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Trials-2013
Trials-2013
Comparative tests of carbohydrate feeds made from sugar syrup by means of yeast-enzyme agents “PCHELIT”, “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B”. The research was conducted on the production apiaries of State Research Organisation Institute of Beekeeping of Russian Academy of Agriculture in Sochi region in September 2013. INTRODUCTION It is known that honey made from sugar unlike natural honey contains insufficient amount of proteins, minerals and vitamins, which in turn affects the normal life of bees. To eliminate the inadequacy of honey substitutes, there had been made some attempts of their enrichment. In the first half of XX century M. Gaidak added birch pollen extract to sugar syrup in order to make it more similar to honey. G.F.Taranov (1938) and K.A.Aliev (1969) added cow milk to the syrup with the same purpose. A.Rothla (1989) added pollen to the syrup fed in autumn. Thus, despite the fact that feeding sugar syrup to the bees allows us to solve several problems of breeding and keeping the bees, but at the same time, the processing of sugar syrup by bees leads to their wearing, rapid aging and shortening of their lifespan. It is believed that absence of some biologically active substances (naturally found in honey) in sugar syrup and in invert syrup reduces bees’ resistance to the diseases. To solve this problem RPE “TRIS”, Ltd has developed two new feeds for the bees. We tested them at a production apiary near Adler (south of Russia) in September 2013. MATERIALS AND METHODS To carry out the research there were formed 5 groups of bee colonies each consisting of 5 bee colonies. All the colonies were similar in strength, genetics and queen age (all the queens hatched in 2013). The efficiency of the new agents PCHELIT-AKTIV, PCHELIT-COMPLEX-A and PCHELIT-COMPLEX-B was evaluated. There were two control groups: PCHELIT and sugar syrup. Invert syrup was prepared from all “PCHELIT” agents according to the producer’s recommendations. All the groups of bees were fed 1l of syrup every day. Each bee colony has processed 14,9l of syrup. There was no honeyflow during the research. The feeds were evaluated by the following criteria: 1) Colony strength – by counting bee spaces with bees 2) Amount of sealed brood – by counting the number of cells containing sealed brood – counted by means of a gauge frame (each 5x5 cm square equals 100 cells) 3) Amount of honey – by weighing honey frames and then subtracting the frame weight (a new-built comb weighs 400g (including frame weight), a brown comb weighs 600g (including frame weight). The amount of honey in brood frames was estimated visually, considering that a full comb contains 3.6 kg of honey. 4) Number of ambrosia cells – by counting the number of ambrosia cells by means of a gauge frame. 5) Daily oviposition was estimated every 3 days by counting the number of eggs in each colony by means of a gauge frame and dividing the result by 3. 6) Flight activity was estimated by counting bees flying into the hive during 3 minutes (at 10-11 o’clock when the bees are most active) 7) Physiological characteristics estimated:
To evaluate the physiological characteristics we used bees of the same origin, obtained in the donor-colonies. The bees had been marked with a paint and inserted into experimental and control groups of bee colonies. At age 6 days and 20 days the marked bees were caught and put into cages. Half amount of the bees was used to evaluate hypopharyngeal glands and fat body degree of development, other half was used to evaluate the % of water in the bees’ bodies. The latter procedure was carried out by removing the bees’ digestive system and drying the remaining bodies at 105°C until body weight became stable. The hypopharyngeal glands degree of development was evaluated by Hess method (1958). The bees were fixed in Bouin's fluid prior to the tests. The fat body degree of development was evaluated by Maurizio method (1954).
RESULTS It is well known that substitution of honey (intended for feeding the bees) with conventional sugar syrup is followed by a series of undesirable phenomena. The bees who are involved in processing of the syrup are affected in the first place. Using conventional sugar syrup also leads to longer time of water evaporation, saccharose breaking – and as a result – to longer period of fodder honey sealing. Maurizio has pointed out that young bees’ hypopharyngeal glands react to the quality of feed consumed. Our data show that hypopharyngeal glands are affected by feed composition as well as by biologically active substances present in it (table 1). Table 1 Influence of carbohydrate feed composition on bees’ hypopharyngeal glands and fat body degree of development at age of 6 and 20 days (September 2013, Adler, Russia).
It’s clear from the data above that the greatest differences in the development of the hypopharyngeal glands were observed between “sugar” group of colonies and “invert syrup” (“PCHELITs”) group of colonies. These differences ranged from 0.65 to 2.55 points. Significant differences (1.72 points) were observed between “PCHELIT” and “PCHELIT-AKTIV” bee colonies at 20 days of age.
Differences in the development of the hypopharyngeal glands between “PCHELIT-COMPLEX-A” group and “PCHELIT” group were 1 point at 20 days of age. Differences in the development of the hypopharyngeal glands between “PCHELIT-COMPLEX-B” group and “PCHELIT” group were 0.83 points at 20 days of age.
