MINERALS FOR
DEER
This article was originally printed
in the June / July 2000 issue of Tracking The Industry. .
.
When talking with deer producers about
feeding their deer, questions inevitably turn to mineral and vitamin
supplementation. Should the diet be adjusted throughout the year? What are the
daily requirements? What supplements should I be using? Is my supplement
meeting the daily requirements? What are some signs of deficiency and toxicity?
Why are some minerals listed as percentages and others listed as parts per
million or milligram per kilogram? While the easiest method in feeding minerals
to deer is simply to buy a supplement and feed it at the recommended levels, I
will try and address several of these questions in this article.
The main complicating factor when feeding
white-tailed deer is their changing daily intake levels from winter to autumn.
White-tailed deer dry matter intakes range from 1.8% of body weight in mid
winter to 2.8% in the summer and autumn. While this difference in dry matter
intake is due to several factors, one key result is a shift in the metabolic
rate of the deer. White-tailed deer have a high metabolic rate in the late
spring and fall and low metabolic rate in the winter. How this may affect daily
mineral requirements has yet to be determined, and at this time, only subtle
changes to accommodate age sex and stage of production have been incorporated
into deer mineral requirements tables (Table1).
So let's discuss the minerals themselves
that are required. Minerals that are required by deer are split up into two
groups, macro and micro minerals. Macro minerals required by deer include
calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), chlorine (Cl),
potassium (K) and sulfur (S). These minerals are measured as a percentage of
the diet. Micro minerals required by deer include cobalt (Co), copper (Cu),
iodine (I), iron (Fe), magnesium (Mc), molybdenum (Mo), selenium (Se) and zinc
(Zn). These minerals are measured by parts per million (ppm) or milligrams per
kilogram (mg/kg) of feed. The difference between the macro and micro minerals
is that macro minerals are usually required by the animal in grams or kilograms
per day, while micro minerals are required in milligrams per day.
Table 2 and
Table 3 show a list of macro
and micro minerals what their functions are, and some common deficiency /
toxicity symptoms.
When trying to determine whether or not the
mineral supplement is meeting daily requirements, it is easiest to evaluate the
ration on a unit basis. A unit can be 1 kilogram, 1 pound, 1,000 kg. A mix mill
batch, etc. Evaluating a ration on a unit basis eliminates the confusion
associated with changes in daily feed intake. For argument sake, I will use 100
kilograms as a unit for this example. So let's suppose that the daily
requirements for an adult white-tailed deer in the winter is 0.50% calcium and
25 milligrams per kilograms (mg /kg or ppm) of copper (dry matter
requirements). The ration is composed of alfalfa hay, oats and a supplement
(Note: Be aware that when evaluating/formulating any ration, it is necessary to
include all feed ingredients as each ingredient offers different levels of
minerals. Alfalfa, for example is high in calcium yet only contains relative
levels of phosphorus, while cereal grains such as oats and barley are nearly
deficient in calcium while containing adequate levels of phosphorus. Also, all
calculations using different ingredients should be on a dry matter basis.) In a
100 kilogram unit, the ration should be balanced to contain 0.50 kilograms of
calcium (100kg x 0.50%) and 2,500 milligrams of copper (100kg x 25 mg/kg) in
the feed dry matter. By formulating/evaluating a ration in this manner it does
not matter if the deer eats 1 kilogram or 3 kilograms of the ration, it will
consistently receive 0.50% calcium and 25 mg/kg of copper as required. This
method of formulating/evaluating also removes the extra mathematics that can
create simple errors and confusion when developing a feeding program. The
actual mechanics of feed formulation are too involved for the time and space
permitted in this article and should be discussed separately another
day.
In
conclusion, the main purpose in feeding mineral supplements is to ensure
adequate mineral levels in the diet as basic feed ingredients such as alfalfa
and oats "usually" contain inadequate levels of mineral to meet daily
requirements. While cereal grains are relatively consistent in the mineral
level, it is necessary to conduct a feed analysis on forages as their mineral
levels are less consistent. Keep in mind that a balanced feed ration is
balanced for energy first, protein second, calcium and phosphorus third,
followed by the remaining macro and micro minerals and vitamins. While mineral
supplementation is extremely important, it is more important to ensure that the
basics (energy, protein, calcium, phosphorus) are met first, otherwise animal
health and production levels will most likely suffer.
Murray Feist
- Livestock
Nutrition Specialist Sask. Ag. & Food
Ensminger, M.E., Oldfield, J.E. and
Heinemann, W.W. 1990.
Feeds and Nutrition. 2nd Edition.
Ensminger
Publishing Company, Clovis, California, 93612
Feist, M.F.
1998.
Evaluation and development of specialized
livestock diets in Saskatchewan.
M.Sc. dissertation.
University of Saskatchewan, Saskatoon, Saskatchewan. 154pp.
Haigh, J.C. and Hudson. R.J. 1993.
Farming wapiti and red deer.
Mosby Year
Book Inc. St. Louis, Missouri.
Underwood, E.J.
1981.
The mineral nutrition of livestock. 2nd
ed.
Commonwealth Agricultural Bureaux, Slough,
England.
Varner, L. 1998.
Purina Mills, Inc.
Gonzalez, Texas.
-
Back to Library -
Please report any technical
problems with this site to the webmaster