10
Nutrition & Health: Beef
Feedstuffs, March 16, 2015
Corn particle size will
March 16, 2015.indd 10
Research
with
TIM LUNDEEN
performance.
In addition to studying the average particle size, fecal samples from
the finishing lots were also studied
to determine how much of the grain
was not digested. The more starch
was left in the feces, the less starch
the animal actually got out of the
grain.
Data collected from 34 feedlots in
Kansas, Nebraska, South Dakota, Minnesota, Colorado and Iowa showed an
average particle size of 4,300 microns,
which means the average particle size
had a diameter of 4.3 mm.
“We would call that somewhat
coarse, and yet that turned out to be
the average of our entire industry,” Reinhardt said. “So, the industry, on average, is processing corn to a coarse
particle size.”
He said the diet samples not only
helped determine the average particle
size but also were used to examine the
spread of particle sizes. While the average particle size was just more than
4,000 microns, many samples had
large and fine particles in the mix.
“Two of the feedlots used not dry
rolling but dry hammer milling, which
creates a much finer, smaller particle
size and also a large amount of the fine
Photo: Jupiterimages/liquidlibrary/Thinkstock.
T
HE representative particle size
of ground corn used in diets for
feedlot cattle varies from “fine”
to “medium” to “coarse,” depending
on the preference of the individual
feedlot operator.
Although there isn’t a standard in
place to determine what rates as finely ground corn compared to medium
or coarsely ground, corn particle size
can affect digestibility and how cattle
efficiently use the grain for energy and
growth.
“There is a strong relationship between smaller particle size and increased digestibility of the starch”
from the grain, according to Chris
Reinhardt, feedlot specialist for Kansas State University Research & Extension. “Regardless of what kind of
grain, we feed it for the starch component. The more starch we can get digested (by the cow), whether that be
in the rumen or downstream from the
rumen, it improves the return on the
investment in that grain.”
In a recently completed study, Reinhardt sought to find the average corn
particle size Midwest feedlots use in
finishing cattle diets. The idea was to
learn about which practices are common in feedlots that do not use steamflaked corn but instead use a form of
dry processing for corn, such as dry
rolling or hammer milling.
Although corn prices are cheaper
now compared to recent years, Reinhardt said feedlots should still consider how particle size could affect cattle
PARTICLE SIZE: Corn particle size can vary from fine to medium to coarse,
which has an effect on digestibility and how cattle efficiently use the grain for
energy and growth.
particles,” Reinhardt said.
Based on the survey, Reinhardt
said he believes most feedlots that
use the dry rolling method could
crack their corn to a smaller particle
size to improve grain digestion in
cattle. The key is to work together
with a nutritionist and veterinarian
3/12/2015 11:12:40 AM