Replace Soy with Mealworms as a Protein-Rich Animal Feed Supplement

Reader Contribution by Abe Connally And Josie Moores and Velacreations
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Quality protein is essential to the healthy growth of any omnivore or carnivore, whether it be pig, poultry, fish, reptile, canine, or human. Soy fills this need, but it has an increasingly large environmental footprint and its mass-scale production is anything but sustainable. Finding a cheap and easy alternative to this greedy crop has become imperative, and that’s where mealworms come in.

The Dark Side of Soybean Production

The majority of soy produced worldwide is used as a protein supplement for animals, while a lesser proportion is grown for human consumption and for biofuel. Between the three markets, a huge demand for soybeans has developed, and it is causing a massive problem.

To produce one pound of soy, it requires over 240 gallons of water (Save Our Water), 17 square feet of land (USDA projects record crop production), and it releases 0.86 pounds of CO2 into the atmosphere (Tofu Carbon Footprint). It also is important to note that about 90 percent of soy grown in the U.S. is genetically modified and needs a large amount of herbicides, mostly fossil fuel based. Because of this drain on precious natural resources, soy production has become a leading cause of deforestation in places like Brazil (Wikipedia: Deforestation in Brazil).

The Soy Alternative

Soy protein is often hailed as a “green” replacement for meat. However, it is the use of soy within the meat industry that is largely responsible for the emissions and carbon footprint of livestock production.  If animals didn’t consume so much soy, they would be considerably less harmful to the environment.

So what’s the alternative? At first glance, there doesn’t seem to be much of a choice available for efficient protein production, and soy is currently the cheapest on the market.  But for the small-scale producer, there is a little known option that can be produced at a fraction of the cost and environmental impact of soybeans.

Enter the mighty mealworm.  As far as insects go, mealworms don’t look that impressive.  They are about 1-1/2 inches long, a tannish yellow color, and spend most of their time under the surface of their substrate (they don’t like light).  The adult form is called a darkling beetle, a primary decomposer within forest ecosystems. They only live a few months, but they breed prolifically. They are typically considered a pest in granaries and cereal stores, because they thrive on “meals” made from grains and grain byproducts.

Under this unassuming exterior lies a powerful tool for farmers and consumers alike to produce cheap protein in a small space.  Mealworms are extremely efficient at converting food into bodyweight.  It takes about 2 pounds of food to produce a pound of mealworms.  Compare that with a cow, which has a ratio of 8:1. Mealworms have another advantage: they are consumed whole, compared with larger livestock, whereby 50 percent of the bodyweight is composed of bones, offal, and other inedible portions.

Mealworms thrive in cramped conditions and are at least 17 times more productive per unit of space than soy. They require less than 1/2 gallon of water per pound of mealworms produced, making them 500 times more efficient than soy in terms of water use. They also eat a wide variety of waste streams, including grain by-products, dried weeds, and even manures from other animals. You’d be hard pressed to match this level of resource efficiency with any common livestock or crop grown today.

Aside from the protein production, mealworms also produce another valuable resource: frass. Mealworm frass is a dry, odorless waste product.  It is easy to handle and store, and doesn’t have the same drawbacks as other animal manures. It retails for $15/pound or more online. Frass has N/P/K values of 3.66 percent, 1.40 percent, 1.62 percent, respectively, and a Carbon/Nitrogen ratio of 9.86, making it a quality fertilizer and great addition to composts or topsoil.

Mealworm Farming

The most common food for mealworms is wheat bran, a byproduct of wheat.  But, as mentioned earlier, mealworms can eat a wide range of other things too, including oats, dried grasses, straw, grain/feed dust, agriculture waste, and herbivore manures. Many of these potential mealworm meals are considered waste streams, which means that they are usually in plentiful supply, and are often free or very cheap.

Furthermore, when waste products are thrown away, they often become problematic. For example, animal manures can pollute water supplies and contribute to climate change through methane production. Similarly, lawn clippings clog landfills and municipal waste management systems. Using mealworms to process these wastes can not only provide us with an alternative to soy, they can also greatly reduce the bulk of organic pollution in our waste stream.

Mixing herbivore manure with a carbohydrate source, like bran or grass, we can provide a balanced diet for mealworms. We mix the manure and carbon at a 1:1 ratio, and with mealworms’ FCR of 2:1, that means for every pound of manure we feed them, we get a pound of mealworms out.

