Protein supplementation for bees [Complete guide]

In a world where climate change and environmental degradation are becoming increasingly evident, bees face unprecedented challenges to their survival. Phenomena such as global warming, unusually warm winters, forest fires and pollution have drastically altered the availability and quality of the essential food for these tireless workers: pollen and nectar. This situation leads us to reconsider how we support our hives, particularly focusing on protein supplementation, a fundamental pillar for the development and strengthening of the bee population.

What do bees need?

Bees require a balanced diet that includes:

• Proteins, mainly from pollen, essential for brood development and royal jelly production.
• Carbohydrates, obtained from nectar and converted into honey, provide the energy required for their activities.
• Lipids, vitamins, minerals and propolis, also derived from pollen and other collected materials, crucial for their immune system and development.
• Water, indispensable for hive life.

Why feed bees with protein?

Protein supplementation becomes a key tool for:

• Increasing colony population, boosting productivity.
• Preparing hives for mass pollination events or intense nectar flows.
• Supporting colony development during periods of scarcity.
• Facilitating recovery after exposure to pesticides or Varroa infestations.
• Ensuring continuous brood production under adverse weather conditions.
• Improving hive stores ahead of winter.

History of protein supplementation for bees

The history of protein supplementation for bees began in 1756 with Samuel Hartlib, who experimented with bean flour on toast, dark beer and sugar, marking the start of the search for the ideal protein food. Over the years, researchers such as Haydak and Herbert in the 1930 and 1980 decades respectively experimented with ingredients such as milk powder, yeast, dried egg, soya flour and casein. These efforts were complemented by De Groot’s research on the ideal amino acid ratio, highlighting the importance of meeting the specific nutritional needs of bees.

An important milestone in this evolution was the work of Dr. Gordon Wardell, whose meticulous research over several years in collaboration with the USDA ARS Carl Hayden Bee Research Center led to the development of MegaBee, the first commercially available protein food designed for global distribution. Wardell accepted the challenge of creating a complete nutritional supplement that was not only effective from a nutritional standpoint, but also attractive to bees. His innovative approach considered the ideal composition and characteristics of a protein food, focusing on crucial aspects such as particle size, avoiding raw materials with potential antinutritional factors such as soya, and selecting ingredients that are palatable. Moreover, Wardell paid special attention to measuring the supplement’s impact on protein levels in the bees’ bodies, ensuring that the final product was not only theoretically superior, but also demonstrated its effectiveness in practice.

Antinutritional factors and their impact

Antinutritional factors are substances present in some foods that may interfere with nutrient absorption or have toxic effects on bees. Soya flour, for example, can be toxic due to trypsin inhibitors that block bees’ ability to process proteins, in addition to containing sugars such as stachyose and raffinose, which have shown toxicity in insects. Egg protein, although rich in nutrients, contains avidin, a glycoprotein that binds to biotin, rendering it ineffective, which negatively affects muscle development and protein synthesis.

Characteristics of the ideal protein food

The ideal protein food for bees must have certain essential characteristics to be effective:

• Small particle size: This increases nutritional absorption.
• Free from antinutritional factors: To avoid negative effects on bee health, such as potential protein blockage caused by soya flour or dried egg.
• High protein content: Fundamental for colony development and maintenance. In cake form, it should exceed 8%, and ideally be 14 – 20% if seeking increased brood production.
• Balanced amino acid profile: Following De Groot’s parameters for correct assimilation.
• Balanced pH: Essential for bee digestive health.
• Versatility: Available in different forms to suit various conditions and needs.
• Palatability: It must have a pleasant flavour, so bees consume it voluntarily.

Bees take in food through the proboscis in much the same way as we drink a slush through a straw. If protein food particles are too large, exceeding 100 microns, they act like pieces of ice in a slush that block the straw, making intake difficult. This phenomenon explains why protein food residues are sometimes found at the bottom of the hive: bees cannot effectively assimilate large particles, preventing proper nutrition.

The Four P’s: Pesticides, Parasites, Pathogens, and Poor Forage

These factors can significantly reduce bee lifespan, affecting their health and productivity. An appropriate protein feeding programme can help mitigate some of these effects, providing bees with the nutrients needed to resist and recover from these threats.

Protein = Longevity

Proteins play a crucial role in bee health and colony development, directly influencing several vital processes. One of the most important functions of proteins is their role in activating the hypopharyngeal glands of nurse bees. These glands are fundamental for royal jelly production, an essential component for healthy larval and queen development.

Royal jelly not only nourishes the queen throughout her life, but also is vital for larvae in their early developmental stages. It is a nutrient-rich substance containing proteins, vitamins, minerals and essential fatty acids, all necessary for optimal development of young bees.

