From Mauricio.Rosales@fao.org Fri Jun 29 09:51:49 2001 Date: Fri, 29 Jun 2001 00:04:59 +0200 From: "Rosales, Mauricio (AGAL)"To: "'LEAD-AWI-ECONF-L@mailserv.fao.org'" Subject: LEAD-AWI-ECONF-L: Contribution from Oliver and Sheppard on Manure Treatment [ The following text is in the "iso-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Paul Oliver and Craig Sheppard describe a manure treatment system in which that manure is rapidly decomposed by the larvae of the black soldier fly. Thus the amount and volume of the manure is greatly reduced, odour and pathogen problems are minimised and the treatment process produces a high value product (fly larvae) which can be used as feed for livestock or fish. A little more extensive description of this apparently promising system to make best use of resources will be presented on the AWI web site. Moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Message from Paul Oliver, XPOlivier@cs.com The larvae of the black soldier fly (Hermetia illucens) have voracious appetites for all types of putrescent waste: 1) farm waste from plants, animals and birds; 2) food storage waste from silos, granaries, warehouses; 3) food preparation waste generated in the sorting, grading, peeling, cooking, canning, freezing, drying and packaging of food; 4) institutional, restaurant and domestic kitchen waste; 5) plate waste or table scraps; 6) sewage waste. Black soldier fly (BSF) larvae have large and powerful mouth parts enabling them to shred and devour waste as soon as it is made available to them. Complex organic compounds that are digested by these larvae long before they have had a chance to decompose thermophilically or anaerobically, thereby conserving energy within the waste and immediately eliminating smell. BSF larvae have very efficient digestive systems, and the residue they leave behind represents but a fraction of the original weight and volume of the waste. Food waste (in the United States) typically reduces by as much as 90% in weight and volume, along with a 15% to 30% yield of live larvae of a 44% dry matter content. Chicken waste and pig faeces reduce by as much as 75% in weight and volume along with a dramatic reduction in phosphorous, sometimes exceeding 50%. The larval dry matter consists of approximately 42% protein and 34% fat. The larvae can be fed right back to the animals or birds that generated the waste, and they are particularly attractive to many types of aquaculture that demand or prefer living food, such as bullfrogs, bass and crappie. BSF larvae have been very successfully fed to catfish and tilapia. The larval residue is dry, friable and odourless. It can be used as compost, or it can be ground up and fed to earthworms or red worms for a second round of bioconversion. After approximately two weeks of feeding, BSF larvae reach maturity at a size of about 25x6 mm and a weight of about 0.2 grams. They then set out in search of an ideal pupation site, sometimes travelling as much as 50 feet. It is this remarkable migratory behaviour that makes them so easy to harvest. If provided with a ramp (of an angle < 45 degrees) at the edge of the waste, the mature prepual larvae easily crawl out of the waste. Upon reaching the top of the ramp, they crawl through a longitudinal slit in a horizontal pipe. The larvae crawl long this horizontal pipe until they reach a vertical downspout, that discharges into a bucket or container The larvae are totally self-harvesting without any mechanical or human intervention. Nothing could be simpler or easier to manage. In tropical climates, virtually no entomological expertise is required beyond the initial seeding of the disposal unit. Wild populations of BSF females continually furnish eggs to sustain the process. Since the adult black soldier flies do not possess mouth parts and do not feed upon the waste, they are not associated in any way with the transmission of disease. Only egg-laying females visit the disposal unit, and if provided with suitable oviposition sites above the waste, they do not even come into contact with the waste. Two types of bioconversion units are currently in use. The first (called a domestic or batch unit) is simply a container with at least one side at a 45 degree angle or less. The second (called a commercial or continuous unit) is a suspended track that allows for the automatic removal of larval residue by means of a scraper. Both devices can be situated right under the animal, birds or even humans generating the waste. The former is ideal for the disposal of a relatively small quantity of waste, while the latter is ideal for the disposal of a relatively large quantity of waste, especially from confined animals or birds. Paul A. Olivier, Ph.D., Engineering, Separation and Recycling LLC USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Message from Craig Sheppard, sheppard@tifton.cpes.peachnet.edu I would like to introduce a manure management system than can reduce the environmental damage sometimes resulting from large accumulations of manure. In this system manure is much reduced in bulk, nutrient content and moisture and a high quality animal feedstuff is produced. Less land is necessary to apply the manure residue at agronomic rates. This system requires relatively little capital and labor and should be useful to small as well as large animal production