This year, dry weather during September delayed the planting and emergence of wheat, which will delay turnout of calves. Research indicates that forage intake and animal performance is limited when pastures have below 850-1,000 pounds of forage per acre.
The most success in a small grain forage grazing system is achieved if the start of grazing is delayed until forage is ready and grazing management allows for adequate leaf area for forage regrowth. Overgrazing and starting too early will limit animal performance and reduce the total overall production of these pastures.
Rains and mild fall temperatures during October helped get pastures back on track. If pastures are below this level, turnout may need to be delayed until pastures are ready.
• Wheat forage grows at 3-3.5 lbs. of forage dry matter (DM) per acre for each growing degree day.
• A growing degree day is the average daily temperature: 40 F.
• If, on a given day, the high temperature is 65 F and the low temperature is 45 F, the average daily temperature is 55, so there are 15 growing degree days.
• Wheat would be expected to produce 45-52 lbs. of forage DM that day.
• So, 10 extra days of growth would be needed to get a pasture from 400 lbs. of forage an acre to 850 lbs. of forage an acre if these temperatures persist.
Setting stocking rates on wheat pastures in the fall and winter has large impacts on performance of growing calves and can have large influences on the productivity of pastures during the spring. Forage production and steer performance from 10 years of experiments were used to determine the response of average daily gain (ADG) to initial forage allowance (lb. initial forage DM/lb. initial body weight) on ADG during the fall and winter.
The maximum ADG of 2.7 lbs./day could be expected at 5 lbs. forage DM/lb. initial calf bodyweight, and ADG of 2 lbs./day could be expected at an initial forage allowance of approximately 2.4 lbs. forage DM/lb. initial calf bodyweight.
An easy rule of thumb is: For wheat pasture, there are 150 to 250 lbs. of forage DM per inch of plant height. To make the math easy, use about 200 lbs. of forage DM per inch.
• Pastures that are 6 to 7 inches in height would have about 1,200 to 1,400 lbs. of forage DM per acre.
• A 500 lb. steer should have 2,500 lbs. of forage DM available at turnout (500 x 5 lbs. DM forage allowance).
• So, about 2 acres of this wheat pasture should be adequate to meet steer performance goals.
• When forage allowance falls below 2 lbs. of forage per pound of steer bodyweight, supplementation should be considered. — Paul Beck, Oklahoma State University Extension beef nutrition specialist
