Rice bran (RB) is commonly used for aquaculture feed formulation nowadays. It is a main ingredient for both industrial feed (30 – 40%) & home cooked feed (60 – 70%). The available & abundant source of RB in Mekong Delta significantly contributes to the cheaper cost for fish/animal feed production cost. However, a problem occurred in using RB to formulate fish feed is that normal unstabilized RB containing high level of fat (especially unsaturated fat) which affects fish metabolism; hence lower down the immune system that causes high mortality rate. Oxidized Lipids in RB limits the storage shelf life & quickly deteriorates quality of RB.

How does rancid RB affect fish?

RB by nature is very unstable in terms of quality. Un-stabilized rice bran’s quality continuous deteriorates after the milling process and turns rancid quickly. As per the research findings from Fishery College of Can Tho University, dried RB of 1-month-storage is not suitable for fish feed. Normally, fish farmers buy normal RB so called fresh; but in fact, it is oxidized and often contains higher level of impurities such as husk, wood ash, and sand. A noticeable issue is that when the rancidity can be smelled, rancid RB totally exceeds the permission for fish feed making. Science researches have proved the following effects of rancid RB to feed quality:

·         Feed with rancid smell affects eating ability & feed effectiveness.

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·         Toxics are produced.

Conventionally, rancid rice bran is used as direct or indirect fish feed. When fish eat the feed produced from the rancid rice bran, toxics are accumulated in the fish’s liver, which badly affects the immune system of fish & causes the following symptoms:

·         Hemorrhage, swollen stomach & liver 

·         Eat less & high feed conversion ratio

·         High mortality rate

·         Slow growth rate

Therefore, fish fillet quality will be affected due to accumulation of fat. All this are unseen costs to the fish farmers. A rough calculation of this annual loss is USD 15 million if there is only 5% mortality rate of 300,000 tons Tra fish in 2004.

Calofic Cam Vang – optimum solution for fish farmers

With strict requirements of the world market towards foodstuff hygiene, fish material for processing has to be fresh & clean. If fishes eat rancid RB, they easily catch diseases; hence, resulted in high anti-biotic deposition as farmers use many kinds of medicine for treatment.

As a real fact, in developed countries such as U.S.A. & Australia, stabilized RB has popularly been used in replaced of normal RB due to its preeminent features. Their racehorses have been feeding on stabilized RB long ago because of high nutrition content. Oil extraction process takes out most of unsaturated fat in RB, main factor of oxidation process. Regarding the nutritional aspect, well-known domestic & international scientists (Dr. Houde Han, Prof. Charles F. Shoemaker) have proved the domination of stabilized RB as compared to normal RB. In order to meet the demand of good feed for clean fish material, Cai Lan Oils & Fats Industries Co.,Ltd. Can Tho branch (Calofic Can Tho), a pioneer in Vietnam, has invested a factory equipped with modern technology from German to produce a kind of stabilized RB trademarked Calofic Cam Vang - enriched protein RB to supply to Vietnamese fishery industry. As per research findings from Fishery College of Can Tho University, the differences between Calofic Cam Vang & dried RB are as follows:

Especially, Calofic Cam Vang has longer storage shelf-life, high nutrition contributing to fast growth rate of fish, less fat, high fillet yield. Therefore, it could bring long-term benefits to fish farmers. Calofic Cam Vang contributes to the “green revolution” of Vietnam’s aquaculture industry. To enhance the Vietnamese fish export value and competitiveness in the world market, should the fish farmers have to carefully choose the good materials for fish feed?