Feed Quality - Part 2

Most beekeepers in the Atlantic region are currently feeding their bees in preparation for a successful winter.  Last week we started to discuss some considerations around the quality of the feed we provide our bees.  Feed quality is directly linked to bee longevity and therefore overwintering survival.  Let's explore this further in this weeks blog.

Feed Quality - Part 2

There is a body of research indicating that poor quality feed negatively impacts honey bee health and longevity^3,4,5. The repeated conclusion of researchers is that the best quality feed for bees is honey⁶, second is sucrose syrup.  The implications for overwintering success are clear, poor-quality feed will increase winter mortality!  It may be intuitive to think that direct and clear signs of poor-quality feed, such as dysentery and the bees reluctance to consume, are important.  Bees may consume degraded feed at the same, or perhaps an even faster, rate as good syrup⁷.  Dysentery can be caused by a number of things and should not be relied on as a determination of feed quality.  The more subtle indicator of poor-quality feed may be increased winter losses as a result of changes in pH and increased hydroxymethylfurfural (HMF).  The increase in HMF in sugar syrup is used as a direct marker of quality deterioration⁸.   The levels of this toxin will build over time, increase with temperature and in the presence of acid.  The final catalyst for HMF formation, acid, is worth discussing further.

Honey contains approximately 75% simple sugars such as fructose and glucose⁹ with only a relatively small proportion of sucrose (a more complex sugar). The simple sugars are a nutritionally available energy source for the bees and the sucrose will be broken down further.  This reduction of the complex sugars by the bees, called inversion, is achieved using an enzyme (invertase).  This enzymatic inversion of more complex, disaccharide sugar (sucrose) to monosaccharide sugars (fructose and glucose) is part of the natural process of making honey from nectar.  Inversion of sucrose can also be achieved artificially by using acid instead of the enzyme invertase.  These two different processes are referred to as enzyme hydrolysis or acid hydrolysis.  The later process will result in HMF as a by-product of inversion.

Feeding sucrose syrup with a in frame feeder.

The increase in HMF in sugar syrup due to the addition of acid is something that beekeepers should understand.  Outdated practices to include acid as an additive for feed are thought to extend shelf life and convert sucrose to simpler sugars.  Although this will be a catalyst for inversion, this is no longer recommended due to the resulting increase in HMF.  It is also worth noting that recipes for homemade fondant generally include some form of acid (citric acid, acetic acid).  The acid along with heating of the sugar syrup inverts the sucrose into simple sugars.  The acid and the heating will both increase HMF levels.  Good quality commercially available fondants will use enzymatic hydrolysis.  If you read the marketing information on Hive Alive® fondant, as an example, it states “produced using enzymatic hydrolysis without the use of acids or heat processing, thereby avoiding the introduction of harmful HMF”.

When using and storing sugar syrup there are some things that beekeepers should consider.  Store your syrup in airtight, sealed containers with as little ‘headspace’ as possible.  Low temperature storage will slow down degradation, which is almost arrested at 4˚C but increases greatly above 20˚C.  Also, heavy syrup (67% sucrose) will keep longer. There are currently no preservatives which have proven to effectively extend the life of sugar syrup and are also safe for bees. The use of any acid-based additives or preservatives can be harmful.  So understanding that the indicators of poor quality (e.g. MHF, changes in pH) increase with storage time, monitoring and testing of syrup is advised.

A couple of final points!  If taking risks with sugar syrup, dilute any questionable feed as much as possible with fresh.  Fall is the time bees are most at risk from tainted feed.  Ensure that your syrup and feed have low toxicity (i.e HMF) and understand the link between age, storage temperature, pH and toxification.  Feeding the freshest and highest quality syrup available will always be best practice.

References

3. Frizzera, D., Del Fabbro, S., Ortis, G., Zanni, V., Bortolomeazzi, R., Nazzi, F. and Annoscia, D., 2020. Possible side effects of sugar supplementary nutrition on honey bee health. Apidologie, 51, pp.594-608.

4. El-Seedi, H.R., Ahmed, H.R., El-Wahed, A.A.A., Saeed, A., Algethami, A.F., Attia, N.F., Guo, Z., Musharraf, S.G., Khatib, A., Alsharif, S.M. and Naggar, Y.A., 2022. Bee stressors from an immunological perspective and strategies to improve bee health. Veterinary Sciences, 9(5), p.199.

