Search Results for: silkworms

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:

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.

Even though silkworms
didn’t work as well as planned last year, I still think there may be an
invertebrate we can easily raise to turn free plant matter into food
for our chickens.  One option might be snails, which have been
grown as human food for thousands of years.  Here’s an overview of
my current research into heliculture (raising snails).



What does a snail farm look like?

You can raise snails
indoors or outdoors, with various options available for both
arrangements.  Although it requires more work up front to make a
snail-proof (and predator-proof) pen, the lowest work in the long run is
to make a snail garden, in which case you only have to water and weed
the plants and harvest the snails — check out this booklet for more information. 
You can also make a much smaller outdoor snail pen (like the one shown
here) where you bring food to your snails.  Or you can build a
similar pen indoors.



What kind of snail should I raise?

If you’re raising snails
for chickens, you probably don’t care as much about gourmet
qualities.  In this case, your best bet in temperate regions is
probably Helix aspersa (the garden snail).  Helix aspersa is
a smallish snail with a weak shell, and individuals can reach full size
in one year if well fed (as opposed to three years in some other
species).  Like most
snails people raise for food, it is an herbivore, meaning the snail
needs to eat living plant matter.  As a result, you’ll want to be
very careful to prevent this snail from escaping from captivity since it
can become a major garden pest — this may be a reason to try out
different types of snails already found in your garden on your chickens
and choose one of those natives to raise instead.



What do snails eat?

Wikipedia lists the following food plants as being favored by snails:
“Alyssum, fruit and leaves of apple, apricot, artichoke (a favorite),
aster, barley, beans, bindweed, California boxwood, almost any cabbage
variety, chamomile, carnation, carrot, cauliflower, celeriac (root
celery), celery, ripe cherries, chive, citrus, clover, cress, cucumbers
(a favorite snail food), dandelion, elder, henbane, hibiscus, hollyhock,
kale, larkspur, leek, lettuce (liked, and makes good snails), lily,
magnolia, mountain ash, mulberry, chrysanthemum, nasturtium, nettle,
nightshade berries, oats, onion greens, pansy, parsley, peach, ripe
pears, peas, petunia, phlox, plum, potatoes (raw or cooked), pumpkins,
radish, rape, rose, sorrel, spinach, sweet pea, thistle, thorn apple,
tomatoes (well liked), turnip, wheat, yarrow, zinnia.”



In addition, the
FAO article linked to above recommends planting snail gardens
consisting of rape, horseradish, leaf beet (for shelter), burdock, and Plantago sp. (for shelter).  Snails can be introduced to their gardens when the plants are five to six weeks old.



Finally,
snails also need either plants or physical objects to shelter amid
during the day, well-drained loam soil in which to lay their eggs,
calcium (either from the soil or added as a supplement) to build their
shells, and plenty of moisture.



How much space do snails need?

In modern, high-density farms, Helix aspersa
can be kept in an area with one square foot for every six to eight
snails.  If you want the snails to breed, though, you’ll need to
give them more space — providing at least 1.25 square feet of room per
snail.  In snail gardens, snails are introduced at a rate of about
150 snails per 125 square feet, or 1.5 square feet per snail.



How much snail meat will I get?

If you raise a
fast-growing snail outdoors, a 125 square-foot pen will produce about 27
pounds of meat per year.  That’s about 9900 calories, nearly all
of which is from protein.  For the sake of comparison, you can get
about four times that many calories per acre from corn, but corn is only
about 8% protein and is much less healthy for your chickens.  As a
side benefit, snails are also very high in calcium and magnesium.