| Trace elements play an important role in animal growth and production performance.Some data indicate that the growth and reproduction of bees require the participation of trace element cobalt.Cobalt also has the effect of improving the antioxida nt capacity of the bees and enhancing immunity.In order to further explore the effects of cobalt on the growth and physiology of bees,this experiment intends to use the Italian honeybee(Apis mel ifera L)as a research object to carry out indoor larval feeding experiments by adding different levels of cobalt to the bee larvae and adult worker bees.And the out-of-group adult worker bee feeding test,measuring and observing the growth and development,lifespan,physiological and biochemical indexes of the bees and related gene expression,in order to find out the nutritio na l effects and mechanism of cobalt on bees.Test 1: The effect of cobalt on the growth and development of Italian bee larvae.1200 1-day-old(1 d)Italian bee worker bee larvae were removed from the sister bee colony and divided into 5 groups with 10 replicates per component and 24 larvae per replicate.One group was the control group and the basal diet was fed;the other four groups were the experimental group,and different levels of cobalt were added to the basal diet at the levels of 0.06 ?g/g,0.13 ?g/g,and 0.26 ?g/g,respectively.,0.39 ?g / g.The 1 day old worker bee larvae were placed in an indoor constant temperature and humidity incubator,and the temperature of the wet incubator was set to 30 ° C,the humidity was 50% to 60%,and the feed was changed daily before the pupation,and raised to the feathering room.Larval samples were collected for 5 d,6 d,and 7 d,and the physiological and biochemical indexes and related gene expression levels were determined.The phlegm rate and emergence rate of each group were counted.According to the statistical analysis,the results showed that:(1)Compared with the control group,the larval larvae had a significantly higher phlegm rate(P<0.05)when the cobalt addition level was 0.06 ?g/g.(2)When the cobalt addition level was 0.06?g/g,the total protein and glucose in the hemolymph of bee larvae increased significantly(P<0.05).(3)When the level of cobalt in the larvae feed increases(0.06?g/g~0.26?g/g),the antioxidant enzymes(SOD,CAT),arginase(Arg)and phosphatase of the bee larvae of the bee larvae The activity was significantly improved(P < 0.05).(4)With the increase of cobalt addition level in bee diet(0.06?g/g~0.26?g/g),the expression levels of superoxide dismutase(SOD)and catalase(CAT)genes also increased.High(P<0.05);compared with the control group,the arginase(Arg)and phosphatase gene expression levels increased significantly when the amount of cobalt added in the larvae diet was 0.06?g/g~0.13?g/g.(P<0.05).Test 2: Effect of cobalt on the physiological function of adult worker bees.From the Italian bee sister bee colony,2500 young bees(1d)that had just emerged from the house were selected and divided into 5 groups.Each component was 10 replicates,and each replicate had 50,of which 1 was the control group.The sugar solution was fed;the other 4 groups were experimental groups,and different levels of cobalt were added to the sugar solution,and the addition levels were 0.6 ?g/g,1.3 ?g/g,2.6 ?g/g,and 3.9 ?g/g,respectively.Put each group of bees into a special bee feeding device(patent number: ZL 2014 2 0503643.3),put each feeding device 50 bees were placed in a constant temperature and humidity incubator.The temperature of the incubator was set at 30 ° C and the humidity was 50% to 60%.3 mL of sugar solutio n with different cobalt levels was fed with a syringe every day to observe the performance of the bees and remove the dead bee body.Feed until the end of the experiment.The samples were collected from 7d,14 d and 21 d,and the physiological and biochemical indexes and related gene expression levels were determined.The lifespan of the bees was determined by 5 replicates in each group.The results showed that:(1)Adding cobalt to the adult worker bee feed is beneficia l to prolong The life span of worker bees and the cobalt addition level of 0.6 ?g/g were significantly higher than those of the other groups(P<0.05).(2)Cobalt had an effect on the cobalt deposition of bee body tissues.As the amount of cobalt added in the diet increased,the cobalt content in the bee tissue increased continuously,and the difference between the groups was significant(P<0.05).(3)Total antioxidant activity(T-AOC),superoxide dismutase(SOD),arginase(Arg),phosphoric acid of the bee body when 0.6?g/g and 1.3?g/g were added to the diet.The phosphatase activity was significantly increased(P < 0.05).(4)With the increase of cobalt addition level(0.6?g/g~2.6?g/g)in bee diet,the expression levels of catalase and superoxide dismutase genes also increased(P<0.05).Compared with the control group,the amount of arginase and phosphatase gene expression increased significantly when the amount of cobalt added in the feed was 0.6?g/g~1.3?g/g(P<0.05).This study shows that the level of cobalt in the diet affects the growth and physiology of the bees.When the addition level of cobalt in the bee larvae feed is 0.21?g/g,it can promote the growth and development of larvae.When the level of cobalt in adult bee diet is 2.00 ?g/g,it can improve the life span,antioxidant capacity and immunity of bees.Ability and other physiological functions. |
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