Seeing as mealworms do not like the light, we designed our Mealworm Farm (Instructables: Mealworm Farm) as a tower with closely spaced shelves. Not only does this make their habitat a little darker, but it is also extremely space efficient. It takes 1-1/2 square feet of space to produce 1-1/2 pounds of mealworms a week. Furthermore, we made each tray different, according to the different stages of the insect’s life cycle. The trays with growing worms all contain screened bottoms, allowing the frass to filter down and be easy to collect, ready for use on our garden.

Mealworms in Livestock Feed

So, how do mealworms work in livestock feed? The answer is that mealworms are a high quality protein source, and can replace the use of soy in any omnivore’s diet. Poultry relish the mealworms, and the wiggly treats are a great way to tame any bird.  Gecko and lizard owners know the power of mealworms, as they are the default live food for many of those animals. Dogs, cats, pigs, and fish all enjoy mealworms raw, and will quickly ignore their commercial ration in favor of the tasty larva.

Mealworms have 48 percent protein by weight (Feedipedia: Mealworms), which is similar to soy’s 50 percent protein (Feedipedia: Soybean meal). Mealworms contain more total energy per pound, however, and have lower ash and crude fiber content.

Just like soy, they need to be mixed with other feed sources, as a pure protein diet is not healthy or balanced. Mealworms can be dried for grinding and added to commercial rations using existing infrastructure, and require less processing than soy. Combined with their lower resource consumption and cost, mealworms offer a real option as a protein source for animals.

Mealworms in Human Diets

Humans can also eat mealworms, and the growing entomophagy communities in western countries recommend mealworms as the perfect starter insect.  They can be fried, toasted, sautéed, powdered, and even made into ToFu! They are very tasty and their appearance is simple, not a lot of legs and antennae to scare dinner guests.

An average adult requires some 400 grams (.88 pounds) of protein per week. An optimized mealworm production system (How To: Mealworm Farm) can produce this in less than 2 square feet of space. This is smaller than most refrigerators. Imagine a protein supply in a spare closet or room, producing protein and garden fertilizer on a regular basis. This is only possible with efficient insects, like mealworms.

FAO has been promoting insects as viable protein sources for humans (Insects for Food and Feed) as a way to reduce the environmental impact of meat. And using insects as a meat supply marks a significant reduction in that impact, mainly because of their efficiency. But these studies go only so far, as they assume feeding insects grains and soy, so they are basically replacing a cow with a mealworm. While this does reduce the overall footprint, there still remains a significant impact associated with this practice.

We can do much better than this. It seems illogical to use valuable land to grow grains for insects; they have not been bred for decades to eat grain-based diets, so why use such a resource intensive feed source? Keep the grains for the humans and use other feedstock, preferably ones that are considered waste or by-products, for the insects. That way, we can start the relatively new practice of farming insects on a much more efficient, sustainable foundation than some of our older agricultural methods.

The Future of Farming

Integrating our meat and livestock production with waste streams makes both common and financial sense. Waste streams are abundant and often free. We already have most of the infrastructure in place to handle these resources, so it’s a matter of rerouting them through the appropriate areas. While insects are the logical first step, they are by no means the only option. Rabbits, chickens, pigs, and many other livestock can be easily integrated with the enormous organic waste streams that humans produce.

We’ve developed a framework for designing integrated farming systems called Food Web (Food Web: Raising Food the Right Way). Food Web enables the small-scale producer to design entire “webs” around local resources, like waste streams. By selecting appropriate animals and connections, we can produce significantly more food without additional feed inputs.

Food Web makes use of insects, like mealworms, to convert manures and waste products from one animal node to provide feed to another. The perfect example of this is seen in the use of rabbit manure to produce mealworms for your chicken flock. The more rabbits you have, the more chickens you can feed with mealworms.

Replacing soy in both livestock and human diets will become a necessity as resources continue to dwindle. For the small-scale farmer, this means exploring all options from a DIY perspective. Mealworms appear to be a great option for this niche, and although many people may object to a mealworm burger in the foreseeable future, feeding your chickens and pigs with mealworms is not only doable, it’s easy, cheap, and environmentally sensible.

Fore more information on DIY integrated homesteading, visitVela Creations.

Photos by Josie Moores

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