|
The following article is from one of the segments of the Koi Health Advisor training. It is written about koi, but applies to all fish.
Why Fresh Food is So Important
(Excerpted from Nutrition by Chris Neaves)
The freshness of the food you feed your fish is very important for their health, growth and well-being. Age will degenerate even the most heavily preserved food. Old food will have lost much of its nutritional value.
Unless manufactured dates or sell by dates are printed on packets it is very difficult to know exactly how fresh or when the food was manufactured.
Some large fish food companies would manufacture large amounts of food to reduce costs. This is then stored and exported.
Koi food that is old loses its effectiveness. Vitamins degenerate rapidly in koi foods (within months). Vitamins that have degenerated are no longer present in the required quantities. Without sufficient vitamins proteins do not function to their full potential. Oils will become rancid with contact with the oxygen in the atmosphere. Without oil levels, energy is not provided and the balance in the formulation will be lost.
The formulation or balance of the ingredients of the food is calculated so that the protein, vitamins, minerals, etc. will be at the required level after cooking and extrusion (the processing method).
However, the cooking process increases the digestibility but destroys a portion of the vitamins and minerals present in the actual food ingredients. Adding a vitamin and mineral pre-mix to increase their levels before extrusion, compensates for this.
The vitamins are extremely vulnerable to degeneration, one of the first being vitamin C. A few years ago vitamin C would start degenerating within weeks of manufacture. Now heat stable, long lasting vitamin C is added to koi food.
Oil, so necessary for energy and proper utilization of the protein content, will go rancid after time. Many anti-oxidants are used in koi food to delay these processes, but it can never be stopped.
Any additional moisture will activate any of the ingredients in the food with the disastrous production of toxic substances. Therefore, food that is more than 9 months old should be viewed with great suspicion – no matter the claims of the selling agents. When in doubt – throw out! Food older than 9 months should be thrown away.
Koi food should be stored in cool, dark and dry places. Sunlight, moisture and oxygen will speed up the process of degeneration of the ingredients. The longer a packet of food is exposed to the atmosphere the less the nutritional value. Many vitamins, the lipids (oils) as well as the protein become unstable when exposed to oxygen.
After opening a large packet of koi food it is suggested that you repack the bulk of it into smaller bags and seal them to keep the food fresh. If necessary, store food in a fridge. Having a plastic bin or container that can seal is a good idea and will help to keep the food fresh. Food stored cold must be brought up to room temperature before the container is opened. If it is not, water will condense on the food creating a potential spoilage problem.
Koi food should never be stored where it may become damp. This includes the concrete floor of the garage. Moisture in sufficient quantities will seep through the concrete floor to dampen the koi food. Therefore, ensure the food has been stored an inch or two off the floor.
Any food that has become damp for a period of time should be discarded. Rancid food can have a long-term effect on the health of koi. Disease problems may only occur many months or years after feeding rancid food. Food that appears to have mildew or fungus on it has become damp at some stage and should be discarded. When storing feed avoid humidity and dampness. Always close and seal the packets or containers after feeding.
Remember – When in doubt – throw out! It is cheaper to discard a few pounds of food than to replace a fish collection.
|
|
