The notion that it takes a couple of weeks to bring calves up to speed on wheat pasture may be more myth than reality, according to research conducted at Oklahoma State University (OSU).
Glenn Selk, OSU Extension cattle reproduction specialist, explains grazing studies were conducted two consecutive winters at the OSU wheat pasture research unit to determine body weight change throughout the winter grazing period.
During the first winter, 34 Angus steers (494 lbs.) were grazed on wheat pasture for 166 days. The next winter, 28 Angus steers (502 lbs.) were managed on the wheat pasture for 163 days. Grazing started on Nov. 11 and Nov. 14, respectively, and the steers were removed from the wheat on April 26 each year. The steers were weighed 15 times during year one; seven times during year two. Because of differences in weather and forage growth, stocking rates varied from 1.83 acres/steer the first year to 3.07 acres/steer in the second year.
“With surprising consistency, the steers gained in excess of 3 lbs./day throughout the course of a 160-day grazing season,” Selk says. “These data indicate that there is not a significant adaptation period for steers grazing winter wheat pasture.”
OSU researchers conducting the study included Gerald Horn and David Lalman. In their report, they explain, “When monitoring short-term weight gain of animals, many factors come into play that can influence weight measurements. Paramount among these is amount of rumen fill (shrunk vs. un-shrunk weights, or a recent change in type and dry-matter content of the diet). Also, when evaluating body weight gains, it is important to realize that brief snapshots of an animal's performance may be less important than the overall trend for the entire production period. In the case of winter wheat pasture, a desirable length of grazing would be 100 days or more, depending on whether a grain crop is harvested or not. During the course of this production period there may be times when an animal is not as productive as other times. This can be due to environmental or forage availability and quality issues.”
Go to www.ansi.okstate.edu/ for the complete study.