Acronym NA
Category
Aquaculture
Title Rygg- og kjevedeformiteter hos laks: Genetisk disposisjon, mineralernæring og produksjonstemperatur - Vertebral and jaw deformities in salmon: Genetic predisposition, mineral nutrition and production temperature Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Grete Bæverfjord Coordinator email grete.baverfjord@nofima.no
Coordinator institution
NA
Institutions involved
NA - AquaGen AS (Norway) ,
NA - EWOS Innovation AS (Norway) ,
Start year 2002 End year 2004 Funding (€) € NA Website https://www.fhf.no/prosjekter/prosjektbasen/552092/ Summary "The results from this project have shown a clear effect of mineral nutrition on the development of deformities in the spine and jawbones of salmon. The project demonstrates that feed containing phosphorus at levels aligned with published requirements leads to bone deformities when the fish grow rapidly. This effect is particularly evident for jaw deformities, where the results indicate that jaw drop is induced by limited mineral supply early in the freshwater stage, in combination with high temperature and rapid growth.
The experimental fish originated from a ""tailored"" spawning material consisting of fish with different genetic predispositions for spinal deformities. These fish were fed diets with varying mineral content at different intervals between initial feeding and reaching near slaughter size. The phosphorus content in the experimental diets ranged from 1.1% to 1.2%, consistent with published requirements based on a digestibility of 50% and a feed factor close to 1. In the initial experimental period, up to a size of 20g, a feed containing 70 mg/kg zinc was also used in addition to 1.1% phosphorus. As a control, a feed with extra addition of these two minerals was used. From initial feeding to a size of 20g, the different groups were kept at two different temperatures, 12 and 16°C respectively. The fish were transferred to sea as 0-year smolts in October 2003 and followed until reaching a size of approximately 2 kg.
The results indicate that a phosphorus content in the feed of 1.1% was insufficient to ensure normal bone formation, particularly during the period from initial feeding onwards, when the growth rate was especially high. The vertebrae in fish that received inadequate phosphorus were underdeveloped, small, poorly mineralized, and had abnormal shapes. In these groups, fish with platyspondyly, i.e., flat vertebrae, were observed as the fish increased in size (>1 kg). A significant proportion of the fish exhibited a clear bend in the tail fin. There were also significant occurrences of jaw deformities, with some fish eventually developing jaw drop. These results provide a basis for renewed and intensified efforts to ensure an adequate supply of phosphorus and zinc in feed for salmon."
Keywords
Fish health;
Diets;
Fish;
Salmon;
Genetic;
Marine Region
76
Not associated to marine areas
0
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