Effect of Bee Bread on Pregnancy Outcomes and Reproductive System of Rats under Heat Stress Exposure

Exposure to extreme temperature during pregnancy was associated with abnormal birth outcomes including preterm birth, low birth weight, and placental abortion. Bee bread is a natural product created by bees that is highly nutritional and was recommended for human consumption as a source of high energy and protein. Hence, this study aims to determine the effect of bee bread on pregnancy outcomes and the reproductive organs (i.e. ovary and uterus) of the Sprague Dawley rats exposed to heat stress. Pregnant Sprague Dawley rats were divided into four treatment groups (Control (C: standard feeding); Treatment 1 (T1: Bee bread); Treatment 2 (T2: Heat stress) and Treatment 3 (T3: Bee bread + Heat stress)). Rats from T1 and T3 groups received bee bread (0.5 g/kg body weight/day) orally using oral gavage starting from day-0 of pregnancy until delivery, while rats from T2 and T3 groups were exposed to 43 degrees C of heat by using an egg incubator for 45 min/day until delivery. After delivery, pregnancy outcomes were assessed and the dams were euthanised. Reproductive organs were dissected and weighed. Rats in the T2 group had significantly (p<0.05) decreased litter size and foetal birth weight as well as an increased percentage of resorption and increased gestation period when compared with C and T1 groups. T3 group had shown improvement as positive effects of bee bread during heat stress exposure on litter size, foetal birth weight and percentage of resorption. It can be concluded that bee bread supplementation has beneficial effects on the adverse effects of pregnancy in rats subject to heat stress.