According to the EPD
world and
modern day bovine research, reproduction performance has a very low
inheritance
rate; therefore there is no reason for cattle producers to select for
something
they have been told that they have no control over - right?
I totally disagree.
Selecting for reproduction traits is no more
difficult than breeding the horns out of a herd by using a polled bull
for
consecutive seasons.
Horns could be bred
back into a herd as well if that was a goal.
Many reproductive traits are as visible as horns and when one
learns how
to select seed stock that exhibit these traits, the gene pool with be
further
concentrated with each succeeding generation and the hereditability of
such
desired traits will greatly increase.
When
discussing heredity it’s a matter of dominant and recessive genes that
govern
the expression of the trait. For
instance if a homozygous polled bull is bred to horned cows, all of the
calves
would have a dominant polled gene from the sire and a recessive horned
gene
from the dam, yet they would all appear as being polled.
But if instead the polled bull was
heterozygous, then half of his offspring would be horned and half
polled. If all horned animals were
eliminated from
the breeding herd, it would only be a matter of two more generations
(assuming
a homozygous polled bull was used again) to completely eliminate horns
from the
herd.
The
anatomy and physiology of an animal is
directed by the genetic material it receives from its parents, so why
would
reproductive traits be any less inheritable then others?
There’re not.
What has happened is that the schools and universities who are
suppose
to be teaching and guiding us have been too focused on rate of gain;
rate of
gain on grain. Because they have not had
the true burden of making a living and supporting a family with a
livestock
business as the sole income, they have not had to purposely concentrate
and
learn how to select animals that will pass on desirable reproductive
traits. I feel certain that some quality
animals (animals with the correct reproductive traits) have come and
gone
through university programs. But
because they weren’t paired with like quality animals, and also the
fact that
the practice of crossbreeding has diluted the gene pools, the resulting
offspring didn’t possess the reproductive traits expected.
Therefore it was decided that such traits had
a low inheritance rate.
Another
misconception that has infiltrated cattle production is the notion that
“good”
cows are what count. The bull has been reduced to merely the
impregnator. Cows will always get the
credit for producing
nice calves. How can one evaluate
reproduction traits in the cow and leave the bull completely out of the
equation? The fact is you
can’t. Last time I checked, the bull was
responsible
for half of his offspring’s genetic make-up. You cannot increase or
improve
reproduction in cows without the use of a very fertile bull.
Most
seed stock producers including those that line breed look to the cow
for all
reproductive performance traits. They
give her full responsibility for the quality of her daughters and sons. Breeders use a bull because he is out of a
particular cow or cow line that they like.
In many cases these cows are the matriarch of the farm. So often there is no regard for a sire’s
ruggedness,
masculinity, testicle size and shape, or quality of semen at puberty. A bull (son) from one of these QUEENS OF
SHEBA mothers possesses more maternal characteristics than paternal.
The
result of using this type of bull selection for breeding is that one
will have
a pasture full of decent females, but the bulls will be frail, fragile,
and far
from masculine. Most breeders shy away
from using a real masculine bull for misunderstood reasons like they
will cause
calving difficulties.
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America’s
cattle herds are made up of female dominated gene pools.
These gene pools effectively create daughters
that are clones of their mothers.
Unfortunately the male calves are clones of their frail, fragile
fathers.
This type of breeding may be
alright for the feedlot-grain industry, but it will not work for grass
fed
cattle.
The basic ground rules of any
cattle breeding operation start with having cows that drop a live,
healthy calf
every year on time.
Females have the
innate ability to recreate themselves in their daughters through a
genetic
process know as cytoplasmic inheritance.
This process has the dynamic ability to override and in effect
mask
inferior traits passed on by the sire.
I
call it an act of God’s grace that saves us from our continued breeding
follies, but it is a double edged sword that has caused the epidemic of
inferior bulls.
Cytoplasmic inheritance
is terrific when all of the mother cows already possess all the desired
traits
necessary for high performance on grass.
Does that describe your herd?
My point is that in order to make
improvements (growth, carcass, grass utilization, reproduction) in your
females
or males, it requires using a very fertile, masculine bull.
It is widely taught that crossbreeding and
outcrossing will improve reproduction in the cow.
Don’t
be fooled by the higher reproduction
and growth performance that occurs in the first year’s offspring.
The generations following will be even more
mongrelized and you will loose control of the traits you were selecting
for in
the first place.
Your holy grail will
crumble.
Reproductive traits are as visible
as horns and they start to become obvious within months after birth.
The stifle muscle becomes more pronounced
with the onset of estrogen production.
Early maturing female calves will show this by 3-4 months.
Late maturing females do not have this stifle
muscle development before 4 months.
Early maturing females should be actively cycling by 5-7 months
of age
which triggers udder development.
A yearling heifer that has
developed a nice little maiden udder with four well formed nipples
pointing
towards the ground is a visual indicator of her reproductive abilities.
We know for reproductive performance a
yearling heifer’s rump is to be 2.5 inches wider than it is long.
A reproductively sound female will naturally
carry a ¼ inch of back fat by 12 months of age.