units. This system supports the needs of AWI by reducing the mass and moisture of the manure residue making it more economical to transport. Many of the nutrients lost from the manure are captured as high quality animal feed. This system is driven by the black soldier fly or Hermetia illucens (L.). This is a non-pest tropical/subtropical fly that can convert manure to 42% protein, 35% fat feedstuff. This has been fed to poultry, swine , several fish and live to frogs with good success. This local feedstuff production will reduce the need to import concentrates. One study found that chickens fed insect larvae as their protein source had a "more intensive taste" and may be more like the highly desirable local fowl mentioned in this conference. The H. illucens larvae are raised directly under the confined animals(or fowl) in a simple, shallow concrete basin (0.3-0.5 m), so no extra facility is needed. These larvae occur in a ~2 cm thick layer and consume the manure immediately. You really have to see these larvae in action to believe how dynamic this system is. This rapid consumption and aeration prevents the putrification and odor that often occurs and also dries the residue. Dense populations of these larvae eliminate house flies through competitive displacement. House fly control is the reason I began studying H. illucens.. The larvae require fresh manure for good growth. We tried 5 day old hen manure and got about half the biomass conversion that we saw with fresh manure. So right under the animals is the best place for them and no manure handling for the farmer! House fly studies in the literature indicate that bacteria and maggots are competitors. The maggots require fresh aerobic manure. There have been many other attempts to use various fly larvae to convert manure to useful feedstuffs. Most of these used the house fly. It is a good converter, but being a pest and disease vector, it requires a costly insectary to contain it. Also it must be harvested by floatation or some other mechanical method, adding more expense and labor. Hermetia illucens prepupae have the wonderful habit of crawling 20-30 meters or more to find a quiet pupation site. They are collected for use as feedstuff with a simple (passive) ramp and pipe system. At this life-stage they cannot feed. With an empty gut they are a neat package of protein and energy. Sixty tons can be collected from a large(100,000 hen) house in 5 months. These are 44% dry matter when fresh. These can be fed fresh or processed for transport. Simple sun drying works fine, and we have had them rendered into a protein meal and oil using the same process used to produce meat and bone meal, or poultry meal. While assimilating nutrients from the manure the H. illucens larvae reduce the manure bulk to about half that of same age unoccupied manure. The N content is about 20% less in the residue, so you get a total of about a 60% reduction in N. Phosphorous is about the same concentration in the residue, so you only get about 50% reduction P. These nutrients that the larvae has harvested in its biomass are now worth about the same as meat and bone meal or fish meal. Thus these nutrients can be economically transported great distances, unlike the relatively low value manure. We are still trying to get this in the hands of US producers. We have recently learned to culture this wild- type fly, which will make it practical for our fully confined animal housing. Hermetia illucens adults generally will not enter a closed building, but in open sided hen or swine housing the wild populations do a good job. We are getting good support lately for this novel idea and have more studies planned. Mr. Tran Tan Viet, Univ. of Agriculture and Forestry, Ho Chi Minh City, Vietnam has been developing systems to use H. illucens to manage swine, poultry and even human waste. Incidentally, the H. illucens used to be called the privy fly in the southern US and I have seen it, myself, eliminating feces and controlling house flies in that situation. Mr. Tran is also establishing a very large waste food handler using the H. illucens. This keeps the waste food out of the landfill where it can also cause ecological problems. I mention Mr. Trans's work in Vietnam to demonstrate that this system is practical and also in the hope that Mr. Tran will add to this discussion. Below are a couple of websites that give more information on using H. illucens for manure management. I wish these were more current, but I believe they will be helpful. Swine manure conversion rates to H. illucens prepupal feedstuff are better than indicated there. We found that with a simple passive drain system, swine manure was dry enough (about 70% moisture) that H. illucens could effect about a 15% conversion (d.m. basis) of manure into the high quality feedstuff. With hen manure we see about an 8% d.m. basis conversion to prepupae for feedstuff. In a recent catfish feeding trial H. illucens prepupae were use to replace all of the fish meal and a good deal of the soy. The websites for more information are: http://nespal.cpes.peachnet.edu/ Once at this site click on "Research", and then click on "Manure Management". Also; http://www.ads.uga.edu/annrpt/1995/95_311.htm This one has a good many references in the scientific literature that may be of interest. Yours for Better Manure Management, Craig Sheppard