N.A. Ursu (1986) found that during sucrose fermentation the amount of free amino acids and their ratio in the feed changes dramatically. Initially, the amount of free amino acids equals 0.076 mg / g, and then it increases to 0.310 mg / g; the amount of free amino acids in sealed fodder equals 37.782 mg / g. Bees involved in the fermentation of sucrose actively lose protein and age rapidly. Significant differences were observed in the fat body condition. Difference between bees feed on sugar syrup and inverted syrup (PCHELIT) at 20 days of age, was 0.65 points, between “PCHELIT” and “PCHELIT-ACTIV” – 0.76 points, between “PCHELIT” and “PCHELIT-COMPLEX-A” – 0.9 points, between “PCHELIT” and “PCHELIT-COMPLEX-B” – 0.97 points. In experiments that were conducted by H. Novotna (1974) it was also found that bees’ fat body is very sensitive to changes in feed composition. The largest fat cells (68.14 micrometers) were found in bees who consumed honey and ambrosia, the bees fed with honey mixture showed cell size of 42.47 micrometers. The control bees, who consumed sugar syrup, showed cell size of 30.73 micrometers. It is known that reduction of water content in the body of bees in the autumn period is an indicator of their readiness for the winter. Bodies of hardy bees from areas with harsh climate and long winters usually contain less water than bodies of bees from warmer places. On average, the difference in water content between these two groups exceed 4% (M.V. Zherebkin, 1979). As can be seen from the data presented in Table 2, the bees from “PCHELIT-ACTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” groups showed not only lower water content in the body, but also more dry matter content , which means a considerable accumulation of organic substances in the bodies of bees in autumn. Table 2 Influence of carbohydrate feeds composition on % of water in bees’ bodies (September 2013, Adler, Russia).
The greatest difference in dry body mass of worker bees (18%) was between “sugar syrup” and “PCHELIT” groups at age 20 days. Difference between “PCHELIT-COMPLEX-A” and “PCHELIT” groups was also 12%. Differences between “PCHELIT” and “PCHELIT-COMPLEX-B” groups made 13%. Dried bee weight of “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” groups was on average 12.5% more than dry weight of “PCHELIT” group and 30% more than “sugar syrup” group. Flight activity during the honeyflow is known as a kind of honey-gathering characteristic. Flight activity of the bees was evaluated during scarce ivy honeyflow and in its absence due to adverse weather as well.
Fig.1. Flight activity of the bees fed with different feeds (September 2013, Adler, Russia). As seen in Figure 1, the bees flew out of the nest actively in the period from September 17 to September 21. Difference in flight activity between “PCHELIT” group and “PCHELIT-COMPLEX-B” group in this period amounted to 76% on September 17, and to 25% - on September 21. Difference between “PCHELIT” group and “PCHELIT- COMPLEX-A” group amounted to 35% on September 17, and to 12% - on September 21. Differences between “PCHELIT” group and “PCHELIT-AKTIV” group amounted to 30% on September 17, and to 12% on September 21. Bees of “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” groups flew more actively than bees of “sugar syrup” group up to 58% on September 17 and up to 29% on September 21. Difference in flight activity between “sugar syrup” group and “PCHELIT” group was negligible during the period of research. Thus, based on these data, we can recommend the following agents: “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” to get an increase of flight activity of the bees. However, the beekeepers must remember that these agents work most effectively under favorable weather conditions and in the presence of ambrosia in the hives. Differences in oviposition of queens from different experimental groups were also the most significant during favorable weather conditions (Fig. 2). Fig.2. Oviposition of queens from different experimental groups. (09 Sept 2013 – 04 Oct 2013, Adler, Russia). As can be seen from Fig.2, in the period from September 17 to 21, the highest egg-laying was observed in “PCHELIT-COMPLEX-B” group. In comparison with the oviposition of queens from “PCHELIT” group, it was higher by 40% on September 17 and by 60% on September 21. Use of “PCHELIT-AKTIV” has also been effective and allowed to increase oviposition of queens by 40% on September 21 and by 32% on September 17 (compared with “PCHELIT” group). Differences in feed quality had a definite impact on the economic traits of bee colonies (Table 3). Table 3 Influence of different carbohydrate diets on economic traits of bee colonies (September 2013).
