Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 16, 2010
Publication Date: July 9, 2010
Citation: Gunter, S.A., Springer, T.L., Thacker, E.T., Gillen, R. 2010. Effects of sand sagebrush control on stocker cattle performance on a Southern mixed prairie community. Proceedings of the 4th Grazing Livestock Nutrition Conference, July 9-10, 2010, Estes Park, Colorado. p. 208. Technical Abstract: Research on sand sagebrush communities has focused primarily on sagebrush control methods, with little attention to effects on livestock production. To evaluate the effects of sand sagebrush (Artemisia filifolia) control on cattle production, 15 native pastures (10 to 21 ha each) were selected in 2003 at the Southern Plains Experimental Range near Ft. Supply, Oklahoma. Five of the pastures had recently (< 5 yr) been sprayed with 2,4 dichlorophenoxyacetic acid to control sand sagebrush, 6 had received chemical treatment before 1994, and the remaining 4 had received no treatment. The 15 pastures were categorized into 3 discrete sagebrush levels based on past management: 1) High with no sagebrush control within the last 60 yr, 2) Medium with sagebrush control at least 9 yr and older, and 3) Low with sagebrush sprayed in 2003 with 1.1 kg of 2,4 dichlorophenoxyacetic acid (a.i.)/ha. The average sagebrush canopy cover from 2003 to 2008 in the High, Medium, and Low pastures was 26.4 (n = 4), 10.0 (n = 6), and 3.0% (n = 5), respectively, as determined annually by the line-transect method. The major grass species in the pastures were blue grama (Bouteloua gracilis), sand dropseed (Sporobolus cryptandrus), little bluestem (Schizachyrium scoparium), sand lovegrass (Eragrostis trichodes) and sand bluestem (Andropogon hallii). From 2004 to 2008, approximately 106 steers (BW = 202 ± 6.1 kg) were stocked annually in late January and subsequently removed in mid-August. High pastures were stocked at 47 animal-unit-d/ha and Medium and Low pastures were stocked at 69 animal-unit-d/ha. Cattle were supplemented with oil seed meal based cubes (48% CP) from January through mid-April at a rate of 0.68 kg/steer daily; no supplement was fed from April to August. Mineral blocks (NaCl) were available during the entire trial. Initial BW in January did not differ (P = 0.57) among treatment (203, 201, and 202 kg for High, Medium, and Low, respectively). Also, BW did not differ (P = 0.76) in April (236, 235, and 235 kg for High, Medium, and Low, respectively, or at removal in August (P = 0.12; 352, 344, and 346 kg for High, Medium, and Low, respectively). Average daily gains from January to April did not differ (P = 0.96), but did differ from April to August (P = 0.02). Steers grazing the High pastures gained BW faster (P < 0.01; 1.03 kg/d) than steers grazing Medium pastures (0.96 kg/d) and tended to gain faster (P = 0.08) than steers grazing Low pastures (0.98 kg/d). Body weight gain per steer during the January to April grazing period did not differ (P = 0.80). However, steers in the High pasture had higher BW gain per steer from April to August (P < 0.01) than steers in the Medium pastures. Steers in the Medium pastures tended (P = 0.08) to have higher BW gain per steer than the Low pastures. Even with the differences in BW gain per steer during the summer, the overall BW gain per steer did not differ (P = 0.14). Body weight gain per hectare was greatest (P < 0.01) for Low pastures (102 kg) compared to High (67 kg) or Medium (81 kg) pastures; also, Medium pastures were greater (P < 0.01) than High pastures. No sagebrush control (High), with an appropriate stocking rate resulted in the lowest BW gain hectare. However, the use of intensive sagebrush control (Low; spraying every 5 yr) and increasing the stocking rate (47%) over the High pastures resulted in a 26% increase in BW gain per hectare. However, the moderate sagebrush control (Medium; spraying intervals of approximately 10 yr) resulted in performance similar to that of the Low pastures. These results suggest that medium levels of sand sagebrush control with appropriate stocking rates may be the best management option for stocker cattle production.