Koi Nutrition 101

Koi Nutrition 101

What to look for in koi food

When you’re purchasing koi food, size matters. Look for pellets that are keyed to the size of your koi. Young koi (4 inches or less) need a pellet small enough to eat right away, so they don’t have to wait for it to fall apart. Look for pellets about one-eighth inch across for small koi. Quarter-inch pellets are fine for adult koi. When you’re sure you’re looking at the right size of food, you still have some choices to make, and it’s easy to get confused.


Caring for Koi and Keeping Them Healthy

Basically, you want to pay attention to the variety of ingredients and to the levels of vitamins, minerals, protein, and fat. To narrow down your choices, read the contents list on the container to ensure that these important nutrients are at appropriate levels (as described later in this chapter), and that the food draws its ingredients
from varying sources.

Some details to note about koi food products:
 The list can include vitamins and items as common as ground corn and as arcane as rose hips. Specifics as to the actual value of each may be lacking, but experience has shown that such foods are good for koi and readily accepted by them.

 Some ingredients can meet more than one nutritional guideline. (For instance, wheat germ can provide vitamins, protein, and carbohydrates, and oils can provide energy and vitamins.) Koi nutrition is not an exact science, so don’t worry about ingredients that seem to overlap. Reputable companies use formulas that have, over time, been shown to provide koi with fairly complete nutrition.

Koi are pretty simple creatures, so you don’t need to buy 18 kinds of koi food and still wonder about the nutritional value. You just need to stick with diets that meet the guidelines set out here and add a few of the extra items that we will discuss in the following pages.

The following sections lay out the essentials for your koi’s diet.

Protein
Protein is one of the most important contents because fish need it for energy, growth, and tissue repair. The best sources of protein in a koi diet are fish meal and soybeans. Animal protein (from chicken for example) is not as
digestible. Fish sources may include whitefish meal, anchovy meal, herring meal, and shrimp meal. The protein content may be 25 to 36 percent of your koi’s diet, depending on the season and the age of your koi. Consider the following information as a guide:

 During the summer: Protein should be 30 to 36 percent of the diet when the energy needs of your koi are higher (during the active summer months).

 During the winter: Protein should be nearer 25 percent of the diet when koi are less active and their metabolism slows (in the fall and early winter).

 When they’re young (under 3 years of age): Protein should be 30 to 36 percent of the diet. Look for a food that lists protein first on the ingredients label. (All manufacturers list contents from highest to lowest according to their dry-weight quantity.)

If you prefer to stay on the middle ground and not veer into high or low protein levels, buy plant-derived protein sources, like wheat germ pellets. These sources generally provide enough protein (and they’re a good source of vitamin E). You can give these to your koi throughout the year, but they are especially important during the cooler seasons.

Carbohydrates
Carbohydrates are another energy source. They’re also good sources of fiber and a main component of vegetables and fruit.

If koi don’t have carbs for easy-to-obtain energy, your koi break down protein instead, which leads to a vastly increased output of ammonia. However, you need to strike the right balance because too many carbs can lead to chubby koi. The correct amount is not firmly established, but 60 to 70 percent is safe. Suitable sources for
carbs are plant-based foods such as wheat, corn, soybeans, and rose hips.

Lipids
Oils and fats (or simply lipids) are another source of energy and a good source of fat-soluble vitamins like A, D, E, and K. Koi derive lipids from animal-based foods such as fish meal and shrimp meal, as well as from fish oil and wheat germ oil. An ideal koi diet consists of 3 to 10 percent fat. The high end is for fast-growing young fish, and the low end is for adult fish. The fat content of the diet should come from easily digested sources, such as wheat germ, during the colder months when the fish’s metabolisms are operating at a reduced pace.

Vitamins and minerals
Vitamins and minerals are important components of a koi diet (as they are for any living organism). Little is known of the exact levels required by koi, but those included in long-established commercial foods can be trusted.

Fiber
Fiber is the vehicle that carries the food components through the digestive system where they are then absorbed. The longer the food’s in the gut (within limits, of course), the more time the fish has to absorb the nutrients. This is obviously the advantage to fiber in the diet. However, the less fiber, the less bulk in the excreted feces, which is important when you’re raising koi in fairly high numbers because less bulk means less strain on your filtration system. In practice, however, your best option is not to attempt to regulate feces composition via diet. Rather, feed a standard commercial diet and use adequate filtration for the number of koi you have. If you feel you must reduce the volume of the feces that your fish produce, use a lower-fiber food, such as wheat germ pellets, as the main portion of their diet.

Good sources of fiber are ground corn, oats, wheat germ, and similar plant-based foods. The fiber provided by these generally makes up about 5 percent of commercial diets, which seems to be an adequate level. Fiber content should, like other foods, be reduced in the cooler months. Recommended winter foods such as wheat
germ pellets have a fiber content of 2 to 3 percent.

Courtesy: Koi for Dummies- Koi Nurition 101