Title: Response of sunshine bass to ration at elevated culture temperature Authors
|Gaylord, Thomas -|
|Barrows, Fredrick -|
Submitted to: International Congress on the Biology of Fish
Publication Type: Abstract Only
Publication Acceptance Date: May 18, 2012
Publication Date: July 15, 2012
Citation: Rawles, S.D., Green, B.W., Gaylord, T.G., Barrows, F.T., Mcentire, M.E., Freeman, D.W. 2012. Response of sunshine bass to ration at elevated culture temperature [abstract]. 10th International Congress on the Biology of Fish, July 15-19, 2012, Madison, Wisconsin. p.105. Technical Abstract: Temperature and ammonia increase dramatically during summer production of sunshine bass. Global temperatures are projected to increase. A factorial experiment investigated the effects of three digestible protein (DP; 33, 40, 47%), two lipid (L; 10, 18 %) and two ration levels (satiation, restricted) on growth, body composition, nutrient retention, and ammonia excretion in bass reared at 30.5C. Restricted feeding resulted in lower final weights and percent gains but higher ammonia excretion as a function of N fed/body-weight regardless of DP. Lower dietary fat (10%) resulted in lower weight gains, poorer feed conversions and higher ammonia excretion regardless of DP or ration. Weight gain was marginally higher at 47DP/18L, but FCR, and nutrient retentions were markedly poorer in the 47DP diets regardless of lipid level due to hyperphagia in these fish. At 30.5C, the 40DP/18L diet outperformed other diets in growth, lower ammonia excretion and higher nutrient retentions regardless of ration. Producers desiring to manage ammonia during summer with least compromise to production are better served to feed a 40DP/18L diet at reduced ration instead of lower protein/lipid diets.