Project to Determine the Economic Viability of Black Soldier Fly Grubs as an Alternative Protein

2010 Annual Report for FNC09-776

Project Type: Farmer/Rancher
Funds awarded in 2009: $5,001.90
Projected End Date: 12/31/2011
Region: North Central
State: Iowa
Project Coordinator:
Mari Holthaus
Kymar Acres

Project to Determine the Economic Viability of Black Soldier Fly Grubs as an Alternative Protein


Kymar Acres has been in business since 1998 and has evolved over the years. We have 15 acres on which we currently have a 750 hen laying flock; 3 acres of vegetables, flowers and herbs; bedding and potted plant production; and 7 sheep. We had a feeder pig operation for 8 years, where the sows were farrowed in open pens, which we ended in 2008. We started vegetable production in 1998 and adjusted production levels over the years for various reasons. For example, decreasing production when the children were young and increasing production when we hired an employee to help in the accounting and farming businesses. Currently we market our vegetables, eggs and herbs through GROWN Locally, a farmer's cooperative, and local farmers markets. The cut flowers and started plants we market through farmers markets. We are planning an expansion for the 2010 growing season by starting a wholesale cut flower delivery route and increasing our started plant selection, as well as testing herb production in the greenhouse for sale during the winter.

We started with 50 laying hens in 2000 and have increased it over the years. We are licensed by the State of Iowa and candle and wash all of our eggs on site. Our chickens are currently housed in our old farrowing building and have access to pasture year round. We have developed a system in which we can use a fixed structure to house the birds and use rotational pastures to give them access to fresh grass when the current pasture is depleted. We have built a lane with various materials, hog panels with snow fence and mesh from old corn cribs, with which we can open to different pastures. We currently have 3 pastures but plan to build 2 more to ensure there is pasture available during the seasons when pasture growth is slower than consumption.

My husband, Kyle, works full time as a parts person at an implement dealership in Decorah and I also do seasonal tax work as a CPA in my own tax business. My farm work meshes well with the tax work as it occurs mainly in the winter months.

The profitability in egg production at the scale we operate is limited especially when utilizing hired labor. There are two options to remedy this problem; we can increase our prices or reduce our expenses. As we live in an area where a high percentage of the residents have low income the increase in price would limit those who could afford our eggs, which we believe are more nutritious and tastier. Not only would a price increase reduce the number of individuals that can afford our product it would affect the number of local businesses that we could market to.

We think that reducing the cost of production is the best way to improve our ability to profitably market our eggs in northeast lowa. We have reduced our cost of feed, to some extent, by providing pasture, however this is limited because of the seasons and we still need to purchase feed for substantially all of the needed protein. As protein is the most expensive part of the feed rations it would benefit our farm and others with mid-sized flocks, to find a renewable source of protein.

We would like to develop, and determine the viability, for the production of Black Soldier Fly grubs as a protein-rich feed additive for our chicken flock. The idea was brought to my attention by an article in Backyard Poultry and after doing more research have found that while the use of Black Soldier Fly grubs is not new it has not been developed in a commercially feasible way. There is a further problem for our area as the fly is not native and it will not naturally lay eggs in our material bins. After studying the problem we have developed a plan to overcome the problems in order to utilize the high protein food they provide.

We plan to test a couple of elements pertaining to the production of the Black Soldier Fly grub. First we would like to determine the rate of grub production with different materials. A second goal is to find an efficient way to keep the population in production throughout the winter months. Finally we would like to find good uses on our farm for the by-products of the growing of the grubs.

Kymar Acres would like to determine which type of material best produces the Black Soldier Fly grubs. This will be done by having three sets of testing containers with each set containing different materials. We will weigh out, and track, the materials as they are added daily and the grubs as they are harvested. We will test the use of only chicken manure, only cattle manure, as well as a combination of chicken manure and food waste from our vegetable production in the summer and cow manure in the winter. We will have three containers in each set so that there will be production in some containers while another is being reset and cleaned out, this will also provide a method of getting a better rate of production by averaging the results. There has been research on the protein content of these grubs and we then can calculate when we have weights, how much protein to take out of our feed rations and therefore the cost reduction in the feed. We will also look into which type of bin works better, a plastic one or one made out of plywood and lined with a protective material. With the information we gather we will be able to determine the cost savings of grub production.