This is her energy reserve that will foster her ability to start
cycling
again soon after calving.
A side note about females that
naturally carry a layer of back fat:
Most often these types of cows need to stay working.
In other words they need have that nursing
calf at their side until it reaches about 10 months of age in order to
maintain
a condition conducive for easy conception.
When we wean the calf from this type of female at the 205 day
period,
she may become fat and difficult to get pregnant.
All
too often these cows get sent to market
because they are jaded as unbreedable when in reality it was ignorance
and
mismanagement that was the problem.
Another accurate method for
selecting for reproductive performance is to physically palpate the
uterine
bodies and ovaries of yearling females.
This will show exactly where they are in their reproductive
tract
development.
It is critical to have early maturing animals
for high reproductive performance and efficiency.
If
a yearling female’s internal reproductive
tract is small and her udder (external) is also small, she is still in
a
juvenile stage and will mature late.
If
her ovaries are developed enough to cycle yet her uterus is still
small, she is
still late maturing.
Either way
longevity is not in her favor.
A
young heifer should reach full puberty by 12 months of age, but I do
not
recommend breeding any heifer before she is 20 months old and I believe
24
months is even better.
Although she is
receptive and able to conceive, a female is not mature physically
before 24
months.
To limit the amount of nutrition
available for a heifer’s growth in exchange for a developing fetus will
only
compromise her longevity.
Pregnancy at
this stage will retard her physical development and maybe even stunt
her for
life.
The cows that get pregnant,
maintain that pregnancy, raise a healthy calf, and breed back easily
year after
year are the ones that have been allowed to mature before their first
conception.
The wild animal kingdom is
proof of
this.
These early cycling, early
maturing females will pass their reproductive traits onto their
daughters and
when managed properly will sustain your grass-based operation.
So where does the bull fit into this
reproduction performance equation?
He is
half of the genetic make-up of all his offspring.
You
may say, “Well of course”, but yet so
many breeders put their emphasis on the cows and fail to realize the
harm
they’re doing by using a mediocre or even worse - inferior bull on
those cows.
I repeat - selecting for optimum
reproductive traits is no different then selecting for polled or horns.
The testicles are the factory for the male
genetic material that is to be passed on.
A small or defective factory produces a limited amount and/or
defective
sperm.
There are several levels of semen
quality.
What kind of factory is
responsible for producing your next calf crop?
To assess the ability of the
factory is to evaluate the confirmation of the testicles as well as the
sperm
that comes from them.
Testicle size and
shape, placement of the epidydimis, testicle texture, scrotal skin and
crease,
scrotal neck, and amount of primary and secondary abnormal sperm are
all
physical features that indicate level of reproductive performance.
Early maturing, amount of muscle development
(masculinity), and libido (sexual prowess) are visual indicators of a
bull’s
reproductive traits.
Any defects in
these various traits will be passed on to the sons and daughters.
The goal is to select against any defects.
A bull will have the genetic
ability to reach a certain quality and level of semen production.
If that genetic level is high because his
parents were selected and bred for that level, then he too will pass
those desired
reproductive traits on his progeny, both sons and daughters.
If he is a bull that has a 60-75% live semen
count (forward moving) and any higher than 8-10% abnormalities, he is
low in
reproductive performance traits and will not improve reproductive
traits in his
offspring.
Just like other inherited
traits, reproductive traits are part of the genetic material located on
the DNA
in the nucleus of the sperm and egg.
The
Rotokawa bloodline Red Devon Bulls that the
Bakewell
Reproductive Center
promote test above 80% live semen with less than 5% abnormalities
(primary and
secondary).
Dr. Richard Sacky found that when a
group of bulls were put in the same pasture with a herd of cows that
75% of the
calves were sired by just one bull.
Many
if not all of the other bulls had inseminated the cows, but it was the
bull
that possessed the highest level of masculinity and libido, the bull
with the
highest level of testosterone and thus semen quality that had actually
fathered
the calves.
In his research he also
discovered
that the ovum had the ability to select which sperm cell could
penetrate its
outer membrane and enter for conception.
In his studies the cows’ ova were selecting the strong semen
from the
virile bulls for fertilization.
In order to make genetic progress
involving the reproductive traits, the sire must posses a high level of
masculinity and the dam must posses a high level of femininity, both by
12
months of age.
Only then will you begin
to produce uniform offspring with predictable results.
I have mentioned several physical, visual,
palpable characteristics in both the bull and cow that indicate level
of
reproductive performance.
To select for
these traits and leave the bull out of the equation leaves the entire
burden
upon the female.
God did not create
either sex to work alone, not when it comes to creating and
strengthening the
next generation.
You will not put reproductive
performance back into your herd without using a bull that exhibits all
the
required reproductive traits discussed.
Without a very fertile, virile bull the inheritability rate of
reproductive traits stays low just like the industry research and EPDs
lead us
to believe.
Remember you cannot put horns on a
bovine without using a horned sire and you cannot remove horns without
using a
polled sire.
The next time you hear how
reproductive traits have a low inheritance rate, tell them you know
different.
Pay attention to the bulls
you use.
Start with anything less, you
end up with less.