Protein requirements of Arctic charr / Protein requirement of char
Five different feed types with protein content from (29) 30 - 40% were given in two size groups (100 g and 600 g) in both fresh and salt water. The effects of different feeds were assessed on the basis of their effects on digestibility, weight development, daily growth (SGR), feed utilization (FCR), chemical composition of fillets (in the larger fish) and sensory evaluation. Final weight and daily growth were lowest in the fish fed the lowest protein, but no effect of protein, in excess of 37% in the feed, was found on final weight and SGR. The minimum protein requirements for growth are therefore between 33% and 38% in the feed. There was no significant difference in feed response between size groups, even though the effect of reduced protein was greater in the larger fish. It was also not possible to see a single decisive effect of salinity on the protein requirement. The protein content of the feed also did not have a decisive effect on the fillet composition or sensory evaluation of the products.
Four (five) different diets with protein varying from (29) 30 - 41% were fed ad libitum to two size groups of Arctic charr (100 gram and 600gram) in fresh‐ as well as seawater. The effect of the different diets was evaluated by digestibility, weight development, SGR, FCR, chemical composition of filet (in the bigger size groups) and sensory evaluation. The lowest final weights and SGR were found when fed the diets with lowest protein but here was no effect final weight and final weight between 38% and 41% protein in the diet, indicating that the minimum need for protein is between 33 and 38% protein in the diet . The same trend was shown in both size groups but the effect was more pronounced in the bigger fish than in the smaller fish. The results regarding size and growth were also the same in fresh‐ and seawater. The protein content in the diet did not have any marked effect on either chemical composition of filets or the sensory quality of the product.