Influence of feeding rate on performance of Atlantic salmon fry in an ozonated water reuse system

A 4‐week trial was conducted to determine the optimal feeding level in percent body weight of a commercially prepared, practical diet for early feeding fry of Atlantic salmon (Salmo salar) in an ozonated water reuse system at 17–18°C. Triplicate groups of swimup (0.19‐g) fry were fed one of seven levels of Biodiet starter diet calculated for hatchery constants of 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, and 8.5. Feeding levels (percent body weight) were derived at the start of the study and again at 2 weeks by dividing mean body length, in inches, into the respective hatchery constant. Mean body weight and body fat content increased significantly with each increment in level of feeding through a hatchery constant of 6.5. after which there was no further increase. Body protein decreased as feeding increased through hatchery constant 6.5; ash content decreased through hatchery constant 5.5. Results indicated that young Atlantic salmon fed at low feeding rates (2.47–5.44% body weight) in the water reuse system were underfed, but fish fed at 5.46–8.41% body weight grew at a favorable rate.