|
>
Department >
Home >
Beef
>
Beef/Cattle >
Drought & Water
Beef/Cattle Extension Program
Because of the drought, can Vitamin A be deficient
in my cows?
|
"In
addition, some scientists have suggested that
high nitrate forages common in drought years can
exaggerate vitamin A. "
|
By John Paterson, MSU Bee/Cattle
Extension Specialist
Vitamin A is rarely a concern in range cattle nutritional
programs because it is readily synthesized from carotene
that is common in green growing plants. However,
in drought situations were plants become dead or dormant,
the carotene content becomes practically devoid and may
lead to a deficiency of the precursor to vitamin A. Carotene
is very low in mature, weathered forages, grains and many
crop residues. Carotene will be lost in stored hay
crops over extended periods of time. Therefore if
hay that was stored throughout all of last fall and winter
is to be fed in the upcoming winter, the vitamin A content
will be considerably less than when that forage was originally
harvested. In addition, some scientists have suggested
that high nitrate forages common in drought years can
exaggerate vitamin A deficiencies. Deficiencies
of Vitamin A usually show up first as weak, blind or stillborn
calves. Other signs are scours, respiratory problems,
poor gains and poor reproduction. Fortunately,
the liver of cattle is capable of storing vitamin A for
long periods and frequent supplementation is not necessary.
A singular injection of one million International
Units (IU) of vitamin A provides sufficient vitamin for
2 to 4 months in growing and breeding cattle. A
word of caution: Vitamin A and A,D, and E injections
have been found to occasionally cause a severe reaction
to the vaccine. Please consult your veterinarian about
the use of these products.
Because the daily requirements of beef cows range from
30,000 to 50,000 IU, depending on size, stage of production,
and level of milk production, supplements can be fortified
with vitamin A to supply the minimum daily requirement.
Depending on the quantity of range supplement
being provided, vitamin A can be added to supplements
at the rate of 5000 to 10,000 IU per pound of feed.
This information provided by Dr. Glen Selk from Oklahoma
State University.
|
