Fishmeal, an Advantageous Feed Ingredient

Fishmeal is a beneficial, nutrient-rich ingredient used predominantly as a feed ingredient for domestic animals and occasionally as a high-quality fertilizer. Fishmeal, a marine protein, is a brown powder or cake obtained by cooking, pressing, drying and grinding fish and fish trimmings—including the bones and offal—to remove the majority of the fish oil and water. Fishmeal has been used as a feed ingredient for poultry, pigs, cattle, cows, sheep, camels, horses and other animals for hundreds of years. Fishmeal is also used as an aquaculture feed ingredient. Almost any fish or shellfish in the sea can be made into fishmeal, as long as they are not poisonous or endangered.

The most common process of obtaining fishmeal is cooking, pressing, drying and grinding.

Cooking
Cooking is possibly the most important stage of the fishmeal production process. The fish are cooked in a large cylinder that moves the fish around by a screw conveyor. Undercooking the fish causes the fish to retain its liquor and therefore not be satisfactorily extracted; however, overcooking the fish makes the element too soft to be pressed.

Pressing
The cooked fish is then pressed in a perforated tube over time with increasing intensity. The pressing reduces the oil content to 4% and water content by 20% and the solid material left behind when pressing is finished is called Press Cake.

Drying
Drying is an important stage of the fishmeal creation process. Drying is important because if the fishmeal is under-dried then molds and bacteria develop, ruining the fishmeal; likewise, if the fishmeal is over-dried then scorching can occur, reducing the nutritional value of the fishmeal.

Grinding
Grinding is the last stage of the fishmeal production process and involves the breaking down of lumps or particles of bone so that the meal is uniform, powder-like, and ready to be used in animal feed or fertilizers.