Maintaining a Koi Brood Stock
A group of mature koi used for
breeding and propagating new koi is known as a 'brood stock'.
Not every koi hobbyist maintains his or her own brood stock.
However, those in the business of selling koi (especially commercial
farms) can not do without one. This article discusses what
people in the koi business do to maintain a viable brood stock.
Having a reliable and viable
brood stock is the foundation of any koi production business.
Without it, a koi production business will not have a steady supply
of millions of koi fry from which to select the genuinely sellable
koi. For a koi business to have a good reputation, it must
only sell good koi, and we all know that not all koi fry will grow
to be 'pond-worthy.' It is for this reason that a large
percentage of every generation of koi fry born must be culled - so
that only the best koi will grown and sold to solidify the
reputation of the business. Thus, a business must produce much more
koi fry than it intends to sell every month.
So how many koi must your brood
stock have? Well, it depends on how much koi fry you want to
sell every month. Let's do the math. According to experts, it
is fair to assume that only 7% of koi fry born will have a marketing
potential. Thus, you can only sell 7% of the koi fry you
successfully hatch - all others are presumably not good enough
to sell and should be culled.
Koi produce about 100,000 eggs
per kilogram of weight. Now, assuming that each of your female
koi is medium-sized and weighs 2 kgs., then each of them can produce
200,000 fry every spawning. Thus, you can expect to get 14,000
koi fry to try to grow and sell for every female that successfully
This means that a small brood
stock consisting of 3 medium-sized females and 3 medium-sized males
can give you 42,000 baby koi every year, assuming that each female
is made to undergo just a single spawning annually. This is a
conservative number for an annual production since in reality,
efficient koi farming methods and multiple spawning cycles will
allow a koi enterprise to produce 3 million koi fry a year with just
70 pairs of koi. By the way, experts say that one has to take
into account the fact that 25% of the brood stock needs to be
replaced every year due to unforeseen losses for various reasons.
Your koi brood stock must
consist only of mature (2 to 4 years old) and healthy koi with
absolutely no deformities. Brood stock koi must also possess
all the best qualities of a koi, from perfect body conformation to
high-quality colors and well-distributed patterns. Excellent
koi will still produce unacceptable fry, but there's a higher chance
of getting great koi from great parents. This is why koi show
champions command extremely high prices.
Once you've selected and
acquired your initial brood stock, you can just add more as needed
and replace those that are lost or become unfit for breeding.
The important thing is to keep your entire brood stock healthy and
fecund at all times.
Koi can spawn naturally twice a
first spawning usually being more productive than the second one.
The second spawning is also referred to as the 'late spawning'.
Since temperature plays an
important role in koi reproduction, the time of the year during
which they spawn may differ from country to country. In
tropical and subtropical countries, the first spawning of koi
usually occurs during the months of March or April while the second
one usually occurs in the months of July or August.
Isolation of the spawners in preparation for actual spawning must
therefore be done in February and June for the first and second
spawnings, respectively. To read more about the basic method
for koi breeding, see Basic Koi
After every spawning activity,
the spawners must be returned to the main pond where they are
maintained until it's time again to isolate them for spawning.
Koi brood stock must be
properly fed in order to stay healthy and prolific. They must
be provided with a balanced diet that includes various nutrients and
vitamins on top of protein. The food must make the koi healthy
but not obese, since obesity is also bad for koi.
Complementing koi pellets with natural foods is recommended.
Koi that have just undergone spawning are exhausted (and possibly
injured), and will therefore benefit the most from proper nutrition
which will aid in their fast recovery.
Koi Breeding Considerations;
Basic Koi Breeding