Page 26 - MWC 10-26-2023s

The Midwest Cattleman · October 26, 2023 · P26
UNDERSTANDING CATTLE HEALTH CONCERNS ON CORNSTALKS
Awareness and planning important when grazing cornstalks.

By Lindsay Waechter-Mead, DVM, University of Nebraska Extension

Grazing corn residue is epithelium. This leads to an Photo - Troy Walz
common practice in the Mid- increase in acid-loving bacte-
west and a quality resource ria and yeast in the damaged
for cattle producers to utilize. rumen. All of these affect the
While the forages available blood volume and hydration
can provide the necessary status of tissues throughout
nutritional requirements, the body, leading to acute
there are a few health condi- clinical signs of diarrhea, de-
tions that need to be planned hydration, depression, and
for prior to turn out. anorexia.
Treatment for acidosis in-
Acidosis volves restoring the rumen
Acidosis, or grain overload, microbes, correcting dehy-
occurs when cattle consume dration, and acidic rumen
large amounts of feed that microenvironment, and man-
contains high quantities of aging secondary complica-
fermentable carbohydrates, tions. Long term consequenc-
leading to clinical signs in es of acidosis may include
the animal. When grazing abortions and laminitis.
corn residue, the feedstuff Management is key to
would be too much dropped preventing acidosis and is of corn in three different 100 tremors and sudden death.
corn. Rumen microbes rapid- more rewarding than treat- feet rows and dividing this Abortions may occur 10-14
ly begin to ferment the carbo- ment. Knowing how much number by 2. If too much days after ingestion of high
hydrates in the corn, which corn is in the field will help dropped corn is a concern, nitrites due to lack of oxygen
leads to an increase in lac- establish a grazing plan. The rumen microbes can begin to fetus.
tate formation. When lactate risk of acidosis increas- acclimating to increased car- Knowing the nitrate lev-
production increases, the es if fields contain more bohydrate diets by slowly in- els of plants intended as
rumen pH drops below the than 8 bushels of corn per creasing amount of corn fed feed is vital information in
normal range of 5.6-6.9 and acre. Bushels can be estimat- over a 10-day period prior to establishing a prevention
begins to damage the rumen ed by counting dropped ears grazing. plan. Nitrate samples can
be taken from both stand-
Nitrate toxicity ing plants and baled forages.
Nitrates accumulate in Forages with >10,000 ppm
plants when uptake by the nitrate (NO3-) may lead to
roots exceeds the rate of con- acute toxicity signs and sud-
version to protein, such as den death. Levels over 5,000
during episodes of drought ppm (NO3-) should not be fed
and plant stress. When a ru- to pregnant animals due to
minant consumes high-ni- the increased risk of abortion
trate plants, the rumen mi- and stillbirth.
crobes convert the nitrate to Any health concerns
nitrite. Excess nitrite is ab- should be discussed with
sorbed into the bloodstream, your veterinarian to estab-
where it changes the oxygen lish proper prevention and
carrying capacity in red blood treatment protocols.
cells by converting hemoglo-
bin to methemoglobin. Met-
hemoglobin is unable to
carry oxygen to tissues in the
body, resulting in asphyxia-
tion. Clinical signs of toxic-
ity include weakness, rapid
breathing, lethargy, muscle