In the wild,
invertebrates make up over half of a chicken’s diet, and Mark and I
have been looking for just the right cultivated invertebrate to use as
homegrown chicken feed. Black
soldier flies would
be great…if we had more food scraps. Earthworms are handy…if I was willing
to lose a lot of my castings as the chickens scratch through in search
of the worms. Mealworms are supposed to be
tasty…but have to be grown on grains. We’ve even considered
outside-the-box solutions like grasshoppers (although I’m not sure
anyone raises them in confinement) and water snails (with crushing the
shells being the troubling point there).
After years of pondering and
reading, I think we’ve finally found a species worth trying —
silkworms! In his excellent book, Paradise
Lot, Eric Toensmeier
wrote:
are easy to raise…. We keep the silkworms in a cardboard box,
feeding them fresh leaves twice a day. When there get to be too
many worms, which are full of fat, protein, and calcium, we feed some
to the chickens. By the time they reach about two inches long,
they are mostly made of silk and lose their food value for chickens.”
Toensmeier goes on two
write that he lets about twenty of his silkworms reach adulthood and
lay eggs, and the cycle continues. When mulberry leaves are in
short supply, he simply puts the eggs in the fridge to delay hatching
until more leaves have unfurled.
I’m not sure why I never
considered silkworms as chicken feed. They have a long history of
being fed to people and animals (especially pigs, chickens, and fish)
in China, and I recently read a vivid description of the place of the
silkworm on a nineteenth-century Chinese farm in the fictional Dragons
of Silk. In
fact, the worms are thoroughly domesticated — probably even more so
than the honeybee — so they’re easy to raise.
Various modern studies have
explored the possibility of feeding silkworm pupae to chickens, with
most finding that silkworm pupae can replace between 10% and 20% of a
chicken’s diet. Feedipedia reports that fresh silkworm
meal is 55% protein (although about a quarter of that is indigestible
chitin), while on the negative side, other sources report that the high
percentage of fat can impart a bad taste to eggs and meat if you feed
too much. These large-scale studies focus on the less palatable
life stage of the
insect merely because it’s a byproduct of the silk industry, but I’d be
tempted to follow Toensmeier’s lead and feed silkworms at the
caterpillar stage.
Stay tuned for another
post on choosing the best kind of silkworm eggs and raising silkworms
at home.
You have a mulberry tree, I presume? We had three fruitless mulberries in our yard growing up in California — wonderful trees for climbing if you don’t prune them back as dramatically as is fashionable for urban and suburban mulberry trees — and every year we’d get a number of children knocking on our door, asking if they could harvest leaves to feed the silkworms they were raising for a class project. I haven’t seen any mulberry trees since moving to Michigan, though, so I’m guessing they’re a more southern tree. They’re like weeds in SoCal; they’re everywhere. (I also used to make shoes and baskets from the leaves and just about everything from teepees to bows and arrows from the branches; they’re a pretty awesome tree to have for kids all around.)
Having raised silkworms a couple times in a shoebox, I will say one thing: they stink. Either be prepared for the smell (certainly worse than a worm composting bin) or use something better than a shoebox. Given that you’re looking to raise them on a larger scale than for a class project, I’m guessing that shoeboxes aren’t going to cut it for you, but do keep ventilation in mind when you design their home.
Bess — We have three small mulberry trees, and I just transplanted six more little ones from my mom’s yard this weekend. Hers are like yours — fruitless ones (in her case, probably paper mulberries). Fascinating to hear about your neighborhood kids coming asking for leaves!
My goal is to raise them on the porch, but I suspect Mark will also do a lot of experimentation to come up with the best living environment. I had a feeling there would be a lot of poop involved from the amount of leaves I read they eat. 🙂
I would like to say don’t give up on the BSF
They eat protein waste and all kinds of manures.
If you have livestock you certainly can’t tell me you don’t
have enough of that!
Easy to keep just add a net over a structure and you can keep
growing a big supply. you at the videos of BSf on my website
I think it’s video 21 and 22 on the playlist shows how to build the
housing structure for a godzillian fly/larvae. this is my first choice
for an aquaponics system. Jon
jonkirby — We have a big garden, so all the manure goes straight there. And all kitchen scraps go to the chickens. There really is no spare on either part — we bring in manure off-farm to have enough….