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Insect FCR data?

I've been searching for data for insect feed conversion ratios, and it is difficult to find. I am wondering if someone else has data like this, maybe we can put together a table for different species.

So far, I've found the following:
Mealworms : 2.2 (from the mealworm excel file on this forum)

BSFL on chicken manure: 3
BSFL on pig manure: 4.8 (I've seen this confirmed by a few sources)
BSFL on cattle manure: 7.8
BSFL data from "From organic waste to biodiesel: Black soldier fly, Hermetia illucens, makes it feasible" organic waste to biodiesel Black soldier fly_ Hermetia illucens_ makes it feasible.pdf

Crickets: .9 - 1.6, depending on feed, from

Earthworms: 10 or more, from

I think the mealworm and bsf data is accurate, as I've seen similar results from other areas. I don't know about the crickets, because I've seen results anywhere from 1 to 5, and a lot depends on the feed. In that study above, .9 was on cricket chow and 1.6 was on rabbit feed (mostly alfalfa with some grain, ~15% protein). For earthworms, I have seen people talk about FCRs close to 1, but I couldn't find any studies or actual data to support that. I had no idea their efficiency was so low, but 10 makes me want to use BSF or crickets for decomposing animal waste.

I am interested in converting rabbit manures and bedding into protein for pigs and chickens. I currently use earthworms, but I'm not getting a lot of biomass out of them for protein. BSFL would be a lot better, and I think rabbit manure would be inbetween cattle and pig manure on FC, probably around 6-7.

I have seen at least one source include dried rabbit manure (50/50 with wheat bran) in the diet of mealworms without any adverse effects. I don't know the FCR for that, though.

Crickets might do really well, as rabbit manure is very similar to rabbit feed in composition, so the 1.6 figure might hold, or at worst, looking at 2.

Does anyone have any additional data or input they could share?


  • This is really great, thanks for pulling together all this information! We'll do some digging through our own knowledge bank over the next week and let you know what we find.
  • while I'm sure I get the idea, what dose "BSFL" stand for?
  • sorry, BSFL stands for Black Soldier Fly Larvae. They are commonly used to recycling organic wastes, especially in farm operations.

    Here's how we raise them in bins:

    Also, our earthworms are part of our integrated food production (Food Web) with rabbits and quail:

    We're experimenting with different species to replace the earthworms in this system, mainly because the earthworms are efficient at producing castings (good thing), but not very efficient in producing protein. We also raise poultry, pigs, and fish. So, a cheap protein source that we could produce from a waste stream would be a significant benefit.

    I think crickets probably have more labor required that mealworms, and BSFL are probably the lowest labor required of the 3. But the FCR of the crickets are interesting.

    That bring sup another question, does anyone have resources for cricket farming on a large scale? like what kind fo containers, crickets per unit of area, etc?
  • I found some more cricket numbers in a study by Wageningen University:

    Feed Conversion Ratio (live weight): 1.7
    Edible Portion: 80%
    Feed Conversion Ratio (edible weight): 2.1
    Feed Conversion Ratio (live weight): 2.5
    Edible Portion: 55%
    Feed Conversion Ratio (edible weight): 4.5
    Feed Conversion Ratio (live weight): 5
    Edible Portion: 55%
    Feed Conversion Ratio (edible weight): 9.1
    Feed Conversion Ratio (live weight): 10
    Edible Portion: 40%
    Feed Conversion Ratio (edible weight): 25
  • We've done quite a bit of research into large scale cricket farming, but it's not written up in a very useful form yet. We're planning to finish with the initial Open Bug Farm designs for mealworms first, then move on to crickets, but if there's sufficient demand from the community we can try to write up some of the cricket info first.
  • Also, Jakub from Third Millennium Farming released this research brochure which contains some "Efficiency for Conversion of Ingested Food" numbers, on page 17: Online Files/03. 3MF Research Brochure.pdf

    He describes this as "the ratio between the amount of food the insect consumes and the amount of weight the insect gains. For example for every 1g of feed eaten by a cricket it gains about 0.25g, giving crickets an ECI of 0.25"

    His table lists the following ECI values (with references for each):

    Cricket - 25
    Krill - 12
    Southern Army Worm - 37
    Leek Moth - 58
    Large Milkweed Bug - 64
  • hmm, so according to his data, the cricket FCR would be about 4:1.

