The
silkworm is the larva of the silkmoth (Bombyx mori) and it is one of the few
insects, apart from the honey bee and the cochineal, which is bred by man for
its produce (silk).
The silk trade originated in China. The Chinese discovered
already in Ancient Times how this silkworm could be bred on the leaves of the
white mulberry. They also discovered how and when they needed to kill the pupa
in order to be able to fully unwind the silk thread from which the cocoon is
made.
Nowadays the silkworm depends totally on mankind for its reproduction and
it can no longer be found in the wild. Eggs take about 10 days to hatch into
larvae, from then they eat continuously.
After a while the worm will enclose itself in a cocoon made of silk.
This silk
thread is 300 to 900 metres long and more or less 10 micrometer thick. About
5,000 of these cocoons are needed to produce 1kg. of silk.
Because of industrial
cultivation of silk, we see an enormous residual fraction of pupa, which are
dried and sold worldwide as protein rich raw feed material.If you think what insects
birds eat in nature and feed their chicks, they can choose from a range of
about a thousand different ones in their habitat.
It is only normal that those
insects which live by day are caught most, because shadow insects spend most of
their time in hiding. The feeder insects which are currently bred are nearly
all shadow insects.
Silkworms however live on plants and are therefore eaten and
fed very often. The silkworms composition is therefore very different from the
other feeder insects.
They
contain a lot of fluid (88%), nearly no fat (1,6%) and still a very good
protein content (9%). They are ideal thirst quenchers for nest birds. Moreover,
silkworms have a high quality calcium (1000mg/kg)/ phosphorus (1200mg/kg) ratio
of 0,83:1.
Iron content is extremely low (6,1mg/kg). All
values are percentages of raw weight. Silkworms also contain the serrapeptase enzyme which is known to be a
very strong natural chelation antioxidant, which improves intake of calcium and
stimulates the bowel system. Analysis of the silkworm shows that it resembles
very much fish. Silkworms are therefore very healthy and nutritious feeder
insects. Because of their soft skin they contain only a little chitin and can
therefore be easily digested.
But just
because of this lack of chitin, silkworms do not have a shell and will feel
soft after the freezing and thawing process. This does not make them less nutritious however.
They also dry out
quicker and the discolouration which appears after a few hours is not a sign of
rotting but oxidation of their pigment and not harmful at all. As with all feed
insects, do not feed too many silkworms in one go.
Because the Topinsect silkworms
are bred only on the leaves of the white mulberry tree and not with an
artificial feed, they taste very nice and both birds and reptiles find them
delicious.
Topinsect silkworms must
therefore not fail to appear in a varied insect menu for birds.
ANALYSIS TOPINSECT |
SILKWORMS |
% OF TOTAL |
SILKWORMS |
Fluid |
88 |
Dry material |
12 |
|
Raw ashes |
1,6 |
|
Protein |
9 |
|
Fat |
0,9 |
|
Carbohydrates |
0,5 |
|
Starch |
- |
% OF DRY MATERIAL |
SILKWORMS |
Raw ashes |
10,7 |
Protein |
75 |
Fat |
7,5 |
Carbohydrates |
4,2 |