ALLISON VAN EENENNAAM:
How are you?
Nice to see you.
Nice to see you, my friend.
How are you?
Are you good?
Yeah, I know.
So this is Spotigy
He's very friendly.
Normally, his horns would
be growing here and here,
but you can say that
they're not growing.
This guy's called Buri.
He has a slightly
different spotting
pattern, but also no horns.
So these are the
stars of the show.
The two bulls that have
been genome-edited,
so we've tweaked that gene so
that they no longer grow horns.
SPEAKER: As a geneticist
and animal breeder,
Dr. Allison Van Eenennaam
doesn't see a cow the way
that most people do.
ALLISON VAN EENENNAAM:
Things like the health
of the animal, the reproductive
capability of the animal, what
its form is like, and then
also the amount of protein
it produces.
It's a genetic basis
underneath all of that,
and it's due to the
random mutations that
happen during evolution
or artificial selection.
And while much of
her work has involved
wrangling these
random DNA changes,
Dr. Van Eenennaam's motivations
are hardly clinical.
Some of the work
we're doing with them
to try to select
for animals that
are less susceptible to disease
and to try to minimize welfare
issues, like dehorning
is really what interests
me about animal breeding.
And I think that genetics is
a really sustainable approach
to dealing with some of the
problems of agriculture.
SPEAKER: Some of these
challenges popped up long
after cattle were domesticated.
ALLISON VAN EENENNAAM: During
the development of dairy cattle
breeds, the horned
trait came along.
It wasn't necessarily something
breeders were selecting for,
but it is now fixed
in the dairy breeds,
for example,
Holstein and Jersey.
And it's not a trait
that is optimally
suited to modern
production systems,
because the animals can hurt
each other with the horns,
and they can also hurt
their human handlers.
So to prevent future
harm, dairy farmers
often burn the growing horn buds
off of male and female calves.
It's done at a young
age when the animals are
one or two months old, and
it's painful when it's done.
So typically, a Lidocaine
block is given to the animal
before the heat is
applied to the horn buds.
So that's unpleasant,
and it's not
something that is enjoyed by
either the farmer or the cow.
SPEAKER: Thankfully,
not all breeds of cattle
are given this procedure.
ALLISON VAN EENENNAAM:
As it happens,
Angus have a naturally occurring
mutation in their DNA that
makes them not grow
horns, so they're
what's called polled which means
that they don't grow horns.
It's a genetic
defect, if you will.
SPEAKER: And of course,
this leads to the question,
why can't they get
rid of the horn
trait the old-fashioned way?
ALLISON VAN EENENNAAM:
You could cross an Angus
over the top of a Holstein and
get a pole, a no-horned calf.
But you'd have this calf
that was kind of half-dairy
and half-beef, and
it wouldn't really
be ideally suited to either.
And then you'd have to
cross it back to Holstein
to get it back to
the high productivity
of a typical Holstein.
So by the time you
did eight crosses,
that's a 20-year process.
SPEAKER: And that's assuming
the random genetic changes
that come with traditional
breeding methods
work out in your favor.
It's a process cattle breeders
are not likely to adopt.
ALLISON VAN EENENNAAM: So how do
we make the Holsteins hornless?
In the case of the
bulls that we've
been working with in
collaboration with the company
Recombinetics, the
editing reagents
were brought into cell
culture, and they went in
and very precisely made a tweak
in the DNA at the gene that
grows horns to introduce exactly
the same sequence as is found
in Angus at that
particular gene.
So we introduced, basically, a
cow sequence into a cow genome,
and then those
cells were cloned.
And that's the two
bulls that we have
here on campus
that are Holsteins
that no longer grow horns.
SPEAKER: Dr. Van Eenennaam
and her team at UC Davis
is currently working on editing
embryos in a similar manner,
but it may be a while
before bulls like these
are ready for prime time.
ALLISON VAN EENENNAAM:
They're prototype animals.
It wasn't done in an
elite genetics line.
It was really done more as an
experimental proof of concept.
So there's very
elite animals that
are at the top of
the breeding pyramid.
So for example, if you
edited an elite Holstein,
then all of the daughters
that he produces
would inherit that change.
So you could make
improvements quite rapidly
in a production
system like that.
But how soon this
technology might
be seen in agricultural
breeding programs really
is 90% dependent on
regulations and 10% dependent
on scientists.
If there is an overly
arduous 20-year time frame
to bring it to market,
then obviously,
that's going to make
it cost-prohibitive.
SPEAKER: Because the
edit to the animal's DNA
is identical to
a random mutation
during sexual reproduction,
Dr. Van Eenennaam
doesn't believe this type of
change merits legal oversight.
ALLISON VAN EENENNAAM: We
don't regulate that now.
The reason that a Holstein
looks different to an Angus
is because of spontaneous
mutations and evolution,
or artificial selection.
So what's the rationale
for regulating it
if it's done by man versus
if it occurs spontaneously?
To me, there's no scientific
rationale for that.
It's just really an
ethical "man shalt
not do that" kind of statement.
SPEAKER: But she
acknowledges that there
is significant public concern
about genetic modifications.
ALLISON VAN EENENNAAM:
People's worries
have to do with transgenesis
or Frankenfish or whatever.
It's really a different
technique to that,
but I guess I would
step back and ask,
what is it that concerns
you, and to understand where
that discomfort is coming from.
I don't think people would
argue that it's better
to burn off a horn than to
genetically dehorn an animal.
So I'd like to have a discussion
not only about risks, which
is what the GMO discussion
is only ever focused on,
and discuss both
benefits and risks.
SPEAKER: For "Science
Friday," I'm Luke Groskin.