    On the Wageningen University data, some of their figures for other animals (pigs) are off, as I know from our tests and other studies, but generally, they seem to be pretty accurate.  On their cricket data, that seems in line with other studies I've seen.

    Can you share some of your data/research on large scale cricket farming?  I've seen a lot of examples of small scale cricket farming, but I'm not sure how it scales up.  They certainly seem to be more labor intensive than mealworms, but they might be better converters of waste materials.

    On a side note, my 5 year old son found a young cricket yesterday, and we've set up a container with a bit of rabbit manure and other foods.  We'll see what happens.  So far, he's nibbled on the rabbit manure.
  • edited January 2014
    A while ago we put together a spreadsheet for estimating cricket farm productivity. I've shared it on Google Docs here:

    To make changes to values, you'll have to make a copy.

    It hasn't been verified, so take the numbers with a pinch of salt (we haven't even looked at in a while) - but it should at least demonstrate how the variables fit together.
  • Also, great job getting the next generation involved already :) It must be a lot of fun growing up on a farm.
  • thanks, yes, it is a lot of fun, and also a lot of work!  But, our kids have no problems eating insects, as we've tried real hard to avoid cultural influences on things like that.  So, they are excited when it is grasshopper eating time.
  • I was playing with some numbers last night, base on information from a FAO document on crickets, and at first glance, it appears that crickets may be more efficient in terms of surface area, but less in terms of volume, as compared to mealworms.  Does your research point to a similar conclusion?
  • I recently completed a project on this subject.  Focus was on ECI of mealworms at a daily resolution.  The methods could benefit from additional fine tuning to increase the reliability of data, but it might be worth taking a look at.  There are many references that will direct you to additional information.  It can be found here:
  • edited January 2014
    could you post the results here? I think it would benefit everyone.

    Thanks for providing the information. From your results, we're looking at 33.6% ECI, or about 3:1 FCR for mealworms on your diet.
  • @VelaCreations from our experience & research, crickets are definitely not particularly efficient in terms of volume. They need a three dimensional environment in which to hide, some separation between their dwelling and feeding areas, a separate laying area if you're breeding, space to both hide and to move around, etc. Their optimal density also varies depending on the stage of their life cycle (there's a paper on this somewhere, I can dig it up if you're interested). The good thing about mealworms is that they really don't need much complexity to their habitat; just a layer of food!
  • @bspang this is fantastic, thanks so much for sharing! We'll incorporate this data into our model. We definitely struggled to find reliable FCR numbers; this is very valuable research.
  • FCR will differ according to food, and that's a really important thing to remember.  His results were based on oats as a feed, but wheat bran with protein supplement may do better or worse.

    @dansitu - yeah, crickets don't seem to be more efficient in volume, but it looks like they are in terms of surface area.  You are right, the labor and materials are considerably high with crickets, however, their feed conversion and potential feed materials is much larger than mealworms.  So, it would depend on the specific situation as to which is more appropriate to grow.
  • Indeed. Ideally/eventually, our model will indicate potential yields across a range of different feeds and conditions. This is made difficult by how little data there is available; a major aim for Open Bug Farm is to do something about it. We'll hopefully generate a whole lot more data about conversion performance - which although likely less accurate than the results of peer-reviewed scientific research, should be useful when viewed in aggregate.

    With regard to crickets - you're right, it's yet another piece of evidence to show that we should be investigating as many species as possible!
  • yes, I agree, I wish I had more data and more species to choose from.  Like, do we know any species that we could combine for higher efficiency?  Do roaches eat mealworm frass, say?  There could be a lot of potential with integrating species along a cascading food chain.
  • There are even species whose presence benefits one another in some ephemeral way - like the tiny white mites that break down feces and dead crickets in cricket farms. They're not necessarily useful as part of the food chain, but they help keep things clean. There's so much potential for innovation with this stuff, we haven't even begun to scratch the surface!
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