It is well known that a higher protein level in the bees’ bodies correlates with increased longevity. This is a primary objective in beekeeping, as the aim is to maintain strong and healthy colonies for as long as possible. Adult bees, particularly foragers, have a limited capacity to process pollen directly due to their more developed digestive system. Therefore, the only way these bees can obtain the necessary proteins is through trophallaxis, a reciprocal feeding process in which nutrients such as royal jelly are transferred between individuals within the colony.

For trophallaxis to occur effectively and for adult bees to receive sufficient protein, it is essential that there is an excess of royal jelly. This excess is achieved by stimulating nurse bees to produce more royal jelly through protein supplementation. When larvae are immersed in abundant royal jelly, not only is their optimal development ensured, but the nurse bees are also encouraged to share the surplus royal jelly with adult bees and worker bees via trophallaxis. This process not only benefits the larvae but also extends the lifespan of adult bees, increases the colony population, and consequently boosts the number of forager bees.

In addition, a protein-rich diet prevents nurse bees from prematurely shortening their active period in that role. Under normal conditions, a nurse bee becomes a forager once it has completed its life cycle within the hive. However, when the hive is weak and there is a shortage of foragers, nurse bees may be forced to abandon their vital role prematurely in order to compensate for the lack of collectors. This can have negative consequences for the hive, as it reduces the ratio of nurse bees to larvae, affecting the production of royal jelly and the development of the brood. A weak brood pheromone, resulting from underdeveloped brood, may disrupt the balance and overall health of the colony.

A protein-rich diet is essential to stimulate royal jelly production, ensure healthy larval development, extend the lifespan of adult bees, and maintain an appropriate ratio between nurse bees and brood. This in turn strengthens the colony, increases its productivity, and contributes to the overall health of the bee colony.

When is the best time to feed protein cakes to bees?

Protein supplementation for bees is a strategic tool that must be applied with precision and at the right time, always adapting to the specific conditions of each hive, geographical area, and individual situation. Below are some key principles and timing guidelines for effective protein feeding, presented in a clear and practical manner.

1. Strategic Use: Protein supplementation should only be applied when strictly necessary. Not all situations require protein intervention, and its use should be considered as part of a broader nutritional plan.
2. Geographical and Temporal Adaptation: The need for protein supplementation varies according to location and the beekeeping calendar. Each key moment depends on the colony’s life cycle and environmental conditions.

Key Moments for Protein Supplementation

1. Preparation for Wintering: In autumn, prior to the period of winter inactivity, it is essential to strengthen the bees. Supplementation at this time aims to ensure optimal levels of fat and vitellogenin, preparing bees for a healthy and robust winter.
2. Pre-Spring Stimulation: One and a half months before the first flowering, especially in areas with early bloom such as California almond orchards. Early supplementation anticipates the need for a strong, populous colony, ready to maximise the flowering period and ensure efficient pollination.
3. Support for New Nuclei: The formation of new nucleus colonies temporarily reduces the number of available foragers. Providing a protein source close to the brood is crucial to support colony development during this critical phase.
4. Post-Stress Recovery: Periods of high stress for the colony, such as Varroa treatments or intense pollination periods, can weaken bees. Supplementation helps restore their vitality and strength.
5. Pollen Diversity: In situations where the variety of pollen in the field is limited, supplementing the diet with protein cakes can address nutritional deficits and ensure a proper pH balance in the bees’ intestines, using ingredients such as citric acid.

Implementation of Protein Cakes

Protein supplementation must be planned in six-week cycles to cover two brood cycles, administering protein patties every two weeks (approximately 400-500 g per patty, adjusted according to observed consumption).

When analysing the following graphs showing protein levels in adult bees at three and six weeks, it becomes clear that significant differences appear at six weeks. This highlights the importance of completing the full supplementation cycles, avoiding shortening or reducing these periods to ensure a positive impact on bee health.

Protein patties must contain at least 8% protein to be effective, although ideally they should contain 14–20% to unlock the full potential of protein in the colony.

Tips for Successful Feeding Programmes

• Be proactive, not reactive: Anticipate the nutritional needs of bees before problems arise.
• Strategic use of feeding: It is not necessary to feed constantly, but it is important to know when and how to do so effectively.
• Planning: Consider a feeding plan for 6 weeks to cover two brood cycles.
• Location of nutrition: Place feeding sources close to nurse bees to maximise efficiency.
• Feeding efficacy: Dry feeding may be less effective than methods applied directly within the hive.
• Observation: Look for indicators of success beyond the mere disappearance of the feed cake.

Consult our selection of protein feeds for bees and choose the format according to your objective, the time of year, and observed consumption.