Title: Differential carbohydrate utilization by genetic groups of striped bass Authors
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2010
Publication Date: February 28, 2011
Citation: Fuller, S.A., Rawles, S.D., Mcentire, M.E., Freeman, D.W. 2011. Differential carbohydrate utilization by genetic groups of striped bass [abstract]. Book of Abstracts Aquaculture America. p.168. Technical Abstract: The capacity of different fish to use carbohydrate varies substantially, and Morone do not use carbohydrate well. To date, there have been no studies initiated to determine correlation between carbohydrate utilization and genetic origin on striped bass (Morone saxatilis). Striped bass were screened with ten microsatellite markers and were partitioned into genetic groups based on pairwise relatedness. Eight to nine striped bass (mean weight = 390 g) from 18 genetic groups were assigned to one of two dietary starch inclusion levels (15 and 35% starch) and reared in replicate 600-L round tanks (4 tanks/treatment) and fed their respective diets to apparent satiation twice a day. All diets were isonitrogenous (35% digestible protein) and isolipidic (12% digestible lipid) with increasing levels of energy provided by starch. At the conclusion of the 12 week feeding trial, all striped bass were weighed and sacrificed for determination of carcass characteristics (% muscle, % ribbon fat, hepatosomatic index). Overall, increasing carbohydrate level led to significantly higher HSI and fat percentage, significantly lower weight gain, but had no effect on percentage of muscle. There were significant differences (P < 0.05) in weight gain among the genetic groups within each diet. Additionally, there were significant differences in percent fat among the genetic groups fed the low carbohydrate diet not found in the high carbohydrate treatment. There were also significant differences in percent muscle among the genetic groups fed the high carbohydrate diet not found in the low carbohydrate treatment. The same genetic group had the highest weight gain regardless of diet. Pairwise comparisons identified one genetic group with significantly higher growth on a high carbohydrate versus low carbohydrate diet. These results demonstrate the influence of carbohydrate level on relative performance of genetic groups of striped bass. With sufficient phenotypic variation present, a selective breeding program could be implemented to improve the performance of striped bass fed a higher carbohydrate diet by selecting individuals or families better able to utilize the higher energy content of these diets.