|Jones, Rodney - Oklahoma Cooperative Extension System|
|Gillen, Robert - Kansas State University|
Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2011
Publication Date: 3/12/2012
Publication URL: http://handle.nal.usda.gov/10113/55116
Citation: Gunter, S.A., Thacker, E.T., Gillen, R.L., Springer, T.L., Jones, R. 2012. Effects of sand sagebrush control in southern mixed-grass prairie rangeland on cattle performance and economic return. Professional Animal Scientist. 28:204-212.
Interpretive Summary: Herbicides have been used in northwest Oklahoma since the 1960’s to control sand sagebrush in native rangelands and to promote increased grass and livestock production. Even though this management option has been used for many years, few studies have examined its effect on plant communities, cattle performance, or economic returns. In northwest Oklahoma, pastures were selected with different levels of sagebrush cover, resulting from herbicide control, and stocked with steers from January through August according to predicted herbage production. Removing the sagebrush resulted in an increase in the percentage of the ground surface covered by grasses and an increased density of annual forbs. Individual steer performance did not differ as a result of sagebrush cover in the winter but average daily gain was improved during the summer in pastures containing less sagebrush. Because the removal of sagebrush increased the number of grass plants in the pastures, carrying capacity was increased. Hence, removing sagebrush and deceasing cover level from 26% to 5% increased steer gain per acre by 52%. Because steer gain per acre was dramatically increased, economic net return was best for pastures with the least sagebrush. Even though removal of the sagebrush was most profitable to the cattle enterprise, this practice could limit the number of ecological services the rangeland could provide because of the loss of protective cover for wildlife.
Technical Abstract: To evaluate the effects of sand sagebrush (Artemisia filifolia Torr.) control in native rangelands on cattle performance, 15 pastures (10 to 21 ha each) were selected in Northwest Oklahoma. Eleven pastures had been sprayed with 2,4-dichlorophenoxyacetic acid in 1984 or 2003 to establish differences in sagebrush cover. The pastures were categorized into 3 sagebrush cover levels: 1) HIGH (27 ± 2.7% cover, n = 4), 2) MEDIUM (10 ± 2.7% cover, n = 6), and 3) LOW (5 ± 2.7% cover, n = 5). From 2004 to 2008, steers (Body Weight (BW) = 202 ± 6.1 kg) were stocked annually in late January and grazed until mid-August. HIGH, MEDIUM, and LOW pastures were stocked at 47, 69, and 69 animal-unit-d/ha, respectively. Cattle were supplemented with oil seed based cubes (41% Crude Protein) from January through April at a rate of 0.68 kg/steer daily. From January to April, Average Daily Gain did not differ (P = 0.96) among treatments, but from April to August steers grazing the HIGH pastures gained BW faster (P < 0.01; 1.03 kg) than steers grazing MEDIUM pastures (0.96 kg) and tended to gain BW faster (P = 0.08) than steers grazing LOW pastures (0.98 kg). Gain of BW per hectare was greatest (P < 0.01) for LOW pastures (102 kg) compared to HIGH (67 kg) or MEDIUM (81 kg) pastures. The net return per hectare of the LOW pastures was highest with MEDIUM intermediate and HIGH the least. These results suggest that increasing levels of sagebrush control with appropriate adjustments in stocking rates are most profitable for stocker cattle production considering no other ecological service.