Submitted to: International Journal of Aquatic Research and Education (IJARE)
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/2/2013
Publication Date: 4/26/2013
Citation: Burr, G.S., Wolters, W.R., Barrows, F., Donkin, A.W. 2013. Evaluation of a canola protein concentrate as a replacement for fishmeal in a commercial production diet for Atlantic salmon. International Journal of Aquatic Research and Education (IJARE). 5:5-13. Interpretive Summary: Atlantic salmon is a good source of protein that contains high levels of heart healthy omega-3 fatty acids. However, Atlantic salmon culture has been criticized as being detrimental to certain wild fish populations, since these are caught to make fish meal. Fish meal is a major source of protein in aquafeeds. This study looked at replacing fish meal with canola protein concentrate in a commercial production feed. Canola typically has several anti-nutritional factors that slow growth in fishes. We used canola protein concentrate because most of these compounds should be removed in the refining process. Fish fed the canola protein concentrate free diet had the greatest growth while fish fed the 20% canola protein concentrate diet had the least growth. Salmon fed the 10% canola protein concentrate diet had intermediate growth that was not significantly different from the canola protein concentrate free diet. These results suggest that canola protein concentrate can only be included in the diet at or below 10%.
Technical Abstract: Atlantic salmon (Salmo salar) is an important aquaculture species with 11,000 MT produced in 2007. Atlantic salmon is a carnivorous species that has not been fed high levels of plant feed ingredients in the past. Additional sources of protein to fish meal must be identified that do not decrease growth performance for growth of the salmon industry to continue. A 38-week feeding trial was conducted at the National Cold Water Marine Aquaculture Center (Franklin, ME) with juvenile Atlantic salmon (133 g/f initial weight) to determine the effect of feeding gradient levels of canola protein concentrate. A commercial diet (Signature Salmon 3.5 mm, Northeast Nutrition, Truro, Nova Scotia) was used and modified by the manufacturer to contain 10 or 20% canola protein concentrate, replacing fishmeal and poultry by-product meal. The three diets were formulated to contain 45% protein, and 22% lipid. Diets were prepared and analyzed by the manufacturer. Each experimental diet was randomly assigned to triplicate 0.265 cubic meters containing 20 Atlantic salmon. All tanks were connected to a common particulate filter (rotating screen filter) and biological filter (fluidized sand). Water in the system was brackish water (3 ‰) and obtained from a ground source. Temperature (7.5 to 14°C) and dissolved oxygen were monitored continuously and ammonia, nitrite, nitrate, carbon dioxide, and pH were monitored weekly. Fish fed 20% canola protein concentrate had significantly lower growth compared with the 0% canola protein concentrate diet (p=0.0385). There was not any significant difference in feed efficiency (p=0.2170) or protein efficiency ratio (p=0.2081). Canola protein concentrate significantly depressed growth when included in the diet at 20%.