Reproduction, Growth, Carcass
Traits - Can We Have It All? Part 3
Part 3. By Mark Gardiner, Gardiner Angus Ranch, Ashland, Kansas
In the earlier segments of this article, I discussed how my dad, Henry
Gardiner, tried to improve our herd by using prize winning bulls,
but did not have much success. That is until the first Angus Field
Data Report (Sire Summary) was published. Using that report, he was
able to make sire selection based on genetic merit for selected traits.
I also explained how, through the use of EPDs, our weaning weights
went from 546 pounds in 1980 to 847 pounds in 1999. Gardiner cattle
also improved their feedyard performance, increasing average daily
gain by 1.51 pounds/day from the late 1970s to 1999.
In this final segment, I'll detail how we select for sires, based
on all of this information.
Reproduction
Don't forget, reproduction is still the number one performance trait.
Remember that fertility is a lowly heritable trait.
According to Dr. Richard Saacke of Virginia Tech, semen evaluations
can only account for 50 percent of the variation of fertility between
bulls. On the female side, the environmental differences between neighbors
may have more affect on cowherd fertility than differences in their
genetics. I would love to place selection pressure on fertility that
would allow me to effectively select bulls or cows with higher fertility,
but I also think we should realize that we are dealing with very low
heritabilities on fertility traits.
Heterosis will have more of an effect on reproductive traits than
genetic selection during two of my lifetimes. Therefore, I believe
it is important to place a heavy emphasis on fertility as a threshold
trait. In other words, make cows conceive during a time restricted
breeding season. It is important that cows work for you and not vice
versa. Cows that do not work under their job description, need to
find a job elsewhere.
We have been able to make genetic progress and maintain a cow herd
that is reproductively efficient. Since 1964, Gardiner Angus Ranch
has had a total AI program with no clean-up bulls. Since the inception
of this program, the heifers were given 30 days to conceive, or they
exited the herd. The cows have always been bred on a 60-day breeding
season. Since 1964, our pregnancy rate (pregnancy rate = total cows
that conceived divided by total cows serviced) has been 95 percent
or greater. The bottom line is: we didn't have to compromise reproduction
to achieve genetic improvement.
Conclusion
I have heard it said that EPDs are just a fad and they will not last
long. Well this fad is well into its 21st year. Data-based selection
will become more and more a part of the beef cattle industry. As value-based
marketing becomes more of a reality, it will be impossible to survive
in the beef cattle business without a reliable database that allows
cattle breeders to react to economic signals.
We believe in EPDs. Our goal has always been to produce a live calf
that will grow as rapidly as possible to market weight and then quit
growing. We believe that you cannot have too much growth as long as
that growth is in the "right package." We use eighteen EPD
traits to select our sires.
We put a lot of selection pressure against birth weight; most of the
bulls we use are in the 2.0-pound range or less for birth weight EPD.
We also put a lot of selection pressure against mature size, so we
select sires that are below breed average for the yearling hip height
EPD, and below breed average for the mature daughter weight and height
EPDs. After applying the previous selection criteria, we select bulls
with as much yearling weight as possible.
Then we select bulls with adequate milk EPD. In general we keep our
milk in the 15-20 range, but we do select some bulls with less milk
for our customers who get less rainfall. Next, we look at the carcass
EPDs. We want the sires to be positive for marbling, ribeye area,
and percent retail product. We want the sires to be negative for the
fat EPD.
Finally, we use the scrotal EPD to make our sire selection. We would
prefer to select bulls that are positive, but we do use some bulls
that are negative for scrotal EPD. We only select sires that fit the
above criteria and are high accuracy bulls (>.80) for these EPD
traits (progeny proven). This is not a complicated system, but it
does require discipline. We believe it is very effective, based upon
what it has accomplished for us.
I'm a living example of the economic reality of EPDs. Gardiner Angus
Ranch would have gone bankrupt weaning 525 pound 10-month-old steer
calves. There would have been no ranch for us to come home to if my
Dad had not chosen to use EPDs. I would like to thank Roy Wallace
and John Crouch for all their help over the years and for helping
implement data based selection. I would particularly like to thank
Henry C. Gardiner for his tenacity to never give up, and the foresight
to recognize the economic reality of EPDs, and especially for implementing
the Gardiner Angus Ranch breeding program. My Dad and I have many
"discussions" about our sire selection, but I usually end
up reminding him "I'm only implementing the program you taught
me."
Reproduction, Growth, and Carcass traits, can we have it all? Yes!