In order to maintain a consistent supply of the grubs we need to develop a way to cultivate the grubs the entire year. In order to do this we will create a screened area where the adults will not leave during the summer and where we can add insulation as the seasons cool. As the grubs grow and consume the materials the process produces heat and we will harness this to keep a temperature high enough. In order to keep a constant temperature, to facilitate grub production, we will vent the heat created by the chickens into the grub production area and vice versa as needed, this will eliminate the need for an artificial heat source. Thermometers will be used in each container to ensure the heat is evenly distributed. By keeping the area warm enough we will be able to keep an area where some of the grubs will be allowed to mature. The grubs will then burrow into the ground from where they will emerge as adults to mate and lay eggs again. Keeping the area warm enough will allow us to have a high protein food source all year as well as allowing us to keep the population numbers high enough.

As the grubs consume the materials provided to them they create two main by-products. The process creates a large amount of moisture depending on the beginning materials, and it is supposedly much like a compost tea. The ph levels and the value as a fertilizer would have to be determined after the process has been completed. The second by-product is the remaining composted materials that the grubs did not consume. This product may be useful as a soil amendment or as a potting material in the greenhouse. The amounts of each by-products would need to be determined and will be tracked in each set of materials. If these by-products are shown to be useful they would be a good organic product to use in the production of vegetables, flowers and herbs. This could potentially create a revenue stream for those that have no use for the products or a consistent supply of material if they do.

There has been research done on the use of the Black Soldier Fly grub in manure management on a large scale. The research has been done for large hen and swine facilities showing that there is a significant reduction in material and odor. This research has been done in university settings and has not been done for the use of the grub for a main protein supply; the grubs were just a by-product of the process. There has also been work done on the creation of a home-scale unit to produce the grubs for small chicken flocks or as fish food, the size of the unit would utilize the average homes food scraps. All of this research has relied on a naturally occurring population of the Black Soldier Fly and have not been done to determine if it is a commercially viable operation.

I have purchased large plastic tubs and other supplies and have been learning extensively about the habits of the soldier flies. The first attempt I had trying to raise the worms from the grubs I brought in was unsuccessful. I had first attempted to keep the larvae in an area separate from, but attached to, my chicken facility but the environment was not conducive to the growth of the worms. I found the first summer to be much too cool and the weather too variable to get a successful repopulation of the larvae.

The second attempt was far more successful and I have been able to get the results I was expecting on a smaller scale. This was accomplished by moving the bins to the greenhouse where the temperature is higher and the environment much more stable. I have placed the material in the bins and have been able to get the larvae to climb out of the tubs into receptacles.

I have also been able to collect the liquid by-product that is produced in the decomposition process and will soon be determining how it can be used as a fertilizer.

I have learned much about the temperatures that are required to keep the larvae and flies following their natural growth patterns. If it is too cool the larvae do not die but they do slow down in their development. It appears that there was even slower development if there were significant temperature fluctuations over a short period of time, which can be a problem in northeast Iowa. This has been a bit of a problem as I was able to keep the temperature above freezing in my initial location, but I was not able to keep the temperature up high enough for the larvae to thrive. I have moved the containers of larvae to our greenhouse and have been much more successful in the reproduction of the insects.

The chickens that have been fed the larvae really do seem to prefer them, but as the quantities are limited at this time no significant change in feed consumption has been seen.

I was surprised by the amount of time it took to build up a significant population but now that I have reached it I am ready to begin monitoring the differences with various materials as food sources for the larvae. These sources include vegetable and food waste, manure and a combination of the two. I hope to determine which creates the better larvae production and what quality of liquid by-product is produced.

As the larvae production increases and begins to be consistent I plan on giving the chicken flock free choice when eating the larvae and monitoring the amount of eggs produced, their quality, and the amount of regular laying feed consumed. Over this process I hope to determine how much larvae are consumed each day and adjust the amount of protein put into the feed rations.

The liquid by-product, after monitoring, will be used as a fertilizer in both the greenhouse and field production of vegetables, flowers, and herbs. I hope to determine the amount of this by-product that is produced and if it is a good replacement for other fertilizers.

We were able to share some information on this project at our field day on June 18, 2011, with about 100 people in attendance. I discussed the project with all who were interested, however I did not have a wide scale demonstration as I was still trying to get the population built up to a useful level.

We will have another field day in the summer of 2012. At this field day we will have a detailed description of the process we followed, what worked and how much feed we were able to replace with the larvae as well as the uses of the by-products. I will also be making available ‘starter’ packs of the larvae so others can replicate the process more readily. This will be especially helpful up here as this is a naturally occurring southern insect and was only obtained by ordering the larvae through a pet food supplier.