The trials, conducted on fish from 1 to 5 kg, showed excellent growth and a low feed conversion rate (FCR) on salmon given feed with 15 per cent fishmeal and no land animal protein, reports SkrettingNews.
Dr Alex Obach, Managing Director of Skretting ARC, gives some details. "We used three feeds and the best results came from an experimental feed using only 15 per cent fishmeal together with active ingredients we are currently investigating. The two other feeds were a more conventional feed with 25 per cent fishmeal and a similar experimental feed using 15 per cent fishmeal but without the active ingredients.
The results totally change our previous belief that the lower limit for fishmeal was 25 per cent unless land animal proteins were used. At present, that is not possible for salmon production in Europe." The trials were conducted at Skretting ARC Fish Trials Station and Helgeland Havbruksstasjon, both located in Norway. The trial at Helgeland used three groups of 180 fish starting at around 2.6 kg. Over the 73 days they grew to around 4.7 kg.
All three groups of fish showed excellent performance. The high fishmeal (25 per cent) control group achieved a relative growth index (RGI) of 169 per cent (specific growth rate/SGR=0.85 per cent/day), however, the group fed the feed with 15 per cent fishmeal plus active ingredients achieved an RGI of 172 per cent (SGR=0.87 per cent/day).
The group fed the basic 15 per cent fishmeal feed recorded an RGI of 152 per cent (SGR=0.76 per cent/day). The reduction in fishmeal showed no negative effects on fish quality and monitoring throughout the trials also showed the fish maintained a good health status. FCR was below 1 for all groups.
Dr Obach adds, "It is the first time we have achieved such good results in growth and FCR with low fishmeal feeds without using land animal proteins. Although Skretting will not implement the results yet in commercial feeds, they demonstrate a significant potential for extending our use of sustainable fishmeal over a much greater production of farmed Atlantic salmon. Around two-thirds more salmon could be grown from the same volume of fishmeal."