Black Soldier Fly Larvae | An Earth Friendly Feedstock?by Terry Green on 01/28/13
When it comes down to sustainability and the environment, Black Soldier flies (BSF, H. illucens) in their larval stage voraciously consume organic wastes, assimilating nutrients in the waste directly into insect biomass. In doing so they divert organic byproducts and greenhouse gases from ending up in the atmosphere and waterways. The larvae, themselves, are also of significant nutritional value. Birds, salamanders, frogs, many reptiles, other small mammals in the wild, domesticated swine and chicken, and even fish benefit nutritionally in dining on them. As more people learn how to grow BSF in large quantities, and begin marketing the larvae as commercial feedstock, BSF larvae may even one day reduce overfishing of the oceans.
How can this be so? The answer lies in the nutritional makeup and high nutritional value of BSF larvae in animal feeding trials relative to that of two well-known high quality commodity feedstocks, soybean meal and Menhaden fish meal. There is a fairly long history going back to the early 1970's of good results achieved in early feeding trials using BSF feedstock in supplementing the diet of chickens, fish and swine. BSF larvae have already been tested in more advanced studies in feedstock formulations presented to trout and catfish demonstrating that they can support the growth of a high quality product in good yield. Chickens avidly consume BSF larvae even without formulating them into feedstock (Fig. 1).
To better understand the nutritional aspects of BSF relative to that of soybean and Menhaden fish meal, consider the nutritional makeup of each. Dried soybean consists of about 35 - 40% high quality protein, 15 - 20% lipid, 30 - 35% carbohydrate and ~5% mineral ash (chemical composition of the seed). It is highly prized as a feedstock because of its protein and lipid content and the ease with which it can be formulated into a variety of feedstock formulations. It is in demand in feedstock formulations used for human consumption in such products as soy milk, tofu, tempeh, etc. On the other hand, Menhaden fish has a protein content of ~65 %, ~10% lipid and ~20% mineral ash content. It is used in commercial feedstock formulations in raising poultry, swine, cattle and fish. BSF larvae on a dry weight basis contains ~40 – 45% high quality protein which is equivalent nutrtitionally to that of soy meal protein, ~30% lipid and ~15% mineral ash. Dried larvae are especially rich in calcium and phosphate. The Ca:P ratio of dried BSF larvae is typically in the range of 1.5:1, and greater (depending upon the source of organic waste on which they were fed), which is highly desirable in achieving good dietary absorption of calcium and phosphate.
Ironically, the increased worldwide demand for Menhaden fish meal has led to overfishing and depletion of Atlantic and Gulf coast Menhaden fish reserves which is obviously detrimental to the health of the ocean ecosystem in supporting other fish dependent upon Menhaden fish for their own survival. Menhaden fish meal sold on the US commodity market in 1977 for around $300 ton has now at the end of 2012 reached market levels in excess of $2000 per ton (Fishmeal Monthly Price - US Dollars per Metric Ton), driving up sharply the costs of animal feedstocks including that incurred by commercial poultry and fish farmers. The rising commodity prices of Menhaden fish meal are driving up the cost of producing food worldwide. Worse yet, it is a significant factor driving up the rate of overfishing of ocean waters.
Given the high nutritional quality of BSF larvae as a feedstock relative to that of Menhaden fish meal, it is reasonable to anticipate that BSF larvae, produced in large enough quantities to meet the demand presently filled by Menhaden fish meal, could ease the pressure on overfishing oceans off the US and Gulf coasts. To have such an effect, it will be necessary to find ways to produce BSF at levels on an industrial scale to ensure a steady supply of BSF feedstock aimed at offsetting the demand for Menhaden fish meal.
From a sustainable, earth friendly perspective, what could be a better goal than to dispose of our food scrap and agricultural wastes using BSF to assimilate the nutrient value of the waste, to lessen pollution of our atmosphere and waterways as they incorporate nutrients into insect biomass, and in turn to use the harvested larvae in animal feedstock formulations, reducing in the process the pressure on overfishing our oceans? Think of it as spinning gold from garbage, a sort of modern day allegory of the old Rumpelstiltskin fairytale!
Comments on this blog, or any of our other blogs, are always welcome. Follow us through our RSS feed. For additional information or follow-up questions, visit our Forums page, or Contact Us (http://www.dipterra.com/).