Sire Selection
“
own replacement heifers, perhaps with
the idea of having some bred cows to
sell? These bulls are difficult to find.
maternal herds. “Moderate” needs to be
defined for your ranch, but the range
around “your moderate” cannot be too
large for any trait.
Most of
Fertility and longevity
the EPDs
Cows must become
along
with
the
ability
to
available
adapted to your
are not for produce an acceptable calf environment and
maternal
then be adaptable
are really what we are
traits
to year-to-year
except as
variation. Nature
looking for in good cows.
limiters—
tell you which
Bulls that make that kind will
reducing
cows to cull and
of cow are hard to find.
cow size
which bulls to
and milk,
select; but you need
keeping growth in a moderate range,
to recognize which ones they are.
balancing maternal calving ease and
There are some physical traits that
calving ease direct, etc. Moderation of
are important such as udder quality,
size, milk, growth and muscle seem to
ability to move and travel, ability to
make better long-term mother cows.
maintain body condition on grazed
The use of selection indices has some
feed with minimal supplementation,
appeal. But when “supposed” strength
feed intake capacity, etc.
in one trait can compensate for
Beyond these, I am reminded of a
“supposed” weakness in another trait,
statement heard many years ago—“We
what is an acceptable balance? When
need to quit telling cattle what to look
does high growth cause reduction in
like and, instead, tell them what we want
fertility or increase cow size (reduce
them to do and then let them look the
stocking rate) in the next generation?
way they need to look in order to do
At what level should milk production
what we want them to do.” Remember,
become a negative in the index?
we can’t ask them to do more than the
I have asked a number of seedstock
environment will provide for and allow.
breeders those questions and only one
I think there are a few people who have
had an answer; and I thought his level
learned what cows need to look like, but
was too high—purely a guess on my
most of us don’t have that skill except
part. What about epigenetic effects?
for the very obvious. So, how do you
This happens when environmental
choose a bull for maternal mating’s?
factors turn on or off (or possibly
modify) gene effects. How much of
First, the bull must be born in the first
that is heritable or not heritable?
25 days of the calving season—ideally
a result of first cycle conception. Then
While I like to get aggressive in the use
I like to know as much as possible
of EPDs for terminal sire selection, for
about closely related females. What
reasons cited, I am much more cautious
about their udders, what is their
in the use of EPDs to select bulls for
“
22 | FEBRUARY 2019
mobility, how about disposition, how
long are they staying in the cow herd,
what kind of calves do they produce,
are they always healthy, etc.?
Fertility and longevity along with the
ability to produce an acceptable calf are
really what we are looking for in good
cows. Bulls that make that kind of cow
are hard to find. Bulls that make the
good cows usually come from good cow
families—dams, grand-dams, sisters,
and daughters are almost all good.
I think that is the reason that a good
number of successful commercial
ranchers are producing their own bulls.
They select bulls from their adapted
cows that have always calved in the
first cycle. The cow must have calved
as a two-year-old and again as a three-
year-old before a bull can be kept.
The bulls must have good weight in
relationship to hip height at one year of
age. They must pass a BSE at a year of
age after minimal development. A few
breeders are breeding their yearling
heifers to their yearling bulls—only
yearling bulls—then using DNA for
parentage to know which bulls sired
the most calves. That ought to check
for a combination of fertility, libido and
structural soundness at a young age.
To have a good maternal cow herd
you must use bulls that are highly
fertile, structurally sound, that will
produce calves that have good
growth (not outstanding) and are
acceptable in the marketplace. I
This article was reprinted with
permission from the BEEF Magazine.