Study On The Optimization Of Feeding Condition And Selenium-rich Technology Of Black Soldier Fly

Black soldier fly belonging to Saprophagous,has been extensively studied due to their feeding on dung and other decaying organic matter and its conversion to the characteristics of body protein and fat.Dry matter content of black soldier fly larvae is 42%-43%,in which crude protein content accounted for 42%-44%,fat content 31%~35%,so black soldier fly larvae can be as the protein feed addition and body fat can prepare biodiesel.Selenium is the necessary trace element for human,Keshan disease,Kashin Beck disease,white muscle disease are associated with selenium deficiency myopathy.Compared with inorganic selenium,organic selenium toxicity is weaker,and used easily.In this paper,we use black soldier fly to transfer inorganic selenium into organic selenium,and expect to find a new way of selenium-rich insect.In this paper,we feed the larvae with soybean meal and wheat bran,studying the influence of the feed ratio,feeding temperature,feed moisture and stocking density to the black soldier fly larvae growth.Finally,the optimal conditions for feeding are obtained by calculating: soybean meal and wheat bran weight ratio is 1:1;the rearing temperature is 30 degrees;feed initial moisture content is 75%;the larval rearing density is 150 /200 g dry feed.Under this condition the average larval weight is 4.98g/20;survival rate is 94.67%;feed consumption is 47.01%;feed conversion rate is 11.33%.Compared with non optimized,it is greatly improved.We use sodium selenite as selenium source to study the selenium rich ability of larvae.The results showed that,compared with the control group,the treatment of 5mg/kg containing selenium can increase the weight,survival rate,feed consumption,feed conversion rate and total selenium content,but there is no significant difference between the two groups.With Selenium content increasing,due to the inhibition of selenium,larvae weight,survival rate,feed consumption and feed conversion rate decrease,and the decrease was positively correlated with the concentration of selenium.The total selenium content in larvae increased with increasing selenium content in feed,and 40mg/kg treated larvae total selenium content was 31.33mg/kg.With the increase of the concentration of inorganic selenium in feed,the proportion of organic selenium in the larvae gradually decreased.We investigated the influence of selenium on the growth and development of the three continuous generation black soldier fly and results showed that high concentrations of selenium significantly reduced larval weight and pupation rate,pupa weight and survival rate,eclosion rate and adult longevity;selenium stress the longer the greater the magnitude of decline;high concentration of selenium extended the development time of the larvae and pupae significantly,and selenium stress the longer development needs more time;low concentration of selenium reduced fecundity with the increase of stress time,but high concentrations of selenium increased fecundity slightly with the increase of stress time;The selenium content of larvae was increased with the selenium stress time increasing,but the organic selenium in the body is gradually reduced.Therefore,adding high concentrations of selenium in feed of black soldier fly can affect three generations of growth and development.