Dietary protein requirement of juvenile sunshine bass at different salinities Academic Article uri icon

abstract

  • Three feeding trials were conducted to determine the dietary protein requirement of juvenile sunshine bass Morone chrysops M. saxatilis . In the first feeding trial, semipurified diets were formulated with menhaden fish meal to contain graded levels of protein ranging from 25 to 55% of dry diet. Each diet was fed to triplicate groups of sunshine bass initially weighing 2.68 0.09 g/fish (mean SD) in a closed recirculating system containing. At the end of 8 weeks, nonlinear least-squares regression analysis indicated that protein levels of 40.8 and 43.1% of dry diet were required for optimal growth and feed efficiency, respectively. In the second feeding trial, similar diets (3050% protein) were fed to triplicate groups of fish initially weighing 6.45 0.25 g/fish in a recirculating system containing artificial seawater at a salinity of 32. Growth at this salinity was severely restricted regardless of dietary protein level. Thus, after 4 weeks, salinity was reduced to 7 for a third feeding trial, which continued for 6 weeks. Subsequently, specific growth rates of sunshine bass fed all diets increased significantly. Nonlinear parameter estimates for optimal growth were 40.0% dietary protein for the second feeding trial, and 38.1% dietary protein for the third feeding trial. Based on these data, the dietary protein requirement of juvenile sunshine bass for optimal growth was approximately 41% of dry diet in both fresh and brackish water. Protein efficiency ratio and protein conversion efficiency values were inversely correlated with dietary protein level. Hepatosomatic index and intraperitoneal fat ratio values were also inversely related to dietary protein. Although significant differences in body composition data from the first and last feeding trials were limited within trials, whole-body protein, ash, and moisture generally increased and lipid decreased with increasing dietary protein. 1992 Taylor & Francis Group, LLC.

published proceedings

  • Progressive Fish-Culturist

author list (cited authors)

  • Brown, M. L., Nematipour, G. R., & Gatlin, D. M.

complete list of authors

  • Brown, ML||Nematipour, GR||Gatlin, DM

publication date

  • January 1992