Two commercial trout diets, Pro-Form Trout Grower and BioDry Trout, were fed to domestic rainbow trout, and comparisons were made for differences in growth, survival and cost. For the study, fish were stocked into Sayres Lake net pens (SNP) at an average weight of 25 g and reared for four months, October 22, 1992 to February 22, 1993. They were then released into urban lakes as catchable trout (approximately 150 g). After 17 weeks on the test diets, fish fed Pro-Form Trout Grower were significantly larger in both weight and length than fish fed BioDry Trout. During the experiment, total mortalities for the two diets were both <3% (Pro-Form 1.3%; BioDry 2.6%), which from a production standpoint is acceptable. The total cost of feeding Pro-Form Trout Grower was 30% less than BioDry Trout for this experiment. This study found that feeding Pro-Form Trout Grower to domestic rainbow trout at SNP produced more biomass of fish at a lower cost per unit for a similar survival and quality of product.
Lawson, Charlotte. 1996. Evaluation of Two Commercial Diets for Domestic Rainbow Trout. Ministry of Environment, Lands and Parks. Fisheries Technical Circular. FTC97