UBC Theses and Dissertations
The effect of cycle period, ration level and repetitive cycling on the compensatory growth response in rainbow trout, Salmo gairdneri Richardson Quinton, John Chadwick
Compensatory growth is the phase of rapid growth, greater than normal or control growth, which occurs upon adequate refeeding following a period of undernutrition. The effect of cycle period (length of the starvation and following refeeding periods), ration level and repetitive cycling (repetition of cycle periods) on the compensatory growth response in rainbow trout, Salmo gairdneri Richardson were evaluated in two experiments. A cycle period of three weeks produced better results in terms of average percentage changes in weight and length and in specific growth rate than either one or two week cycle periods. There was no significant difference between the cyclically fed fish and a constantly fed control group. Three ration levels were compared using a three week cycle period and the only effect of increased ration was to decrease conversion efficiency. There were no significant differences in the average weight of control and experimental groups after six or twelve weeks of continuous cycling thought the controls had been fed more than twice as much food. Carcass analysis of moisture, fat, protein and ash showed no significant differences between the controls and experimental group after one complete cycle. Possible mechanisms underlying the compensatory growth response are discussed.
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