虻蛆采食不同碳氮比食料的营养物质与能量转化特征

Conversion performance of nutrients and energy by black soldier fly larvae (Hermetiaillucens L.) for feeding the artificial diets with different initial C/N ratios

碳、氮是影响虻蛆生长的两大重要营养素。为确定虻蛆高效转化中适宜的初始碳氮配比,本文采用不同初始碳氮比(10、15、20、25、30)的人工食料,研究虻蛆转化前后各营养物质和能量转化指标的变化特征。结果显示:食料在10与30碳氮比下虻蛆生物量生成效率最高,但两者之间差别不显著(P> 0.05),其相对初始增重倍数、日增重倍数及虫料比分别为43.5%与41.7%、5.1%与4.9%、23.1%与21.2%。在30碳氮比下食料减量率最大(62.3%)、虫粪生产速率最小(99.5mg/g·d),虻蛆转化食料减量效果最好;粗蛋白质、无氮浸出物、总能量、易利用能的总损失最小,总损失率分别为5.9%、74.5%、23.8%、40.4%;粗脂肪在虫体中大量累积,总量增加最多,增加量是初始值的11.4倍;粗纤维则在虫粪中大量累积,总量增加18.8%,与碳氮比10、15差别不显著(P> 0.05);粗灰分及磷元素无代谢损失。虻蛆利用的营养成分和能量主要是脂肪、无氮浸出物、蛋白质及其代表的易利用能,其在食料中的减量率随碳氮比增大呈下降趋势。虫体中粗脂肪、粗蛋白质的累积率随碳氮比增大而增大,虫体中无氮浸出物、粗纤维、粗灰分、总磷的累积率受食料碳氮比影响小。虻蛆转化不同食料后,虫体富集粗脂肪、粗蛋白质、粗灰分、总能、易利用能,虫粪富集粗纤维、粗灰分、磷,其含量分别是食料的7.75~55.58、1.37~2.84、1.03~1.61、1.51~1.68、1.43~1.57、2.08~3.39、1.33~1.94、1.53~1.89。综合考虑虻蛆生物量生成与食料减量效果及营养物质能量转化效率,虻蛆生物转化食料调配的最佳碳氮比值为30。该研究结果为虻蛆高效处理有机废弃物提供工艺参数依据。

Carbon and nitrogen are two important nutrients that affect the growth of black soldier fly larvae.In this study,different artificial diets of initial C/N ratios(10,15,20,25,30)were prepared to investigate the conversion characteristics of nutrient and energy,and to determine the optimal C/N ratio for more efficient organic waste treatment by black soldier fly larvae bioconversion.The results showed that when the initial C/N ratios were 10 and 30,larvae biomass formation were most efficiency with no significant difference(P>0.05),the relative to initial weight gain,daily weight gain and larvae feed ratio respectively were 43.5%and 41.7%,5.1%and 4.9%,23.1%and 21.2%.When the C/N ratio was 30,diets reduction were best for the diets loss rate was most(62.3%)and larvae vermicompost formation rate was least(99.5 mg/g·d).In addition,the total losses of crude protein(CP),nitrogen-free extract(NFE),gross energy(GE)and easy-to-use energy(EUE)were the smallest,the total loss rates were 5.9%,74.5%,23.8%,40.4%in turn;crude fat(EE)accumulated in the larvae body,the total amount increased the most,the increase was 11.4 times of the initial value;the crude fiber(CF)accumulated in larvae vermicompost,the total amount increased by 18.8%,which was not significantly different from that of C/N ratio 10,15(P>0.05).There was no biological metabolic loss of crude ash(CA)and phosphorus(TP).Nutrients and energy absorbed by black soldier fly larvae mainly were EE,NFE,CP and their representative EUE.Those reduction rates of artificial diet decreased with the increase of C/N ratio,changing ranges were 46.58%~91.42%,75.58%~89.07%,63.81%~73.84%,73.17%~86.54%,respectively.The accumulation rate of EE and CP in larvae body increased with the increase of C/N ratio,and that of NFE,CF,CA and TP were less affected by the C/N ratio.After different artificial diets conversion by black soldier fly larvae,EE,CP,CA,GE,EUE in larvae body and CF,CA,TP in larvae vermicompost all were enriched,with their enrichment coefficients of 7.75~55.58,1.37~2.84,1.03~1.61,1.51~1.68,1.43~1.57,2.08~3.39,1.33~1.94 and 1.53~1.89,respectively.Considering the biomass formation,diets reduction,nutrient and energy conversion efficiency,the artificial diets of initial C/N ratio was 30,which could be used as the suitable proportion for black soldier fly larvae bioconversion.The research results provided the basic technological parameters for the efficient organic waste treatment by black soldier fly larvae bioconversion.