Spray-dried blood cells as a partial replacement for fishmeal in diets for rainbow trout Oncorhynchus mykiss.

摘要

Growth of juvenile rainbow trout, Oncorhynchus mykiss (81.4 mm initial length and 6.4 g initial weight), fed a diet containing 47.5% herring meal (FM diet) and a test diet containing 34.5% herring meal and 8.75% spray-dried animal blood cells (SBC diet) was evaluated. Both diets were formulated to be isonitrogenous (48.5 and 48.0% protein) and isoenergetic (3977 and 3927 kcal DE/kg). At the end of the 12-week feeding trial, differences in growth rate and feed conversion ratios were not statistically significant between the two dietary treatments. Apparent CP digestibility was 89.7% for the SBC diet and 88.1% for the FM diet. Apparent net protein utilization and iron retention values were not different, but phosphorus retention was higher for fishfed the SBC diet. Whole body iron content of the fish decreased in both groups from 23.3 mg/kg in an initial sample to 16.5 mg/kg in fish fed the FM diet and 18.4 mg/kg in fish fed the SBC diet at the end of 12 weeks. The diet containing 8.75% SBC replaced 27.4% of the CP supplied by herring meal, and it had 22.7% less total phosphorus (P) than the fish meal diet. The cost of gain for the FM diet was US dollar 0.508/kg gain compared to dollar 0.512/kg gain for the SBC diet.