The protein requirements for honey bees (part two)

The protein requirements for honey bees (part two)

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This post is also available in: Spanish

Before we continue with presenting the principles of selecting the appropriate protein supplements, we have to mention once again that the optimal protein source for honey bees is and always will be pollen. No other supplement can successfully replace pollen all together, it can however only complement it to a great degree of success. Like in the case of sugar syrup being used when there isn’t sufficient nectar flow, there are situations when pollen availability is very scarce and we must intervene with additional protein sources. It is a known fact that pollen is difficult to store for later use and obtaining quality pollen from a third party source is again risky (pollen is a sure way to transmit diseases if there are any). And finally, not all types of pollen can provide all the nutrients that honey bees require in order to sustain brood rearing and to form their fat bodies.

Taking into consideration the above mentioned facts, as well as the information from part one, it is clear that a protein supplement is absolutely necessary in order to complement pollen during certain periods. Otherwise there is the constant risk of the colony entering a state of nutritional stress with very serious consequences, varying from early capping of the larvae, the loss of the fat body and shortening of the life span of the bees.

In many situations, not having a basic knowledge of the bee’s protein requirements led to the use of inefficient and even harmful supplements. As an example, the use of soy flour instead of soy protein isolate or milk powder instead of whey protein isolate can have a major negative impact on the bee’s digestive system. It is then mandatory to have a solid grasp on the bee’s nutritional needs. And we can only achieve this by studying their natural protein source, the pollen. We will further talk about three major aspects.

The first one is the protein percentage in pollen. It is a well known fact that this number depends upon the origin of the pollen, so we will refer to average values. These vary from 16% (in studies made in Spain) up to 30% in other areas of the world. It was established that pollen of high quality must have at least 25% protein, while pollen with 20-25% protein is considered to be satisfying. Below 20% protein pollen is considered to be of poor nutritional value. An important note must be made here: even though the quantity of protein is the most important, if it comes from pollen of low quality it leads to a premature wear of the bees, shortening their life span. The protein percentage is therefore equally important.

The second aspect is the key to a more profound understanding of the matter. After analyzing 27 different types of pollen from 3 countries, there were identified 17 amino acids, 10 of them being essential amino acids. These amino acids are present in the same ratios, even though the type of pollen is different. In other words, even though every type of pollen has different amounts of these amino acids, their ratio in that particular type of pollen are constant. Later studies have shown that if these ratios aren’t optimal, the bees simply cannot use the total amount of protein. As an example, a change of ratio between isoleucin and valine (normally 4:4) to 3:4 led to only using 75% of the total amount of a protein supplement. These findings explain why some protein patties formulas are far less efficient than pollen. Most of them don’t take into account the ratio of the amino acids. We can use this information for conceiving a protein patty/supplement that resembles natural pollen to a very high degree.

The third important finding is with regards to the micro nutrient composition of pollen (vitamins and minerals). Vitamins from the B Complex were present in large quantities; as for the minerals, 13 elements were present in significant amounts, while another 14 elements were found only in trace amounts. Even though there aren’t many relevant studies at this moment, a known fact is that the amount of ash must be between 0.5 and 1%. This is in spite that the natural pollen can contain between 2 and 4% ash. It was found that pollen with more than 2% ash leads to the reduction of brood rearing, while supplementing with protein containing ash in excess of 8% led to a complete stop of the brood rearing. The amount of ash is in direct correlation to the amount of minerals, so a high amount of minerals in supplements can cause more harm than good. We should definitely take this into account before adding vitamins and minerals to pollen substitutes without a strict control over the quantities.

The three above mentioned aspects are extremely important in understanding the nutrition of the honey bee. Going into more details requires a vast amount of information that cannot be covered in a single article. The nutrition, alongside the right queen bee, regular health checks of the colonies (regularly replacing the combs, treatments etc.) and a decent management is one of the big four pillars of beekeeping success.
Photo: Flickr

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