NET Protein Utilisation Part 3
How does the body actually absorb and use the proteins, and what is the advantage of a high NPU value?
Proteins split in amino acids. There are enzymes that split the proteins. The enzymes that split the proteins are called Proteases and they form amino acids that travel through the bloodstream to all body cells. This process creates the body’s own proteins. High-quality protein automatically has a higher NPU value. In simple terms, with higher protein utilisation the extraction of all the essential amino acids is higher and this gives a higher yield in nutritional value.
It is often claimed that all the essential amino acids are represented in a particular koi food. In fish meal and/or koi food, the right amino acids to match the body’s own proteins will always be present, only the number and the quality can vary. Hence the advantage of using a high quality protein food with a high NPU value.
Floating Koifood
Making floating pellets is not so easy and so is frequently dismissed as something that is bad for the Koi and not natural for them. They are naturally bottom feeders and only occasionally slurp some natural food from the surface. However, we like to look and observe our the Koi at their best, and so to enable us to do this, floating foods are more suitable than sinking pellets.
It is no mistake that 90% of all the koi food used by breeders in Japan is floating and not sinking. Only when the breeders prepare their Koi for the shows do they use sinking pellets to improve the muscle build of the Koi. We often compare many things with Japan, but all of the splendid koi that we see coming out of the mud ponds of Japan were raised with floating food and not sinking pellets.
Of course some people continue to believe differently, and I would be very interested to hear from them.
Moreover, it is proven that when carp are kept in a clearly increased water flow environment, the feed conversion rate is much higher for the same amount of food. Naturally this results in more weight and more growth from the same amount of food. For those who want to create more flow in their pond, it is important that this increased flow is not put through the filter, but only happens in the pond. It is better to keep the flow of the filter on the recommended rate and the extra flow only in the pond. For that we only need to install extra pumps in the pond and not in the filter.
This will improve the body shape, and give more growth to the Koi without using more food. The reason for this is because the food conversion is much higher and is utilised by the fish in muscle and skeletal growth which equates to quicker growth as opposed to a fish becoming fat and storing excess calories in the belly region.
The process to make the pellet floating is not that simple and there are generally more specialist techniques involved. Let’s talk about this in the next article on koi food and its production.
It is sometimes said that the choice of ingredients with a naturally higher sugar content is less important than I would like, so I would like to pick up on this in the next article and discuss the pros and cons of higher sugar levels in the ingredients of the koi food. Hopefully I will make it clear why a lower sugar content in the ingredients is important.
Production of Koi food.
If you understand what I have written above, you will understand that a lot can go wrong in producing and ensuring a consistent, high quality product. The production process is something that is controlled by the very strictest regulations. This means that the greatest effort is put into safety measures that prevent fungus or other harmful elements that would have a negative impact on the quality of the food. Among other things, contaminated fish meal can be a major problem when not subject to a controlled hygienic process. Also, more people now make their own food, but those doing so need to be aware of the dangers of homemade food and it should be frozen immediately after being made up. To thaw the food, don’t use the microwave. This will reduce the NPU value.
So often Koi enthusiasts profess they do their best for Koi but do you really know what you are putting in to your koi? When you feed your Koi I think you should be entitled to know exactly what is in your food, why it is in there and how it benefits your koi. Next time you are considering a repackaged food from your local Koi dealer maybe you will consider the facts explored in this article.
Jos Aben
Yoshikigoi