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by Dr. Matt Poore
Byproduct commodities have become a popular
source of feed for growing weaned calves throughout the southeastern
US. Byproduct feeding programs vary from simple programs using a
single commodity such as soybean hulls, to very complex programs
utilizing five or more commodities in mixtures.
Research has been conducted in North Carolina
and elsewhere around the US to determine how to optimally incorporate
byproducts into feeding programs, and a lot has been learned. However,
there still is a lot to learn, especially concerning how to predict
the feeding value of the complex mixtures of byproducts, and how
the single byproducts work in more creative feeding programs (such
as self-feeding).
Major byproducts available
There are a wide variety of byproducts available to use for cattle
feed, but usually those with a high level of local production will
be the best values. Products such as cookie meal and hominy feed
do make really nice ingredients, but they often have high freight
charge that make them generally useful only in specific situations.
In the Carolinas the most widely available
products include soybean hulls, corn gluten feed (wet and dry),
wheat middlings and whole cottonseed.
Soybean hulls (sometimes called just soyhulls)
are the seedcoat of the soybean that is removed when they are processed
to extract oil and produce soybean meal. There are plants all across
the south that process soybeans so soybean hulls are widely available.
They contain about 14% crude protein and about 80% TDN, and are
high in fiber. The fiber in soybean hulls, like many of these byproducts,
is very digestible and produces a desirable fermentation in the
rumen which makes them a very good supplement for high forage diets.
Major mineral levels are also well balanced in soybean hulls which
is an advantage over many other byproducts. Soybean hulls have worked
out very well for a wide variety of calf-feeding programs.
Corn gluten feed is the byproduct of wet corn
milling. Corn gluten feed contains the corn bran, and the soluble
components that come from steeping the corn grain at the start of
the milling process. It is available either wet (with about 38%
dry matter) or dry. Crude protein level runs about 20% and the TDN
level is about 80%, with the wet generally being a little lower
in protein and higher in energy than the dry. Corn gluten feed contains
a high level of phosphorus and sulfur and those are items you need
to consider when developing a feeding program with it. Corn gluten
feed has been widely used and makes a very good option for calf-feeding
programs.
Wheat middlings (or just midds) are a byproduct
of flour production and are available anywhere flour is produced.
They tend to be “hot” compared to some of the other
byproducts and you have to be a little careful when you use them.
Wheat middlings contain about 16% protein and 80% TDN, and are widely
used in the feed manufacturing business. This is because they have
a reasonable good nutritional value and really make for a good quality
pellet. They are most easily handled in pellet form, and we have
a number of flour mills that have them available. Midds contain
a high level of phosphorus and love calcium, and sometimes, a mill
will add limestone to them before pelleting, which improves their
value as a supplement.
Whole fuzzy cottonseed is widely available
across the South, and is probably the most convenient byproduct
for producers to purchase (where there are local gins), because
often gins will work with customers to sell any quantity in bulk
(within reason). Cottonseed contains about 23% protein and 96% TDN,
which gives it the highest nutrient content of the locally available
byproducts. The unique thing about cottonseed is that it is easy
to store and handle; it keeps for a long time as long as you keep
it dry, and it requires no processing. The problem with whole cottonseed
is that is does not make a very good feed for calves. For example,
if you exceed about .33% of their body weight (2 lbs for a 6 cwt
calf), generally they will need more supplemental feed then that
to perform at the level you would like them to. Cottonseed is the
ideal supplement for brood cows, and that is probably where it is
most useful. However, farms that already have it on hand for cows
might also want to use it to supplement the calves too, along with
some other source of concentrate.
Coming…Reasearch with soybean
hulls, corn gluten feed and wheat midds.
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