Using Urea and Anhydrous
on Corn Silage
When treated silage is fed to ruminant animals it provides a good
source of soluble nitrogen. This nitrogen is then used by the animals
first stomach to synthesize microbial protein which the animal can
use for growth and production.
Nitrogen makes up approximately 16% of the average feed protein,
so one kilo of nitrogen from urea or anhydrous can provide the means
for the animal's rumen to make 6.25 kilos of protein.
Urea is 45% nitrogen, anhydrous ammonia is 82% nitrogen. Only small
amounts of these compounds are needed to dramatically increase the
nitrogen content of the silage. By adding 10 lbs of urea to 2000
lbs corn silage at 30% dry matter will increase the crude protein
by approx. 3%. Similarly 6 to 6.5 lbs of anhydrous will do the same
- the finer the chop the better preserving quality of the silage
- products increase bunk life, may improve intakes
- dry silage a problem, has to be less than 40% dry matter preferably
less than 33% dry matter
- anhydrous takes specialized equipment, Cold flow unit to liquefy
ammonia and accurate flow meter to measure application rates.
- both products are most easily dealt with in a bunker silo storage
- hot spots or areas where uneven distribution has occurred are
common when urea has been applied. Urea should be applied with
a dry innoculant applicator to ensure even distribution.
- pure urea is poisonous to livestock, many times cattle have
been poisoned by getting into a bag of urea.
- anhydrous ammonia is potentially very dangerous should the delivery
system develops a leak. Severe burns and lung damage could result.
- silage run-off from nitrogen treated silos is much more potentially
dangerous to water courses. Applying nitrogen to very wet corn
silage should be avoided.
- feed grade urea should be used to ensure quality assurance.
- when using these nitrogen products, producers should check and
double check their estimates of silage volume and the amount of
product applied. Anhydrous ammonia nurse tanks should be weighed
before and after application to verify the amount of product that
disappeared or was used in application.
- at present these products are very attractive from both price
and from feed utilization view.