The use of fish oil in fish feed is both expensive and unstable. With the increasing concern over the future availability of fish oil, soybean oil has been studied as an alternative.
The study involved six daily feedings to 23 day old juvenile Pacific bluefin tuna of one of four diets with different fish oil and soybean oil ratio's. The study analysed the affect of the diets on growth performance and fatty acid composition.
The results highlighted that there was little difference in growth when comparing the two diets.
There was also little difference seen in body weight gain, feed consumption or feed efficiency.
The diet with soybean instead of fish oil also saw a whole body crude lipids content and lipid retention efficiency increase.
As a result of the little differences between the diets, Mr Biswas stated that soybean oil was seen to be a suitable replacement for fish oil.
He also stated that 10 - 20 per cent of fish oil can be replaced by soybean oil, helping to reduce costs.