Genetics, Physiology, and Health Research to Improve Catfish Production
Location: Catfish Genetics Research
Title: Effect of strain and diet on growth performance characteristics and relative expression of genes coding for electron transport chain in channel catfish
Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 3, 2011
Publication Date: February 1, 2012
Citation: Eya, J.C., Ashame, M.F., Manning, B.B., Peterson, B.C. 2012. Effect of strain and diet on growth performance characteristics and relative expression of genes coding for electron transport chain in channel catfish. Aquaculture America Conference. P. 148.
The major cost in aquaculture production systems is feed, and the use of biotechnology approaches to identify fishes with superior feed efficiency (FE) may have a positive influence on profitability. There been little use of genetically based technologies to assess FE in culture fishes. Mitochondria, called the “powerhouse of cells” have the capability of transforming energy into a form that is usable by cell parts. In some animals, such as broilers and rats, mitochondrial function has been associated with FE. Identifying cultured fish with superior mitochondrial function, i.e., the ability to convert feed into meat (weight) could provide advantages and improved efficiencies in aquaculture production. A 2 x 4 factorial experiment was conducted to evaluate the effects of strains and diet on channel catfish performance and mitochondrial gene expression levels in the liver, muscle and intestine. A 13-week feeding trial was conducted at USDA/ARS Catfish Genetics Research Unit, Stoneville, MS, USA. Two strains, Delta Select (pooled group of fish collected from the MS Delta) and USDA103 strains of channel catfish were selected and stocked into 76 L tanks (20 fish/tank). Fish were fed with four different diets 32% crude protein (CP) diet with fishmeal; 32% CP diet with no fishmeal (all plant protein); 28% CP diet with fishmeal and 28% CP diet with no fishmeal (all plant protein). The amount of fat in each diet was kept constant at approximately 2 % and there were four replicate tanks per treatment for a total of 32 tanks. Results indicate that feed intake, expressed as percent body weight gain per day, was significantly (P<0.05) different between USDA 103 and the Delta Select strain. USDA 103 consumed a higher amount of feed and had better weight gain and specific growth rate when compared to Delta Select. USDA 103 had a numerically higher value for FE, though not significantly (P = 0.54) different from the Delta Select. Dietary composition had significant main effect on feed consumption, weight gain, SGR and FE (P = 0.006). There were no interactions for these variables among dietary composition and strain. Significant differences were seen between the channel catfish strains and the different diets in the relative expression of the mitochondrial genes in the liver, intestine and muscle and there were variations in the interactions between diet and strain in different tissues. Our study indicates that diet has an important impact on channel catfish production and that a practical diet containing 32% CP with no fishmeal is better than diet containing 28% CP with no fishmeal and is as good as diets containing 28% and 32% CP with fishmeal for enhanced growth performance.