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Can
I feed whole shell corn to my ruminants?
1/21/2008
Michael Fisher
Area Extension Agent
(Livestock)
Colorado State University Extension
Golden Plains
Area |
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Recently, I was one of the invited speakers for a feedlot
management program. The topic that I was asked to discuss was feed ingredient
maintenance. Here is a topic that is referred to often and a lot of people have
ideas about it; however, scientific evidence on appropriate ingredient
maintenance can be scant. Mostly, we take the whole subject for
granted.
While conducting my literature review on the subject, I was
interrupted by a phone call from an old friend who opened the phone
conversation with, "Fisher, what are you doing?" My response was, "Researching
the pros and cons of feeding whole corn vs. cracked corn." To which my friend
immediately followed with, "Well, you can forget about the whole corn. Even
Jimmy knew to crack corn."
Of course, my friend was referring to "Blue
Tail Fly", a slave song credited to Daniel Emmet in the mid-1840's. More
specifically, he was referring to the line of the chorus that gets repeated
over and over again, "Jimmy crack corn and I don't care." Historians have
several ideas of what Jimmy may have been doing when he crack corn; ranging
from opening a jug of corn liquor to being whipped. Yet, none of these support
my friend's theory that Jimmy was grinding feed.
Let's take a couple of
minutes and play devil's advocate to my friend's opinion that corn must be
cracked before we feed it.
Whole shell corn can be fed as an unprocessed
product. In fact, there are some researchers who believe that when cattle are
on extremely high concentrate diets (less than 20% roughage) the whole shell
corn diet can have slight advantages over cracked corn. One obvious advantage
is that we can save the cost of processing when we feed corn as a whole kernel.
Another advantage is that whole shell corn can be utilized as "scratch factor",
which is usually associated with roughages. The rumen is lined with thousands
of small, finger-like, structures called papillae. The papillae absorb volatile
fatty acids (VFA's) that are given off as byproduct when the rumen's microbial
population breaks down the feedstuffs that the animal consumes. These VFA's are
essential to the ruminant animal's nutrition and survival. The papillae require
some kind of scratching action to grow and remain healthy. Theoretically, the
better the scratch, the better the VFA's are absorbed, and the better the
animal's performance.
As ruminants chew corn, they will break open the
bran of some of the kernels and swallow others whole. Some of the kernels will
receive further breakage when the animal chews its cud. However, many of the
kernels will remain a whole kernel. This creates a harder job for the microbial
population. They have to get through the bran to enter the kernel and digest
the starch from inside. By having lots of unbroken kernels in the rumen,
digestion and utilization is slowed. While this may lessen the chance of
acidosis, bloat, or liver abscesses; it may also lessen performance and will
reduce both dry matter intake and feed conversions. This problem can be
amplified when animals are hungry or there is a lot of competition for space at
the feed bunk. These hungrier and more competitive animals are prone to gulping
the shell corn without chewing much of it.
Many producers who have fed
whole shell corn have complained of the number of whole kernels that are
excreted in the manure. Canadian researchers examined this and determined that
11 percent of the kernels that appeared to be whole in the feces were actually
hollow. It would seem that the microbial population was able to find entry
through the bran layer and digest the internal starch of the corn. Another
research study in Ohio ascertained the number of corn kernels that were fed to
cattle and compared this to the number excreted. Further analysis determined
how many excreted kernels where hollow versus starch filled. These researchers
determined that 88 percent of the whole shell corn that was fed was utilized by
the animal.
One of the places that we see whole shell corn as being
successful is when fed to cattle on a self-feeder system. A supplement pellet
is mixed with the whole shell corn and placed in the self-feeder. The feed flow
doors are set at a narrow flow so as to have a consistent stockpile of corn and
supplement pellets present in the bunk without an overflow. Assuming that the
producer has not overstocked the lot, this should limit competition and feed
gulping. While 5 to 10 inches of bunk space per head is recommended for the
self-feeder, some have shown this technique to be successful down to 3 inches
of bunk space per head.
If you are going to feed whole shell corn, there
are a couple of other cautions that you should be aware of. Small feed
ingredients, such as salt and mineral do not mix well with whole shell corn.
The small particles will sift through the feed and work their way to the
bottom. These should be fed separately and at free choice.
Also,
extremely dry or "flinty" corn requires some attention before feeding. Whole
shell corn works best at 13 to 15 percent moisture. When it is at 12 percent
moisture or less you should consider either processing or moistening it. By
adding 3 to 5 percent water to the corn, while mixing it, we can help to
increase the moisture level. Some producers will use a mixture of water and
surfactant. The surfactant dissolves the outer, wax-like layer of the grain,
allowing it to absorb moisture.
Under proper management, whole shell
corn can be utilized as an effective feed source for ruminant animals. If you
wish to discuss this subject further, Michael Fisher can be reached through the
Yuma County Extension office at 970-332-4151 or by e-mail at
mj.fisher@colostate.edu. |
Page Created and Maintained by: Perry D. Brewer, Area
Extension Agent (Technology Education/Youth)
1/21/2008 |
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