Tullis Matson: OK.
Narrator: Depending on the stallion,
horse semen is one of the most expensive liquids
on the planet.
Matson: Thinking about it.
Thinking about it again.
Starting to draw.
Yeah, OK. You can wash that.
Good boy.
OK?
Grab that rein inside, Josh.
Got him?
[horse snorting]
Let's hold it there.
So, we collected about 80 mils,
and this is gonna be worth
in excess of $100,000.
Narrator: That means that a gallon
of this horse's semen
is worth $4.7 million.
And that's nowhere near the most expensive.
[horse whinnying]
Once it's collected, horse semen can be separated
and sold in small tubes called straws.
Matson: One of these straws is worth about $1,200.
We're putting about 150 million
to 200 million sperm cells
in each individual straw.
Big Star's produced about 60 or 70 of them here.
Narrator: Super-fertile stallions like Big Star
can ejaculate once a day.
Theoretically, this means he could produce
over $20 million worth of semen
during an eight-month stud season.
And if a stallion's semen is high quality,
it can be frozen in straws for future use.
Matson: So, in this room is the heart
of really Stallion AI Services.
This room's built like actually
a nuclear bunker in here.
This is where all the semen is now kept.
We've got hundreds and hundreds of thousands
of straws in here.
We've got over 1,200 different stallions.
So, in here, stored at minus 196 degrees,
is hundreds of millions of dollars' worth of semen
ready to be used to inseminate mares.
Narrator: In the horse-breeding world,
genetics is king.
Wealthy investors are willing to pay high prices
for proven winners' semen,
hoping that the resulting foal
provides a large return on investment.
Matson: Big Star is one of the most prolific
show jumpers of all time.
He's a double-gold-medal-winning stallion,
which, there's very few of them out there.
He's got the perfect genetics, really,
to go on to show jumping.
So you mix that with
another genetic line on the female side
and cross those two together.
You can pay $1,200 for a single straw,
you can have a foal,
and maybe three or four years later,
you can sell that foal for sometimes $100,000.
In Big Star's case, he's hit those bells.
He had the highest-price foal in the UK,
and that sold for in excess of $100,000.
Narrator: Even though most stud farms
offer guarantees on producing a live foal,
commercial and competitive success
is still a gamble, even with strong genetics.
In fact, the bloodline of all stallion horses
is closer than you might think.
According to an international team of scientists
who studied the Y chromosomes
of 52 horses from 21 breeds,
practically all modern horses
descended from just a few original stallions,
from carriage horses hauling tourists in the streets
right through to champion racehorses like Galileo,
the world's most expensive sire.
Even more surprisingly,
95% of all thoroughbred racehorses, like him,
can be traced back to just a handful of ancestors,
who are all linked to one single superstud:
the Darley Arabian, born in 1700.
But the value of thoroughbred semen
is a little harder to quantify,
since breeding must occur naturally for racehorses.
Matson: In the sport-horse world, we're very lucky.
We can use artificial insemination
to breed our mares with,
as opposed to the thoroughbred world,
everything's got to be done naturally.
They've got to literally cover the mare naturally.
Their concern with their gene pool,
if they would allow AI into the thoroughbred world,
it would mean the gene pool would shrink
because one horse could then
cover thousands of mares.
Narrator: And anyone wishing to naturally
cover their mare with Galileo
needs serious financial backing.
Even though his price is listed as private,
it's widely reported that his stud fee
sits at around $650,000,
comfortably the world's highest.
But because thoroughbred horses must be bred naturally,
and therefore a collection of sperm cannot be purchased,
equating the cost of Galileo's semen
requires some extrapolation.
Assuming that during the course of a natural covering,
Galileo ejaculates the average of 50 mil of semen,
and assuming that the semen is high-enough quality
to impregnate a mare successfully,
and assuming that a breeder paid
$650,000 for that service,
then we can deduce that a gallon of Galileo's semen
could be worth a whopping $49 million,
making it the most expensive liquid on earth.
But is it worth it?
Matson: Like anything, there's a lot of work,
there's a lot of luck in it.
But you've got to make your luck,
and you've gotta start off with the right genetics.
The chances, obviously, you need to breed a lot
to get that particular horse,
but with the right genetics,
you've got a much better chance.
Narrator: Galileo's position as the top sire
is cemented by the achievements of his offspring.
He has sired no less than 84 winners,
including Frankel,
who himself has now been put to stud,
commanding the second-highest stud fee in the UK
of around $220,000.
In turn, he has sired a further 10 winners.
Like father, like son.
Despite generally being safer
for both stallion and mare,
artificial insemination is criticized
for its ethics around science and nature.
But the analysis of thoroughbred-racehorse genetics
has added to the controversy surrounding horse breeding.
Roughly 10% experience orthopedic problems,
and the majority suffer exercise-induced
bleeding in the lungs.
PETA investigators captured video
from inside the breeding barns at Darley in Kentucky,
one of the world's most expensive
thoroughbred-breeding facilities,
where stallions were goaded to cover
more than 100 mares each in a breeding season.
Some thoroughbreds were even sold for slaughter
at a horse meat market.
With so much money to be made in racing,
show jumping, dressage, and more,
the price of horse semen will remain stable.