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Drought Options
Roughage Needs
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Roughage Needed per Cow
(Lbs. Dry Matter / Year)
Cow Weight (lbs)
1,200 1,300 1,400 1,500 1,600
Days 200 2,640 2,860 3,080 3,300 3,520
on 250 3,300 3,575 3,850 4,125 4,400
Feed 300 3,960 4,290 4,620 4,950 5,280
Many producers facing drought are struggling
with securing roughage needs. Roughage supplies
are limited; the question is how little roughage do
we need to secure.
In an average year, a beef cow will consume 2.5%
of her body weight in dry matter intake.
Therefore a 1400 lb beef cow, 7-8 months
pregnant will consume 35 lbs per day of dry
matter, plus moisture and feed waste.
Management through the drought conditions
suggests that we will need to feed less roughage,
and balance accordingly.
Learning from the dairy industry, we know it is
possible to feed higher levels of concentrate, and
still have healthy cow. Concentrate is defined as
grain or pellets or supplement. In an average year
with average feed quality, the dairy industry is
comfortable feeding 50% concentrate: 50%
roughage, on a dry basis.
Given the dry growing condition, forages will not
be average. Based on research from the mid 80's,
alfalfa grown during a dry year will have
significantly lower fiber. This research shows that
full bloom alfalfa grown in a drought will have
similar fiber levels as pre-bloom alfalfa grown in
a normal year. So, if your roughage source this
year is perennial forage, it will be better quality,
and less effective fiber. Therefore, feed testing
and ration balancing will be imperative.
Extrapolating from the dairy industry, beef cow
producers can budget on feeding a ration that has
1% of body weight on a dry basis of concentrate.
This equates to a 1400 lb cow being able to
consume a ration that has as high as 14 lbs of
grain, pellets, or combination thereof per day.
This amount of concentrate should be delivered
twice per day - half in the morning and half
in the afternoon. As well, calcium mineral
supplementation, and the use of ionophores,
must be considered. The remaining 14 plus
pounds must come from a roughage source.
As long as we follow the 7-9-11 rule (7% protein
in mid pregnancy, 9% protein in late pregnancy,
and 11% protein after calving), and energy is
sufficient, the roughage portion can be "filler"...
straw, hay, crop residue, or other high fiber
material. Both Dr Robert Westra and Dr Erasmus
Okine refer to research that shows it is feasible to
include up to 25-30% poplar sawdust, in a
balanced pellet or mixed with silage, as a fiber
source.
Several projects and/or nutritionists suggest that,
providing the ration is balanced in terms of
protein and energy, a cow can be fed at as low as
1.5% of body weight in dry matter intake, rather
than the average 2.5%. Simply put, as long as the
nutrients requirements are met, a cow can be fed
less than her desired intake. Using the same 1400
lb cow, as long as the ration has enough protein,
energy, vitamins and mineral, she would consume
11 lbs of concentrate and 11 lbs of roughage. She
would not have a satisfied appetite, but she would
maintain production.
The following chart summarizes the amount of
roughage beef producers can budget for. The
numbers are based on the assumption of 1% of
body weight coming from concentrate, total intake
is limited to 2.1% of body weight per day on a dry
basis, the feeds are tested, the ration is balanced,
and it is a March calving herd. The chart below is
based on -15 degrees Celsius. Colder
temperatures require modifications. Cows must be
sorted by body condition regularly. You must
check with your nutritionist.
Trevor Yurchak
Beef / Forage Specialist, Athabasca