Feeding Cows 101
The grass in Montana is some of the best in the world.
Cattle grow quickly through the summer, and gains are cheap.
In fact, the whole romantic idea of cowboys and cattle
drives began with trailing herds of cattle up from Texas
into the rich prairie grasslands to fatten through the
summer before being shipped by rail to markets in the east.
In those early years, cows were rarely fed in the winter.
So why is feeding standard practice now? Charlie Russell's
painting "Last of the 5000" shows one consequence of a hard
winter. And it has been well-demonstrated that the cost of
feeding cattle is very cost-effective for increasing
production of calves.
In the winter, the feed value of the grasses falls off,
and snow can cover it over. So current practice is to cut
and bale excess summer forage, for use in winter when feed
is of lower quality and in short supply.
Ranch cattle in Montana are generally fed through the
winter by daily throwing hay on the ground for them to
consume. From a distance it may seem like another mindless
task performed by a dumb cowboy, but an effective feed
program takes more brainpower than most people understand.
There are a number of considerations in feeding a cow,
and the first is when do you feed cows?
The answer to that question is whenever they are no
longer getting enough grass to supply their nutritive
requirements. If there is adequate winter grass, a cow may
go all winter with just a protein and energy supplement. But
the grass may be depleted, snow may cover it up, or weather
may get so severe that the cows can't eat the grass fast
enough to keep up with their energy requirements.
In stormy weather the cows may choose to stay in the
shelter of brush rather than to expose themselves to the
elements for a paltry feed of sparse grass. They will come
out for hay, however.
The next question is how much do you feed them? The
simple answer is - all that they can eat. You've given them
just the right amount if they consume two-thirds of your
offering before going for water, then clean up all but the
spoiled or most course of the hay by day's end. But a more
complete answer takes in a number of factors: weight of the
animals, objectives of the task, available forage, and
The place to start is with the maintenance requirement of
the cow - about 2% of her weight per day. But a cow may be a
little underweight after giving milk to her calf all summer,
and we hope she has another calf growing inside of her. So
if she is thin, she may need to add weight as the fetus
develops - about 100# of gain before she calves.
So, a 1200# cow needs roughly 24# per day of hay to
maintain her weight, plus another 750# of feed over the next
3 months to compensate for the fetal growth - an additional
8# of hay per day.
Cows starting the winter in good condition may be fed to
simply maintain their weight - and since the calf is growing
inside, a static cow weight will result in a loss of
condition on the cow. The cow will likely regain that weight
when she hits green grass, so many ranches feed to merely
maintain cow weight through the winter.
What do we feed them? If hay is of decent quality, most
of the cow's protein and energy requirements are provided
hay, and no supplements are necessary. If plenty of grass is
available, hay may not be needed. But the dry, brown grass
available in the winter does not have the nutrition
necessary to maintain a cow and grow the calf in her womb. A
liquid feed supplement or a couple of pounds of barley-cake
a day will be necessary to bring protein and energy levels
Hay comes in a wide range of quality. Straight grass hay
may be 8-10% protein and 60-70% Net Energy. Earlier in
gestation this may be adequate for her nutritive
requirements. As the fetus grows, those requirements
increase. Alfalfa/grass hay may be 10-15% protein and 70-80%
net energy. After calving a cow needs better hay. Straight
alfalfa may be15-20% protein.
Now throw in weather. Since Montana cattle mostly winter
out in the open, they are subject to a range of temperatures
and conditions. As the temperature drops below freezing, a
cow burns more and more fuel just to obtain the calories
necessary to maintain body heat. At 20o below she may eat
half again more feed - just to keep warm!
With her maintenance nutrition supplied by that 24# of
green hay - or by dry grass and cake - a cow only needs
additional roughage to generate heat. In fact, poor quality
roughage actually gives off more heat of digestion and goes
further towards keeping a cow warm. So in cold weather,
straw is not only cheaper than hay, but better for keeping
her warm. And the cows can bed down on whatever don't eat!
Studies have shown that bedding on straw in cold weather can
reduce feed requirements by 15%.
This weather factor is a serious component. If the heat
that is drawn off by snow, wind, and freezing cold isn't
made up by additional feed, it will be made up by pulling
reserves from the cow's body - depleting fat stores, then
muscle. Unless there are copious amounts of available grass,
cows need extra feed on those colder days. I've seen where
cows have eaten willow shoots as big as a pencil, trying
desperately to consume enough roughage to keep them warm.
Only in a feedlot is it effective to feed cattle the same
ration day after day. These cattle are given a belly full of
a carefully calculated ration designed to achieve a precise
rate of gain. They are already receiving all the feed they
can consume, so they have both the intake and the reserves
to withstand a bout of severe weather. The consequence of
maintaining that same ration through cold weather, however,
is a drop in their rate of gain.
Another question is where to feed the cows. This again,
is subject to weather. On a cold, calm day they can be fed
anywhere. When the wind is blowing they need to be fed where
there is some shelter from the wind - along the tree-lined
river, in a swale or coulee, behind a hill, or next to the
If the ground is wet and muddy they should be fed on a
sidehill, on a rocky knoll, in a place where the sod is
unbroken, or early in the morning before the sun thaws the
The cows will spend time on the feed-ground, and they
will leave plenty of manure as evidence. It is best to move
the feed-ground every day, to both provide a clean "table"
for the cow's feed, and to distribute the fertilizer more
evenly over the field. Wind and snow will limit your access
to some parts of the field at times during the winter, so
it's best to take advantage of nicer days to spread the hay
- and the manure - further from the haystack whenever
And when do we quit feeding hay? When the cows stop
eating the hay we are offering.
The new grass coming up in the spring is like candy for
those cows. It is bright green, tender, and juicy. After a
winter of dry hay, they are eager to get out and partake of
that lush green growth. And the rancher is as tired of
feeding that hay as the cow is of eating it.
But that new grass is short, and it's hard to get a belly
full. It is mostly water. And it is fragile - the new grass
is growing from root reserves that are easily depleted by
early grazing. As tempting as it is to just turn the cows
out, it is very poor practice.
Nutritive requirements for the cow are at their highest
at the time right after calving and just before breeding.
For most ranches that peak of nutritive requirements
coincides with the first flush of green grass. And that
first flush of green grass is the period when it can least
withstand the pressure of grazing.
It is for this time that a rancher saves his best hay -
second or third cutting alfalfa. Properly baled, this
regrowth hay is rich, green, fine-stemmed, and tasty. It can
have protein well in excess of 20%, and net energy
approaching 90%. Second cutting alfalfa can entice those
cows to eat hay for another couple of weeks - long enough
for the new grass to grow up tall enough to sustain the
cows, and to sustain itself.
Now I hope you can see that feeding cows isn't a simple
as dumping hay on the ground. It is an art that is based on
science. Anyone can do it, but it takes some thought and
understanding to do it well.
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