| dc.description.abstract | Improvements in production efficiency of aquaculture are necessary to provide seafood to feed a growing human population. Therefore, a series of studies were conducted to evaluate two different means of improving growth and production efficiency of several fish species.
The first study evaluated forced swimming as a means to improve growth of hybrid striped bass, red drum, and tilapia. Each species was subjected to a water current of 1 body length per second (bl/s) and compared to controls in static water for 7 weeks. Results indicated that continuous swimming beneficially affected aspects of tilapia and red drum growth and altered their body composition. Reduced growth was observed in hybrid striped subjected to flowing water, possibly due to consistently wary feeding behavior.
A second study, consisting of seven separate comparative feeding trials evaluated dietary creatine on channel catfish, hybrid striped bass and red drum under different salinity conditions which could influence the energetics of osmoregulation. In channel catfish fry, growth performance improved with supplemental creatine (2% of diet) over an 8-week feeding period at 8 ppt salinity. In another trial, there were no discernable differences in growth performance of catfish fry during a freshwater (2 ppt) phase, but there were significant improvements in survival of catfish in the brackish water (10 ppt) phase. In both trials, muscle creatine levels significantly increased with dietary supplementation.
Another 12-week, two-part feeding trial was conducted to evaluate dietary creatine supplementation on hybrid striped bass under different water salinity. During the low salinity (5 ppt) phase, there were no discernable differences in growth performance of juvenile hybrid striped bass. However, significant improvements in weight gain were found in fish fed the diets supplemented with 2% and 4% creatine during the brackish-water (15 ppt) phase.
To evaluate dietary creatine supplementation in red drum, four separate feeding trials were conducted at various salinities. Significant improvements in growth performance were detected in juvenile red drum in all trials. A minimum creatine supplementation of 1.98% of diet provided optimal weight gain of red drum. Thus, this dissertation identified two different means of improving growth efficiency of three different fish species. | en |
