Relationships between dietary sodium chloride, food intake and food conversion in the rainbow trout

The addition of up to 8.5 % sodium chloride to the diet of rainbow trout Salmo gairdneri had no significant effect on either food intake or food conversion efficiency. Over a range of rations from 4 % to 38 % of dry weight per week, there was a rectilinear relationship between ration and growth rate. The weight maintenance requirement and rate of weight loss during fasting were estimated from this relationship. Food conversion efficiency ( K ) increased from 0.00 at 4% dry weight per week food intake ( x ) to 0.19 at 38%, according to the equation K =0.21-0.77/x.