A pollen substitute is a valuable resource to maintain bee colonies strong
and healthy, in the absence of pollen in sufficient quantities in nature.
Hence, the current study was performed to investigate the effects of
different levels of dietary proteins and silymarin (SM) as a natural
antioxidant, on honey bee worker colonies. The study was carried out as a
completely randomized design in an experiment conducted using 36 honey bee
colonies in a completely randomized design with nine experimental treatments
(four levels of crude protein 0, 20, 30 and 40%, two levels of silymarin 0
and 0.2 mM and pure pollen (control)), and four replications at Agricultural
Sciences and Natural Resources University of Khuzestan in autumn 2015. In
current study parameters such as workers in sealed broods, newborn workers
bee weight, body protein and, the amount of development of Hypopharyngeal
gland surface were studied. Soybean meal, maize and wheat gluten were
included as pollen substitutes. Based on the results of the pre-experiment,
SM supplement at a dose of two-tenths mM improved the survival of bees.
Capped broods number using the divided box into squares with 2 ? 2 cm,
newborn workers bee weight using the balance, body protein based on the
percentage of body weight and development of the Hypopharyngeal gland
surface using microscopes and micrometers were measured. The results showed
that there was a significant difference between treatments in terms of
laying eggs (P <0.05). The highest and lowest rate of workers in sealed
broods were related to treatment containing 30% protein and SM (12467 cells)
and sucrose treatment (2042 cells), respectively. Also, the highest and
lowest newborn workers bee weight were related to pollen treatment and the
sucrose treatment, respectively (P <0.05). Body protein of worker bees in
studied treatments had significant differences (P <0.05), so that the widest
and narrowest percent body protein were observed in a diet containing 30%
protein and SM and sucrose treatment, respectively. The Hypopharyngeal gland
surface in the colonies fed with different diets was significantly different
(P<0.05) and the widest and narrowest of its surface were observed in the
diet containing 30% protein and SM and sucrose treatment, respectively.
According to the current results, to maximize the reproduction of bees, a
diet containing 30% crude protein is proposed.