Pasture & Range: February 2003 Soils: February 2003

It seems I have been asked about growing wheat for grain more this fall than in the recent past. Of course, producers still want their fall grazing, but it appears that wheat prices may be slightly above $3 per bushel this spring, providing the option to defer spring grazing and harvest grain. A survey conducted by Oklahoma State University in 1995-96 reported that 66 percent of Oklahoma producers grow dual-purpose wheat, used for both forage and grain (True, et. al., 1996). When is the best time to remove cattle from winter pasture to avoid losing grain yield potential? Remove too early and you lose potential daily beef gain. Leave cattle on too long and you can drastically reduce grain yield. Since two-thirds of Oklahoma wheat producers grow dual-purpose wheat, knowing the correct time to terminate grazing is critical to maximize the economic return per acre to such an enterprise.

First hollow stem stage (from OSU publication Wheat Management in Oklahoma — A Handbook for Oklahoma's Wheat Industry; Chapter 5: Wheat as Forage)

To avoid grain yield loss, all grazing should stop at first hollow stem or "jointing." Jointing is defined as the growth stage when hollow stem can be first identified above the roots and below the developing head. It is important to note that jointing occurs when the developing seed head is below the soil surface. To scout for jointing, dig up one of the larger plants from an ungrazed area (outside the fence or from an enclosure) and cut it off just above the roots. Then dissect vertically upwards to the newest leaves. Figure 1 describes what to look for. If you see the developing seed head with 1/4 to 3/4 inches of hollow stem between this point and the roots, grazing should be terminated. All too often, a calendar date is used to terminate grazing. The most common date for cattle removal is March 1. Using a date is risky because a number of variables affect jointing, including weather conditions, variety and planting date. The largest factor is the weather in January and February. Above-normal temperatures encourage earlier jointing, while below-normal temperatures may delay jointing. Also, wheat planted in late August will joint earlier than October-planted wheat.

Work done at Oklahoma State University by Dr. Gene Krenzer best explains the advantages of terminating grazing at jointing (OSU Fact Sheet PT 95-10). This research reported that terminating grazing two weeks prior to jointing had little effect on the net economic return per acre (Figure 2). However, delaying cattle removal just one week can reduce the net return $23 per acre. Waiting two weeks after jointing reduces the net return as much as $55 per acre. These dollar per acre estimates could be different depending on the value of gain on stocker calves and wheat prices.

It is important to mention that the net return from cattle increases as the grazing season is increased due to daily gain. However, net returns from grain decrease rapidly when grazing is continued after jointing. Beef gains after jointing generally do not compensate for lost grain yield. In general, net returns are less negatively impacted by removing cattle early and giving up a few days of beef gain than by continuing to graze a few days after jointing.

(from OSU publication Wheat Management in Oklahoma — A Handbook for Oklahoma's Wheat Industry; Chapter 5: Wheat as Forage)

References
Krenzer, Gene. 1997. Economic Impact of Grazing Termination in a Wheat-Grain Stocker Cattle Enterprise. OSU Cooperative Ext. Service, PT 97-5, Vol. 9, No. 5.

Royer, Tom A. and Gene Krenzer, eds. 2001. Wheat Management in Oklahoma — A Handbook for Oklahoma's Wheat Industry. E- 831.

True, Randy, F. Epplin, E. Krenzer, G. Horn. 1996. A Survey of Wheat Production and Wheat Forage Use Practices in Oklahoma. OSU Cooperative Ext. Service, B-815.