Effect of supplementary diets on the performance of honeybees (apis mellifera) during dearth period in Baringo County

Abstract

The dry periods in arid and semi-arid lands in Kenya (ASALs) affect honeybees due to a shortage of pollen and nectar, jeopardizing colony health, honeybee industry viability, ecosystem balance, human nutrition, and income for the ASAL communities. To address this challenge, a study was conducted in April, 2023 to July, 2023 at the Dryland Research Training and Ecotourism Centre (DRTEC) in Chemeron, Baringo County. The aim was to investigate the effect of supplementary diets on honeybee performance. There were four dietary treatments: T1 (control), no supplementary feed; T2, soybean flour, T3, chickpea flour, and T4, ground Prosopis juliflora pods. All diets included milled sorghum, brewer's yeast, skimmed milk, and honey as additional supplements at varying ratios. Twelve wooden Langstroth beehives with similar colony strengths were randomly selected and labelled for the experiment. Proximate analysis of the diets was done before the feeding trial which was conducted. Each hive received 250g of their assigned dietary supplement weekly for thirteen consecutive weeks using the top bar feeding technique. The data that was collected involved population density, honey yield, sealed brood area (cm³), and diet acceptance. During the thirteen-week period, the amount of the population density and sealed brood area was measured on a weekly, bi-weekly, and monthly basis, respectively. Honey was harvested at the end of the research. Regarding the results, the feed intake of the diets T2 (soybean) at 105.18g +2.53g/week and T3 (chickpea) at 106.57g +2.50g/week were not significantly different. Both diets had significantly higher intake than T4 (Prosopis pods) with an average intake of 78.13g ± 2.53g per week. Colonies fed on diets T2 (soybean) and T3 (chickpea) had the largest sealed brood areas (1720.00cm²±86.69cm² and 1586.75cm²±60.58cm², respectively) compared to T4 (Prosopis pod meal) with 1101.88cm²±52.41cm². The control group (T1) had the lowest sealed brood area at 908.38 cm²±32.25cm². The highest bee population density (8 frames/colony) was observed in colonies fed T2 and T3 diets. Diet T4 followed in population density while the control group (T1) exhibited the lowest population density (5 frames/colony). Honey production had similar trends to density. Colonies in the control group (T1) yielded 3.53kg±0.46kg, while those fed T2, T3, and T4 yielded 9.50kg±0.68kg, 8.13kg±0.58kg, and 5.37kg±0.35kg, respectively. Colonies fed soybean and chickpea (T2 and T3) supplements made significantly more honey as compared to the other treatments. The result of the study showed that soybean and chickpea flour supplements enhanced the performance of honeybees, resulting in higher honey yield and higher income.