What Stocking Rates Should You Have?
US - A beef cow eats three per cent of her body weight in forage daily. Therefore, a 1,200-pound cow will need 36 pounds of grass per day.
27 October 2010
3 minute read
Those facts are a start for calculating stocking rates of cows per acre.
"My most frequently asked question is, 'How many cows should I have?'" says Rob Kallenbach, University of Missouri Extension forage specialist.
"How many cows? That's the last question in a series of questions to determine stocking rate," Mr Kallenbach says.
The answer depends on whether the farm is located in north Missouri or the Ozarks. The type of soil, fertility and forage species affect the pounds of dry matter available per acre.
Also, cow size is important. A 1,500-pound cow needs 50 per cent more forage per day than a 1,000-pound cow. Many questions must be answered to determine "How many cows?"
Mr Kallenbach will talk about variables affecting stocking rate at the Missouri Forage and Grassland Conference, November 8-9, at Lake Ozark. His topic is "Matching Stocking Rate to Forage Growth."
There is no more important question in determining the success of a grass farm than the stocking rate, Mr Kallenbach says. Investment in land and cattle must be balanced for best profit potential.
With the correct stocking rate, producing the optimum pounds of beef per acre will help the bottom line.
Rules of thumb can be used to determine production and stocking rates.
A farm with good pasture, not great pasture, may grow 3 tons of forage per acre on an annual basis. That lightweight cow will need 5 tons of forage. But if the cow has a calf, as expected, that will increase the forage demand to raise the calf for six months to 7.5 tons.
That shows a need for 2.5 acres per cow-calf pair. But wait, Kallenbach says. That assumes the cattle are totally efficient in harvesting forage, wasting none.
"Cows are never 100 per cent efficient," Mr Kallenbach says. "Really good operations get 70 per cent efficiency. Much more common is 40 per cent consumption."
The calculations go on. Different equations will be needed for dairy cows, stocker calves and other types of livestock.
"If there is any one thing we've learned about stocking rates it's that management-intensive grazing (MiG) pays," Mr Kallenbach says. "Controlled grazing using hot-wire paddocks to subdivide pastures can double grazing efficiency."
A side benefit of MiG is that more tonnage of higher-quality forage results from proper management. Alternating grazing with resting allows more forage growth.
Also, managers will learn the need for measurements for efficient production. That includes measuring forage growth and weighing calves. Actual measurements rather than rules of thumb help gain extra profits from grasslands.
"Our best producers are using rising-plate meters to estimate the dry-matter content in each grazing paddock," Mr Kallenbach says. "Measurements guide actual stocking rates."
After all calculations are done, Kallenbach advises stocking at about 90 per cent. That leaves a safety margin for a dry spell.
To put his 45-minute talk into perspective, Mr Kallenbach tells how much there is to learn. "A forthcoming book on grazing by MU Professor Jerry Nelson devotes 160 pages to telling research results on stocking rates."