5. EFSA Panel on Contaminants in the Food Chain (CONTAM), Schrenk, D., Bignami, M., Bodin, L., Chipman, J.K., del Mazo, J., Grasl‐Kraupp, B., Hogstrand, C., Hoogenboom, L., Leblanc, J.C. and Stefano Nebbia, C., 2022. Evaluation of the risks for animal health related to the presence of hydroxymethylfurfural (HMF) in feed for honey bees. EFSA Journal, 20(4), p.e07227.

6. Quinlan, G., Döke, M.A., Ortiz-Alvarado, Y., Rodriguez-Gomez, N., Koru, Y.B. and Underwood, R., 2023. Carbohydrate nutrition associated with health of overwintering honey bees. Journal of Insect Science, 23(6), p.16.

7. Polinsky, M., 2024. Personal Communication, Aug 29.

8. Solayman, M., Shapla, U.M. and Khalil, I., 2023. Furfural and Hydroxymethylfurfural. Honey: Composition and Health Benefits, pp.152-166.) .  This compound is toxic to bees and shortens their lives. 

9. da Silva, P.M., Gauche, C., Gonzaga, L.V., Costa, A.C.O. and Fett, R., 2016. Honey: Chemical composition, stability and authenticity. Food chemistry, 196, pp.309-323.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

Feed Quality - Part 1

The domestication of honey bees has directly resulted from their ability to produce abundant provisions to maintain the colony through periods of dearth.  A colony will store honey in quantity to survive for times of little or no nectar flow.  This excess honey has for millennia been a prized food source for us!  As our harvesting of honey could leave the bees starving during the winter, we have a responsibility to replace what we have taken.  This is, for the most part, done through the feeding of sugar syrup back to the bees.  So as beekeepers, we want to provide the best feed possible to our bees.  There are some considerations to ensure the quality of syrup and feed which will be discussed in this, and next, week’s blog.

Feed Quality - Part 1

Fall feeding of bees should be done with heavy (67% sucrose) syrup.  The syrup should be the highest quality and most fresh available.  Sucrose, the white granulated sugar that is found in most kitchens, is preferred and what most beekeepers in the Atlantic region use.  Other sugars such as high fructose corn syrup (HFCS) can be fed to honey bees if it is high quality but nutritionally, sucrose is better for honey bees.

For most beekeepers there are two options for sugar syrup.  Granulated sucrose can be dissolved in water for homemade sugar syrup or premixed sugar syrup can be purchased.  Both options have considerations when it comes to quality.  Homemade syrup is fine as long as it is made carefully.  The saturation point for sugar in solution is 67% sucrose at room temperature (20˚C).  If the temperature of the solution is increased, dissolving the sugar is easier but excessive temperature can create compounds which are toxic to bees.  So, care must be taken to avoid overheating the solution.  Boiling of syrup must be avoided!   If purchasing premixed sugar solution, it should be fresh and checked for any indication of degradation.  

Filling a frame feeder with sucrose syrup (ATTTA 2024)

There are simple ways for beekeepers to check the quality of sugar syrup.  Sugar syrup should be clear with very little colour.  As feed ages other compounds form from the sucrose “browning” which occurs.  This colour change is due initially to the formation of hydroxymethylfurfural (HMF)¹.  This is a compound toxic to bees and linked to mortality².  Fresh, high quality sugar syrup should have no unpleasant smells.  Any off smell could indicate fermentation or other degradation.  Sugar syrup should not be frothy or produce any gasses.  This is also an indication that the syrup is degrading.  

There are other tests which can be conducted to determine the quality of sugar syrup.  If the basic assessments mentioned above throw up any red flags, this is a very good option for beekeepers.  The acidity of the feed, as indicated by pH, is a very good quality measure.  Fresh sugar syrup should have a pH around 6.0 to 7.0. For context, milk is about 6.5 and pure distilled water is completely neutral at 7.0.  As the sucrose breaks down, acids are formed and these lower the pH.  Some of these acids are toxic to bees and will reduce their longevity³.  Another important test of sugar syrup is titratable acidity which measures the total acidity of the solution.  This is different from pH and is an indication of how difficult it is for the bees to utilize this feed.  When the bees consume syrup which has high total acidity, they are required to buffer it in their gut for digestion.  So titratable acidy shows how hard the bee’s gut need to work to buffer against the acidity present.  It is also worth noting that two syrups with the same pH may have different titratable acidity.  Another measure of syrup is Brix (˚Bx) which is, in this context, a measure of the amount of sugar in the solution.  Sugar syrup for fall feeding should be 2 parts sucrose to 1 part water by weight.  This would mean that there are 67 grams of sugar for every 100 mls of solution with a ˚Bx of 67.   These lab-based tests can be arranged by sending a sample to ATTTA.

