World Grain - December 2023 - 44

FEED QUARTERLY OPERATIONS
tions like damaged kernels, odor, bug infestation, and foreign
material, and analytical observations like moisture, test weight,
and mycotoxin concentration.
The determination of the moisture content of grain is important
for making decisions pertaining to storage, shrinkage, and
other feed milling processes. Moisture analysis
of whole grain ingredients should be done
for every incoming load due to the effects
that added moisture can have
throughout the feed manufacturing
process. Options for rapid
analysis of moisture include
using a Dickey-John moisture
analyzer or near-infrared spectrometry
(NIRS). Test weight
per bushel can be determined
using an electronic apparatus
outlined by the Approved Equipment
Handbook by the USDA Federal
Grain Inspection Service.
Mycotoxins are one of the major quality concerns
for cereal grains. Mycotoxins can be produced in the field
or in storage. Field toxins include deoxynivalenol (vomitoxin),
zearalenone, and fumonisin and storage toxins include aflatoxin
and ochratoxin. To determine the risk of mycotoxin contamination
from grains, weekly reports are available to assess the risk of
mycotoxin contamination in grains from specific areas that can
help determine how many loads to sample.
Clearly defining quality assurance
goals and providing resources to
achieve these goals is key to a
successful quality program.
Lateral flow test strips or enzyme-linked immunoassay (ELISA)
kits are commercially available and can be used as a single
mycotoxin test to determine the toxin level present in grains and
byproduct ingredients. However, it is important to note that each
type of mycotoxin requires a specific test. The FDA has published
guidance levels for vomitoxin and fumonisin and has published
regulations and compliance policy for aflatoxin.
Particle size reduction of cereal grains
Cereal grains are ground to improve mixability and bulk density
and increase nutrient digestibility by breaking the hard, protective
outer layer of the grain. Concentrated nutrients in the endosperm
and germ become more available as the surface area
to volume ratio increases, allowing more access for digestive
enzymes.
Factors that influence subsequent particle size of grains include
grain growing conditions, grain moisture, mill type and
settings, and mill maintenance. Therefore, measuring particle
size becomes a critical step in quality feed manufacturing.
44
There are many factors that influence subsequent particle size
and manipulation of any can produce a variety of particle sizes.
For a complete particle size analysis both geometric mean diameter
dgw
and geometric standard deviation Sgw
must be evaluated.
Using the same particle size testing method (3-sieve or 13-sieve
stack) is important to remain consistent to compare results to
previous particle sizes and observe changes when manipulating
equipment and equipment wear.
For a detailed description of testing procedures, see " MF3342
Evaluating Particle Size of Feedstuffs - Kansas State University. "
Batching
and mixing
Nutritionists formulate diets based on the assumption that the
animal will receive all the nutrients needed for maintenance and
growth each time they go to the feeder. Batching and mixing
are the two major factors that influence ingredient/nutrient addition
and distribution in feed. How ingredients are stored after
receiving, order of ingredient addition to mixer, scale accuracy,
ingredient characteristics, mixer type, and mixing time all play an
integral role in final feed quality.
Collecting system data over time can be a management tool
used to create change and maintain processes and equipment. Using
statistical process control (SPC) analysis can help with the
predictability of the batching system.
For precision formulation to be successful, a uniform mix must
be determined by the coefficient of variation (CV). Procedures
for testing mixer uniformity can be found in " MF3393 Testing
Mixer Performance - Kansas State University. "
A mixer uniformity test is often done by using a single source
tracer (i.e. salt, trace minerals, or iron filings) as the indicator. Ten
samples should be pulled in order from mixer discharge or sack
off with a probe and the tracer analyzed to be tested for uniformity.
The CV can be calculated by CV% = (standard deviation/
mean) × 100%. Any changes in mixing should be validated by
mixer uniformity. Mixer uniformity CVs should be done annually,
if not bi-annually, for validation or when there are major
changes in ingredient characteristics or equipment. The feed industry
standard is to achieve a CV of less than 10%.
If results are between 10% and 15%, it is considered a good
mix, and mixing time should be increased by approximately
25%. With results of 15% to 20%, mixer time should be increased
by 50%, and mixer wear and ingredient propriety should
be addressed. Any results greater than 20% are considered poor
and should be evaluated.
Pelleting
Pelleting animal feed provides many benefits from improved palatability
and flowability to decreased feed wastage, reduced ingredient
segregation, and destruction of pathogens. When quality
is maintained, pelleting feed may show benefits with improved
average daily gain and feed efficiency.
There are numerous factors that impact the pelleting process,
including diet formulation, pelleting conditions, and specific pellet
mill components. There are also many processing parameters
December 2023 / World Grain / World-Grain.com
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World Grain - December 2023

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