April/May 2008 Issue (pdf - 7794 kb)... - Hereford America

6 • www.herefordamerica.com HEREFORD AMERICA • April/May 2008
Effective selection for efficiency RFI offers an improved
alternative to traditional efficiency measures
Reprinted with permission of
Western Livestock Reporter
Columbus, Mont. - One of the most
basic economic principles is to increase
profits then increase efficiency for
optimum results.
This economic principle has been
studied and proven for centuries, and
if it is so simplistic, why hasn’t the
cattle industry mastered this concept?
Technically it has tried, at least to the
best of its ability. Many breeders have
tried to select for more efficient cattle
by studying the feed efficiency or feed
conversion ratios of their cattle when
it was available and others have
calculated a percentage of body weight
weaned. However, the impedance to
this is lack of information available to
cattle producers before breeding
decisions or bull purchases and no
reliable measuring method. To further
compound the problem is traditional
efficiency measures have “tag-along”
traits that are also impacted by selection
for traditional feed efficiency and thus
“total system efficiency” is not easily
achieved. But now an improved method
of calculating efficiency has been
developed that measures residual feed
intake (RFI) or as some refer to it net
feed intake.
RFI is a measure of true feed
utilization and at its most basic level
measures differences in metabolic
efficiencies. The concept of RFI is
measuring the amount of feed an animal
consumes above or below its
maintenance requirements as well as its
performance (growth) levels. For
example, the amount of feed that
should be required to maintain a 1200
pound bull in XYZ weather conditions
gaining 3 pounds a day is determined.
Then using the GrowSafe system the
amount of feed actually consumed by
that animal is calculated. If, in the case
of the bull, he consumed less feed than
should have been required for his
performance levels then he will have a
negative RFI which means he was
more efficient. Conversely, if a bull ate
more than should have been required,
he would have a positive RFI which
translates into a less efficient animal.
The average bull would have an RFI of
0.
There are only a limited number of
GrowSafe systems currently available
in the United States on a commercial
basis, with most of them being at
central test stations. The GrowSafe
system consists of individual feed tubs
next to one another at a bunk line. The
feed tubs have weigh bars underneath
them. As an animal comes to the bunk
and puts his head down to feed, his
EID (electronic identification device) is
read by a
sensor and
his feeding
data is
recorded
(i.e. how
long he ate
and how
much he
consumed).
Feeding
data is
transmitted
to the main
system
e v e r y
second.
The most
Bulls on test at the Midland Bull Test, Columbus, Mont., eat from GrowSafe’s
bunk system, which measures each individual animal’s residual feed intake
(RFI).
significant advantage of the GrowSafe opportunity to enhance efficiency. The
system is that feeding behaviors are not key, however, is to identify cattle that
altered. The ability to precisely measure are more efficient. Traditionally, feed
the amount of feed an individual animal conversion ratios provided a measure
consumes is not new. Researchers have of efficiency. However, highly
relied on Callan gates for decades, but correlated to feed conversion ratios is
the difference with the Callan gate is increased growth rates, increased total
that each bull had his own individual feed intake and increased mature size.
feed bunk which could only be The increased mature size also means
“unlocked” by him. Therefore the an increase in maintenance
competitiveness and aggressiveness of requirements, and thus while cattle in
feeding was compromised, as was the the feedlot may convert efficiently, and
data. From the Callan gate, producers grow rapidly, the cows in the pasture
moved to measuring pen efficiency by are bigger and require more feed and
feeding sire groups together and thus “total system efficiency” is not
calculating a feed efficiency for the achieved.
entire pen. While this provided some RFI, on the other hand, is a “clean”
useful data, the GrowSafe system is trait, meaning it can be selected for
marked improvement as now not only without any currently known genetic
can accurate individual feed efficiencies antagonisms. In other words, selection
be calculated but perhaps more for RFI allows one to select the cattle
importantly the RFI of the animal as that achieve desired performance levels
well.
with less feed intake than expected or
Approximately 70 percent of variable normally required.
cost for beef production is feed costs. RFI allows selection for improved
As such, feed costs provide an (continued on page 8)
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(continued from page 4)
now that there is a test; and 2.) if breeders
continue NOT testing and eliminating
carrier animals the problem will persist
forever.
Of course there are many breeders
waiting for lists from the AHA of either
IE-free or IE-carrier animals so they
can make informed breeding decisions.
In checking the Angus Association’s
website I see they list both carriers and
tested non-carriers of certain genetic
defects and also are clear about stating
whether or not a defect is lethal or cosmetic.
I have a feeling we might be
waiting for such lists for quite some
time. Hopefully I’m wrong! I think if a
breeder has gone to the trouble of testing,
those results should be made known
whether on the pedigree or on a list.
The AHA board has some big decisions
to make and hopefully they don’t have
blinders on. The future of our breed really
depends on it.
I will say this again and hopefully
people are paying attention, we have the
tools available now in the form of DNA
tests, let’s use them and make informed
decisions. How many of you have
checked out the Genetic Defects portion
of the Angus site lately? Did you
notice they are listing bulls that carry
the dwarfism gene? Yes, dwarfism. How
many of you thought that problem was
erradicated about 40 years ago? Well it
wasn’t. Of course 40 years ago we
didn’t have DNA tests at all only the
tool of eliminating suspected lines. Evidently
it wasn’t eliminated. Today we
have DNA tests for several genetic abnormalities
and there will be more tests
in the years to come. As a producer of
seedstock genetics why would you not
use these tests? I know there are a number
of Hereford breeders who are testing
and eliminating carriers of both dilutor
and epilepsy. I commend you for
being responsible breeders. For those
of you who are not taking these steps I
ask, why would you not? Do you want
to still have these gentic problems
around in another 40 or 50 years or indefinitely?
— JBH