Next week we will continue to discuss feed quality!

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

References

1. Quintas, M.A., Brandao, T.R. and Silva, C.L., 2007. Modelling colour changes during the caramelisation  reaction. Journal of Food engineering, 83(4), pp.483-491

2.  Zirbes, L., Nguyen, B.K., de Graaf, D.C., De Meulenaer, B., Reybroeck, W., Haubruge, E. and Saegerman,     C., 2013. Hydroxymethylfurfural: a possible emergent cause of honey bee mortality?. Journal of Agricultural and Food Chemistry, 61(49), pp.11865-11870.

3. Frizzera, D., Del Fabbro, S., Ortis, G., Zanni, V., Bortolomeazzi, R., Nazzi, F. and Annoscia, D., 2020.                 Possible side effects of sugar supplementary nutrition on honey bee health. Apidologie, 51, pp.594-608.

Last week’s blog gave some insight into feeding pollen patties to our bees in the spring.  If you want to read one of our previous blogs on this topic, have a look at Blog #54 called Pollen Patties: To Feed or not to Feed?  There is also information in our fact sheets found on our ATTTA website.  This week we will continue the conversation about spring feeding.

Spring Feeding Sugar Syrup to Honey Bees

Early spring is a precarious time for honey bee survival, perhaps even more so than winter.  This is the time in the beekeeping season when many colonies can be lost to starvation.  In addition to feeding pollen patties, as discussed last week, sugar syrup can also be provided to support bees until environmental food resources are available.  Let’s explore some key points in deciding whether or not spring feeding of sugar syrup is necessary and how this can be achieved.

A common statement made by experienced beekeepers is that spring feeding is done in the fall!  What this means is that, under normal circumstances, a honey bee colony that has been well prepared for winter and fed correctly in the fall will be provided with enough stores to survive until the spring floral bloom.  In the Atlantic region the first flowering plants to provide nectar for honey bees are from the aster family.  Coltsfoot (Tussilago farfara) is generally the first of this family to flower in April.  But the first significant source of nectar for honey bees comes from the Common Dandelion (Taxacacum officinale).  Dandelion bloom is the signal for beekeepers that the season has begun and after this point sufficient resources will be provided by abundant natural nectar sources.

The first step in the decision whether to feed sugar syrup in the spring is to assess the colonies themselves.  A simple way this can be achieved is with the “heft” test.  Experienced beekeepers will determine the remaining stores of honey in the hive by lifting the hive slightly to feel the weight.  If a hive is sufficiently heavy (>25 kg in early spring) then no feeding is required. A light hive will require feeding.

Figure 1. A beekeeper feeding sugar syrup in the spring to a colony via a frame feeder.  Most frame feeders will have a wooden top with vertical ladders access by the bees through holes.

If feeding is deemed necessary, then a solution made from granulated sugar (glucose) is recommended. This spring solution is typically one part sugar to one part water by weight.  This concentration of sugar is theorized to more closely resemble the sugar content of spring nectar.  This concentration may entice the bees, by mimicking favorable spring nectar flow, to increase brood production and improve spring build up.  Many beekeepers make up their own solutions of sugar syrup but premixed bulk syrup is also an option.

There are several choices available to beekeepers to deliver feed to bees.  A range of the most common feeders are seen in the pictures.  Frame feeders can be a convenient method of feeding bees, especially if they have remained in the hives since the previous fall.  If this is your practice, remember to remove and clean the feeders annually as they can become a habitat which will support certain pests of honey bees. These style feeders also allow the bees to access the feed without leaving the hive.

Figure 2. A pail feeder (left) and a top feeder (right).  Both good options for feeding bees sugar syrup.

