Mineral requirements in fish. I. Effects of dietary salt-mixture levels on growth, mortality, and body composition in rainbow trout and carp.

Abstract

Diets containing graded levels of salt-mixture (McCOLLUM's salt-mixture no. 185 plus trace elements) were given to young rainbow trout and carp for 50 days. Dietary levels of the salt-mixture exerted a strong influence on growth and mortality in rainbow trout and on growth in carp. Rainbow trout were more sensitive to the lack of the dietary salt-mixture than carp. The diet deficient in the salt-mixture resulted in retarded growth, high mortality, anemia and malformation of the head in rainbow trout. The optimal content of the salt-mixture in the diet was proven to be 4 to 5% for both species under the present experimental conditions.