evaluation of traditional diet and corn gluten feed substituted alternative diet for pond-raised hybrid catfish on production and xanthophyll level Author
|Davis, D. Allen|
Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2012
Publication Date: 5/4/2012
Publication URL: http://handle.nal.usda.gov/10113/55477
Citation: Hu, B., Ferrell, M., Lim, C.E., Davis, D. 2012. Evaluation of traditional diet and corn gluten feed substituted alternative diet for pond-raised hybrid catfish on production and xanthophyll level. Aquaculture. 354-355:22-26. Interpretive Summary: The increasing price of common feed ingredients and the relatively unchanged whole catfish price have led to the decrease of the catfish farmers' profits. To minimize feed price increases, low-cost alternative feed ingredients need to be evaluated. Although some studies have indicated that appropriate formulated catfish feeds with alternative ingredients can result in a statistically no different production from traditional feed, more research is still needed to evaluate feed formulations with alternative feed ingredients. Corn processing byproducts, such as corn gluten meal and corn gluten feed, due to their lower costs are good alternative ingredients substitutes. However, because corn products contain high concentrations of yellow pigments, the use of these ingredients may lead to increased pigment content in the feed and consequently incidences of yellow fillets. Yellow fillets have become a quality control and consumer problem. Thus, this study was conducted to evaluate the effect of inclusion of 20% corn gluten feed to traditional 28 and 32% protein feed on the production, blood parameters and fillet color of channel-blue hybrid catfish. Fish with an average weight of 34.5 g were stocked in 0.04 ha at 600/ponds. Fish in each of the five replicates ponds were fed each of the four floating test diets (28 and 32% protein with or without 20% corn gluten feed) to apparent satiation once daily on the morning over a summer growing season. Fish yield, feed intake feed conversion ratio, survival dressout percentage did not differ among fish fed different feeds. Interperitoneal fat was generally lower in fish fed feeds containing corn gluten feed. There were no differences among blood parameters, serum immune responses and fillet pigment content in fish receiving different treatments. Thus, all four experimental diets tested can be efficiently utilized by channel-blue hybrid catfish resulting with satisfying production with acceptable hematology, immune response and without fillet color.
Technical Abstract: In the United States, catfish industry is a mature industry with a long history of success. However, the industry faces numerous challenges while it evolves and adapts to shifting inputs and market demands, such as the dramatic increase in the price of feed ingredients and requests for more consistent fillet color. There is considerable interest in reducing the cost of production diets either by reducing the protein content or by using alternative ingredients such as corn gluten feed. Towards this goal, a pond study was conducted to evaluate the utilization of alternative feed containing 20% corn gluten feed compared to traditional feed without corn gluten feed for the production of channel-blue hybrid catfish. Both alternative and traditional feeds were formulated with two protein contents (28% and 32%). In addition to traditional parameters, the xanthophyll contents on the fish fillets were determined. Upon initiation of the pond trial, 600 hybrid catfish fingerlings were stocked in each of 20 0.04-ha ponds, with a mean weight of 34.5 g/fish. Fish were fed four experimental diets once daily to apparent satiation over a summer growing season. No significant differences were found in growth performance and feed utilization among the four treatments, including gross and net yield, total amount of feed fed, estimated feed conversion ratio and survival. No significant differences were found in mean individual fish weight and mean total body length at harvest, relative weight index and dressout (headed and gutted). However, intraperitoneal fat ratio was significantly lower in fish fed the alternative feeds indicating lower energy content of the diet. No significant differences were observed in hematology and immune response indices. Xanthophyll levels in diets and in fillet were linearly related, but without discernible yellow color. These data generally indicate that channel-blue hybrids can efficiently utilize all the four experimental diets with satisfying production result.