A pail feeder can be placed on top of your colonies and will deliver feed directly to the bees below.  This method is preferred by some beekeepers as the location of the pail, like the frame feeder, allows the bees direct access to the feed.  This method also can be applied by the beekeeper without having to enter the hive.  Most often placed over the opening of a wooden inner cover and is best used in conjunction with an additional empty super surrounding the feeder with the outer cover then placed on top of the whole structure.  As another option, the top feeder acts in a similar way to allow bees access to the feed through the inner cover.  This is a good method for ease of access, once in place, and a large quantity of feed can be made available to the bees.

There are other methods of feeding sugar syrup and beekeepers are advised to find what works best for you and your operation.  One thing to remember when spring feeding is that pollen patties and sugar syrup will stimulate your bees into growth mode.  If we are artificially inducing spring build up then we must support this additional growth until natural resources are available.  So once started, careful monitoring of your bees will be required, along with possibly continued supplemental feeding.  So, assess individual colonies, in consideration of operational demands (i.e. pollination), and provide feed as appropriate.  Once bees are progressing along a spring growth trajectory, make sure they have the nutritional resources to maintain it.  Many beekeepers keep healthy bees without any spring feeding of sugar syrup!  So, the choice will be based on your experience, seasonal variation in weather, and the performance required from your colonies.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

 

How Much do We Need to Feed?

Last week we discussed different styles of equipment which can be used to feed supplementary sugar syrup to honey bees. This week, we will continue the discussion of fall feeding, considering the nutritional requirements for the bees and how much syrup will be necessary to achieve these requirements.

Also, see information below on our latest ATTTA podcast.

How Much do We Need to Feed?

Beekeepers typically need to feed bees in the fall to replace the honey harvested from the hive. In Atlantic Canada, it is recommended to overwinter hives with at least 35kg of honey stored. With these reserves, strong hives should be able to withstand the winter. A common way to measure the honey content in a hive is by lifting the hive to assess its weight. If you are able to lift the hive with one hand, it is likely that the hive is too light and requires feeding. With experience beekeepers become very good at assessing hive weight with this “heft” test.

Supplementary feeding may be required at various times throughout the beekeeping season and is done for different reasons. For example, a new colony which does not yet have drawn comb will need to be fed to stimulate wax production. In the fall, feeding is typically for the purpose of stocking food for the winter. For this, a ratio of 2:1 sugar to water is the ideal syrup. Thick syrup is useful for fall feeding because it creates less work for the bees. When forager bees collect nectar and bring back it to the hive, it is then cured within the hive for proper storage. Nectar typically starts with about 70% water content and is stored as honey with about 18% water. Water is removed first through the act of passing the nectar from mouth to mouth within the colony and then further by fanning bees and warm air circulating through the hive. Removing excess water creates a substance with a higher sugar concentration, allowing bees to store more energy efficient reserves in less space and creating a substance that is not capable of spoiling! Supplementary sugar syrup needs the same treatment. By providing bees thicker syrup to begin with, they are more easily able to cure the syrup into a storable form.

 

How much syrup must you feed your bees? This question depends on how much honey is already in the hive and how much stored food you would like your bees to have. One gallon of 2:1 sugar syrup will be converted into about 3.2 kgs of stored food. Therefore, if you want your bees to store an additional 35 kgs on top of what is already in the hive, you must feed them 11 gallons (41 liters) of 2:1 feed.  It is very unlikely that a normal, healthy hive would contain no honey. Be mindful of excessive feeding, as well. It is possible to overfeed your bees and be left with a honey bound hive. In this case, the queen may run out of space to lay and the population of bees in the spring will be unfavorably low. The bees will also need time to cure the syrup into its storable form. If they are not allowed sufficient time to cure the syrup, it may enter the winter with excessive water content and end up freezing or fermenting, both of which are detrimental to overwintering bees. Here in Atlantic Canada, September is a good time to start with supplemental feeding and normally by mid October feeding should be complete.

For even more information on feeding your bees and getting them ready for the winter, check out the ATTTA Fall Honey Bee Management Guide (https://www.perennia.ca/wp-content/uploads/2019/10/09-fall-honey-bee-management-guide-eng.pdf) and Feeding Honey Bees (https://www.perennia.ca/wp-content/uploads/2018/04/06-feeding-honeybees-eng.pdf) fact sheets.

