جستجوی مقالات مرتبط با کلیدواژه « ظرفیت آنتی اکسیدانی » در نشریات گروه « محیط زیست »

Heat stress in honey bees causes a decrease in queen egg laying and the life span of workers on royal jelly production cells. In order to reduce the effects of heat stress and increase the body resistance of bees, heat stress problems can be minimized by providing antioxidant substances. The current research aimed to determine the effect of different doses of vitamin C on queen egg laying, antioxidant status and body weight of nurse bees, larval acceptance percentage, and royal jelly production. A total of 30 honey bee colonies (Mellifera meda) were equalized and organized for royal jelly production in July and used in a completely random design. Colonies were fed vitamin C in concentrations of zero, 1000, 1500, 2000, 2500, and 3000 mg/liter for 30 days. The body's antioxidant capacity, weight and composition of the body of nurse bees, the percentage of larval acceptance, and the amount of royal jelly produced in each cup were determined. The lowest body weight of nurse bees belonged to colonies that received 2500 and 3000 mg of vitamin C per liter of syrup. The lowest antioxidant capacity of the body was observed in the control group, and the highest mean was in the group receiving 3000 mg of vitamin C per liter of syrup. The control group had the lowest egg-laying area, and the colonies receiving 2000 mg of vitamin C per liter of syrup had the highest egg-laying area of the queen. The highest percentage of larvae acceptance was observed in the group receiving 2500 mg of vitamin C per liter of syrup. The lowest percentage of larva acceptance was observed in the control group. The lowest amount of royal jelly produced belonged to the control group, and the groups receiving 2000 and 2500 mg of vitamin C per liter of syrup had the highest amount of royal jelly per cell. Colonies receiving 2500 and 3000 mg of vitamin C per liter of syrup were highly aggressive. The results of the present study showed that supplementation of 2000 mg vitamin C per liter of syrup increases larval acceptance and royal jelly production and improves queen egg laying. By supplementation of vitamin C, the aggressive behavior of worker bees increases, which leads to increases in the risk of the bees' stings

It sees that with using water cress plant (Nasturtium afficinale) in an integrated fish and plant culture system, it would be possible to initiate an equilibrium ecosystem for culture of Rain bow trout fry. With running an experimental design, effect of different densities of water cress on fry (Oncorynhcus mykiss) and antioxidant capacity of water were evaluated in a water recirculating system. The treatments were different levels of Water cress; 0, 20, 40 and 60g plant separately introduced in each hydroponic chamber of experimental unit in triplicates.  The survival of fish in treatment with 60g plant was significantly (p < 0.05) lower than other treatments and from 20 pieces reached to 15±1.24  pieces at the end of experiment.  With feeding on the fish, the EC of water increased in all treatments without any significant differences (P>0.05). The highest and lowest EC of water recorded in treatments with 0 and 20 g plant with the rate of 594±60.51 and 580±82.31μs/m, respectively. Antioxidant capacity of water in treatments with 40 and 60 g plant reached to 414.75±15.90 and 414.75± 5.90 μm/l, respectively at the end of experiment. It was concluded that there is not any balancing between amounts of introduced plant and fish into the culture system, and nominated plant needed more concentration of nutrients for growth. The results of this experiment opened new vision of research to standard the water-born condition for growth of fish based on antioxidant capacity of water.

In order to evaluate the effects of Essential® (a commercial mix of herbal essential oils containing Ricinoleic acid, Cardanol and Cardol) on milk production and composition and blood parameters, 20 Holstein dairy cows (DIM=80±20) were used in two experimental groups in completely randomized design. Experimental groups included: 1- control group (total mixed ration and no additive) and 2- Essential® group (supplementation of 13.5 gr Essential®/cow/day in the TMR) during 30 days of experimental period (consisted of 21 days adaptation followed by 9 days sampling period). The TMR consisted of 41.6% alfalfa hay, 2.83% cotton seed and 55.57% concentrate (Dry Matter bassis). There were no significant differences between experimental groups in milk production and compositions and 4% fat-corrected milk (P>0.05). Also, substantial differences were not observed between experimental groups in glucose, triglyceride, urea, albumin, total protein, LDL, HDL and hepatic enzymes (P>0.05). Essential® consumption led to higher cholesterol concentration and total antioxidant capacity than control group (P