Koi Nutrition

Posted by Chris Jubb on

Koi Nutrition Koi Nutrition explained[/caption] Koi Nutrition explained.  It never ceases to amaze me that we spend a lot of money on our pond, filter systems, treatments, latest gadgets etc yet seek out the cheapest food we can, whilst expecting high quality. Or, we really do not understand the importance of correct nutrition. I will attempt to shed some factual light on the subject and hopefully give you a better understanding of why you need to feed the correct balance of nutrition to your prized collection. Firstly, it is imperative to realise that deficiency and imbalances in nutrition can lead to detrimental effects on your koi, such as poor skin quality, fin clarity, slime coat, poor colour, inhibited growth and reduced immunity. However, we must also understand that there are other factors too, which include genetics, oxygen levels, heat and water quality. Most keepers seem obsessed with growth, and rapid growth. It is worth noting that steady, managed growth by way of good water, oxygen and nutrition is much better as it will give a more prolonged period of peak colour, good skin quality and general health, rather than growing fast and big! If your koi does not have Jumbo genetics, it will NEVER be a Jumbo koi regardless of how much you feed it. This will yield fat koi with internal issues, such as fatty deposits around the heart and kidneys, simple. When the nutrition of a koi is balanced you will see consistent growth all around the body. Out of balance we will see a fat belly, lethargic swimming and poor health. Most quality koi pellets have a high energy to protein ratio, which is what you should be after. Foods over 45% protein content will promote protein deposit build up in the liver and kidneys ( not good), but too little protein (less than about 30%) will lead to slowed growth and amino acid imbalances which will lead to long term issues for the koi. Don’t get too hung up on protein content, look at the overall balance of the food and your koi’s requirements. If you are really obsessed with feeding your koi high protein, then let me know and I will send you a bag of my toe nail clippings, which are packed full of protein. Koi do not digest protein easily, but find those derived from an aquatic source, such as fish meal, a lot easier. Animal protein should not be considered. The protein content is broken down and releases free amino acids that are then absorbed through the digestive tract and distributed by the blood to the various internal organs. If the food contains the incorrect amino acid profile then the koi will suffer, as it needs these for growth and cell regeneration and less will be used for this as they will be used to maintain functions more important. So always use a high quality food with a white fish meal protein source, as this is more easily digested and contains exactly the right amino acid profile. Soya can also be considered as this is just 1% less digestible than fish meal and does contain the ten essential amino acids. This is why wheatgerm is such a good all year round food, as it contains the same amino acid profile when broken down as white fish meal. Do not use foods that state” Fish or Fish Derivatives” or cereal based foods. And quite often manufacturers list Fish Meal as the first ingredient, but it is invariably brown fish meal, which is basically the mush from bones, tails eyes etc. You can get a clue as to the quality of fish meal by having a look at the Ash content. A higher ash content can indicate that a better quality fish meal has been used. Ash is misunderstood, do not assume it is all waste and the koi will poo it out, because it is not. It is, basically, the result of burning the protein source at 350C and what is left is the ash content… minerals such as potassium, zinc, magnesium etc etc , which the koi CAN utilise. For an adult koi a protein intake of 35-38% is sufficient, whilst due to their much faster metabolism, young tosai ( up to a year old) will quite happily take up to 65% and burn it up quickly. It is important to know what the protein has been derived from, as a crude protein content listed on the bag only tells you the amount, which in fact could be a usable amount of 15% on a bag listing 40%. It is all about the correct amino acid profile. So a bag with 30% protein listed could be better quality and a more balanced food than one with 45% protein! Fats in the diet are often overlooked, but are vitally important, as apart from serving a protein sparing effect, they are the basic fuel in fish metabolism. Fats are stored in the body for buoyancy and for energy reserves. Certain fats ( lipids) are essential for cellular structure maintenance and development. You should be looking for a fat content of around 7-9% and it will typically come from fish oils, such as salmon. Fats also drive the growth and a content of up to 14% can be found in some foods, which is a little bit excessive for Nisai and older. Along with Carbohydrates ( which is never actually listed % on a bag of food), lipids, or fats, are really needed for quick energy bursts, as the koi cannot get enough energy quickly from a protein, it needs to be stored in the white muscle tissue. It is important to build up the carbohydrate intake coming into winter, as this will give the koi more reserves to draw on throughout that period. However, many brands of food contain too much carbohydrate, which is not ideal. Pearl Barley is ideal, boiled up accordingly. Most pellets now have adequate vitamin and mineral content, but always check that the Vitamin C is stabilised. Unstabilised Vit C will simply dissolve into the water as soon as the pellet hits, so pretty worthless. And Vit C is vitally important to maintain a healthy immune system, this is why soaking the pellets in orange juice is considered good practice. Also look for high levels of Vitamin A & E. One of the most common reasons people feed a particular food is “ because my koi love it”. Now, with respect, that is rubbish. They are omnivores and will eat anything, but just like us they get used to a pellet and any change confuses them. And don’t get hung up on this “ less waste” malarkey. Firstly, your koi will poo. You have a filter to take care of that waste. The amount of poo really doesn’t matter and is not necessarily an accurate indication as to how good or bad the food really is. Faeces has very little to do with the amount of ammonia produced in your pond. Whereas we excrete most of our nitrogenous waste as faeces, koi do not, as they are ammonetelic, producing most through their gills. And the darker the pellet, the darker the poo will be. A lighter pellet will produce lighter poo, tricking you into thinking there is more waste, simply because it is more noticeable on the pond base! There are so many foods on the market nowadays, many with attractive sounding Japanese names, but please ensure that you are feeding your koi the very best you can afford. It doesn’t have to be the most expensive, there are a few mid range foods that are well balanced and made from good ingredients. Using fresh food is also important. I do not use 15kg bags as once they are opened the contents will degenerate, especially the vitamin content. Throwing loads of food in is also bad practice, as some vitamins in the pellet are water soluble, leading to certain vitamin deficiences over time. Dampening the pellets will help the koi feed quicker and thus give complete benefit of the food. Remember, just because a food lists a high protein content does not mean it is getting that amount of protein, you have to trust the brand. The first ingredient listed on the bag should be Fish Meal ( or wheatgerm if applicable). Soya is also acceptable. Colour enhancing foods should be fed sparingly, I am not a fan of colour food at all. Koi will get the carotenoids they require from grazing on the algae in the pond. Too much spirulina or astaxanthin will bring out genetic weaknesses and cause stray hi on the white ground, but the most common effect is creamy whites, caused by waste build up. Shrimps contain high levels of carotenoids and I have seen many fish ruined because of overfeeding shrimps. These are what make flamingos pink, after all! I often get asked “ I have a pond of koi varying in age from tosai up to yonsai, so what do I feed?”. The answer is…. Feed the tosai. The first year of the koi’s life is critical and lays down the building blocks for its future. Ruin it as tosai and chances are you’ve ruined it for life. Many quality tosai are ruined because the owner has forced the growth and fed a poor diet. A koi has no choice what to eat, it has to make do with what you chuck into the pond, so please ensure that you are chucking a well balanced food in!!

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