As can be seen from the data above, there were no significant differences in the carbohydrate feed stocks (honey) between experimental groups. At the same time, the amount of ambrosia differed among groups. So, in “sugar syrup” group the number of ambrosia cells increased by 700 cells at the end of the experiment (compared to the number at the beginning of the experiment) in “PCHELIT” group it increased by 900 cells, “PCHELIT-AKTIV” – by 1100, “PCHELIT-COMPLEX-A” – by 1100, “PCHELIT-COMPLEX-B” – by 1200 cells. According to our data, the bees consume up to 40% of pollen more when processing sugar syrup compared with inverted syrup (Institute of Beekeeping research - 2008). Despite the high level of oviposition in “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” groups, this has not led to a significant increase in sealed brood (but the amount of sealed brood hasn’t reduced as well). “Sugar syrup” group decreased its amount of sealed brood by 16% at the end of the experiment, “PCHELIT” group decreased it by 9%, “PCHELIT-AKTIV” and “PCHELIT-COMPLEX-A” groups did not happen to reduce the amount of sealed brood and “PCHELIT-COMPLEX-B” group has an increase of 11%. Thus, the use of the following products: “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” can significantly increase the flight activity of bees, the queens’ oviposition; they can also prevent physiological deterioration of bees. The bees fed with these products better prepare for the winter, and in our opinion, these products are excellent for spring stimulation of bee colonies. When preparing the bees for wintering one should use these products earlier (in August). SUMMARY
1. Hypopharyngeal glands degree of development. The greatest differences (20 days of age) were observed between “sugar syrup” group and “PCHELIT-AKTIV” group: 2.55 points in favor of “PCHELIT-AKTIV” group. Significant differences were also observed between “PCHELIT” group and “PCHELIT-AKTIV” group: 1.72 points in favor of “PCHELIT-AKTIV” group. “PCHELIT-COMPLEX-A” group performed 1 point better than “PCHELIT” group, and “PCHELIT-COMPLEX-B” group performed 0.83 points better than “PCHELIT” group. All groups of bees receiving inverted syrup (“PCHELIT”, “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B”) surpassed “sugar syrup” group by 1.72 points on average.
3. Dry body mass of bees. The differences in dry body mass of worker bees were observed between all the groups of bees. “PCHELIT” group surpassed “sugar syrup” group by 18% (age 20 days). Bees of “PCHELIT-AKTIV” group surpassed bees from “PCHELIT” group by 12%. “PCHELIT-COMPLEX-A” group surpassed “PCHELIT” group by 12%. “PCHELIT-COMPLEX-B” surpassed “PCHELIT” group by 13%. Dry body mass of bees from “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” groups was on average 12.5% more than that of bees from “PCHELIT” group and 30% more than that of bees fed with sugar syrup. 4. Flight activity. This criterion is highly dependent on weather conditions. The greatest differences were observed in good weather. Differences in this criterion between “PCHELIT” group and “PCHELIT-COMPLEX-B” group amounted to 76% on September 17, and to 25% on September 21, respectively. Differences between “PCHELIT” group and “PCHELIT-COMPLEX-A” group amounted to 35% on September 17, and to 12% on September 21. Differences between “PCHELIT” group and “PCHELIT-AKTIV” group accounted for 17% on September 30, and for 12% on September 21. Bees from “PCHELIT-AKTIV”, “PCHELIT-COMPLEX-A” and “PCHELIT-COMPLEX-B” groups flew more actively than those from “sugar syrup” group on average by 58% on September 17 and by 29% on September 21. Differences between “sugar syrup” group and “PCHELIT” group were negligible during the test period. 5. Queens’ oviposition. Differences in oviposition of queens from different groups were also the most significant in the period of favorable weather conditions. The highest oviposition was observed in “PCHELIT-COMPLEX-B” group. In comparison with “PCHELIT” group it was higher by 40% on September 17 and by 60% on September 21. Using “PCHELIT-AKTIV” has also been effective and allowed us to increase oviposition of queens by 40% on September 21 and by 32% on September 17 (compared with “PCHELIT” group). 6. Number of cells with ambrosia. At the end of the experiment “sugar syrup” group increased the number of ambrosia cells by 700 (compared with the number of ambrosia cells at the beginning of the experiment); “PCHELIT” group increased it by 900 cells, “PCHELIT-AKTIV” – by 1100, “PCHELIT-COMPLEX-A” – by 1100, “PCHELIT-COMPLEX-B” – by 1200 cells.
CONCLUSION We recommend using “PCHELIT”, “PCHELIT-AKTIV” and “PCHELIT-COMPLEX-B” to make invert sugar for feeding bees in different periods of the year. “PCHELIT”. Apply from August to October. Application starts after the end of the main honeyflow. “PCHELIT” is used in autumn to make winter feed stocks, the degree of sugar inversion being less than 60% in order to avoid crystallization of feed in the cells during winter. “PCHELIT-COMPLEX-B”. Apply in spring (March – May/June), starting from the first cleansing flight, in order to increase strength of the colony after wintering. Especially beneficial for weak colonies.
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