Publisher: Nofima AS
Number of pages: 43
International Standard Numbers:
Open Access: green
An experiment was conducted to study the utilization efficiency of P from fish bone hydrolysate (FBH) relative to a Na -P salt in Atlantic salmon fry. A low P diet (0.55% soluble P) was compared with FBH and Na-P at two levels (0.70% and 0.85% soluble P) in triplicates from start feeding until 30 g size. The results were evaluated based on growth, mortality, mineral analysis and X-ray, and by histopathology, FTIR, transcriptomics (qPCR) and enzymes (ALP, TRAP). Fish fed a low P diet showed clear P-deficiency signs. Fish fed FBH1 showed some small differences in histology, FTIR and gene expression in the bones of 15g fish corresponding to findings in the low P diet. This was not found for FBH2. Overall, results indicated that P hydrolyzed from the bone fraction of herring trimmings can be effectively utilized to maintain normal growth, mineralization and bone development of salmon fry, but that the availability of P may be slightly lower than that of Na–P in the early salmon fry stage until the fish reaches approximately 15 g size.