R. Shumkova1*, R. Balkanska2
1Research Center of Stockbreeding and Agriculture – Smolyan, 4700 Smolyan, Bulgaria
2Institute of Animal Science – Kostinbrod, 2232 Kostinbrod, Bulgaria
(Manuscript received 23 June 2020; accepted for publication 3 August 2020)
Abstract. The aim of the present study is to investigate the effect of Baikal EM1 on the productive parameters of the bee colonies (Apis mellifera L.) during spring and autumn feeding and the chemical composition of the worker bee bodies. Two groups of bee colonies were formed (1 experimental group and 1 control group). During the spring feeding the experimental group was fed with Baikal ЕМ1 at a dose of 5 ml/0.500 L added in the sugar syrup (sugar:water 1:1) for 4 consecutive days at the start of the experiment. Each bee colony received 5 L sugar syrup. During the autumn feeding the experimental group received Baikal ЕМ1 at a dose of 20 ml/10 L sugar syrup. Each bee colony received 10 L sugar syrup. The control group received only sugar syrup. The spring and autumn feeding of the group fed with Baikal EM1 significantly increases the strength of the bee colonies and the amount of the sealed worker brood compared to the control group. According to the results obtained for the strength of the bee colonies and the bee brood supplementary feeding with Baikal EM1 is very effective in the autumn feeding. For these two parameters there are significant differences between the experimental and control on 29.08. (p<0.01), 10.09. (p<0.05) and 22.09.2018 (p<0.01). Statistically significant differences were reported for the strength of the bee colonies (p<0.01) and the amount of sealed worker brood (p<0.001) in the experimental group receiving Baikal EM1 before wintering compared to the control group. It can be expected to reveal a tendency for better spring development in the next year. Feeding with Baikal EM1 does not affect the chemical composition of worker bee bodies.