 

What’s the Buzz with ATTTA Beekeeping Podcast 

Episode 8

The Canadian Honey Council (CHC) represents all beekeepers from the hobbyist with one hive through to the largest commercial operation with thousands of colonies.  Nationally, there are more than 10 000 beekeepers, managing nearly one million colonies, supported directly by the work of the CHC.  As the national association of the beekeeping industry, the CHC undertakes many of the big issues related to honey fraud, product labelling, employment and much more.  This month’s episode of What’s the Buzz with ATTTA Beekeeping podcast explores the work of the CHC through a discussion with the association’s executive director, Rod Scarlett. You can find the podcast HERE.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

 

Feeder Styles

Fall is fast upon us in Atlantic Canada, which means that it is time for fall beekeeping! Good management in the fall is essential for coming out of the winter with strong hives able to proliferate in the early spring. One important practice for overwintering strong colonies is to be sure they are properly full of stored honey- or stored sugar syrup! In this blog, we will provide an overview of various options for feeding your bees syrup this fall.

Feeder Styles

Six common ways that beekeepers feed their hives are through pail feeders, hive top feeders, division board feeders, empty drawn comb, Boardman feeders, and plastic bags. 

Pail feeders. Pail feeders are typically 1 gallon plastic buckets or 5-10 lb. glass jars. The tops are modified to have small holes which allow bees to access the syrup within when the container is inverted over the hive. These feeders can be home made or commercially purchased. To make your own out of a glass jar, a nail can be used to pierce about 5 holes, each approximately 1.5mm in diameter. For a plastic pail, it is recommended to create a single hole in the center of the lid about 1 inch in diameter and then cover the hole with a fine metal screen. Fill the container with syrup and then invert it over the inner cover. Once the initial dripping has stopped, place the container over the hole of the inner cover and add an empty super to surround the feeder, protecting it from the elements. Lastly, remember to place a weight on the top of the outer cover to secure the super in place. 

Hive top feeders. Hive top feeders are typically the size of a shallow super and are placed directly on top of the hive, under the inner cover. They are filled with syrup but have an entranceway which is isolated from the liquid. Through this entrance, bees can enter the feeder from the hive below and crawl over and down the walls to access the surrounding sugar syrup.

Figure 1. Hive top feeder. Image to the left shows the entrance through which the bees can access feed. Image to the right shows the protective cover in place, which floats on the surface of the syrup.

Division board feeders. These are also called frame feeders, as they assume the place of a frame within the hive, typically placed against a wall. Division board feeders are plastic containers with a floatation device, such as Styrofoam or wood, which float on top of the syrup within and allow the bees to drink without drowning. It is also common for these feeders to be fashioned with ladders or roughened inner walls to help the bees crawl down into them. Unfortunately, drowning is still quite common with division board feeders.

Figure 2. Division board feeder next to a nuc box. 

Empty drawn comb. A frame of empty drawn comb can be used as an in-hive feeder, as well. It is recommended to fill the frame by slowly submerging it into a container of syrup to properly fill the comb. This is does not provide a large volume of food but can be useful for emergency feeding as the frame can be placed directly next to the brood nest. Comb which has previously been subject to brood disease should not be used for this purpose.

Boardman feeder. Boardman feeders are not highly recommended for feeding sugar syrup. A Boardman feeder is a stand which holds an inverted quart-sized mason jar. The base of the stand is inserted into the front of the hive, through the entrance, for bees to crawl into and gain access to the liquid inside the mason jar. The placement of the jar at the entrance of the hive makes it quite vulnerable to the elements and troublesome mammals. Cold weather can freeze the syrup and hot weather can cause fermentation or added medications to become altered. Rather than feeding, the Boardman feeder is most recommended for providing water in times of drought. A quart of water during drought will go much farther than a quart of syrup. 

Plastic bag feeders. The same plastic bags that we use to hold our food can also be used to hold food for bees! Half-gallon plastic Ziplock bags can be filled about ½ - ¾ with syrup, sealed tight, and laid flat on the lid of the inner cover or top bars. Cut a 1-2 inch slit on the upper side of the laid bag and the bees will slowly access the syrup inside. 

In next week’s blog, we will continue the discussion of feeding sugar syrup with a blog about the nutritional implications of feeding bees.  

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca