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.