Browsing Journal of Range Management, Volume 47, Number 2 (March 1994) by Subjects
Now showing items 1-3 of 3
Cattle preference for 4 wheatgrass taxaWe compared the preference of cattle for 12 entries, 2 of crested wheatgrass [Agropyron desertorum (Fischer ex Link) Schultes], 5 of thickspike wheatgrass [Elymus lanceolatus (Scribner & J.G. Smith) Gould ssp. lanceolatus], 3 of Snake River wheatgrass (proposed name E. lanceolatus spp. wawawaiensis), and 2 of bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) A. Love] in May 1989 and 1990 at Logan, Utah. Spaced plants were randomly arranged in 4 paddocks which were grazed once by 2 animals in late spring each year. Number of bites and number of visits were recorded for each entry in each paddock for the 2 animals individually. Cattle preferred Hycrest and Nordan crested wheatgrasses both years. Number of bites per plant for crested, thickspike, Snake River, and bluebunch wheatgrasses averaged 9.1, 4.3, 3.1, and 4.1, respectively, in 1989 and 6.7, 3.3, 3.5, and 3.6, respectively, in 1990. Number of visits was highly correlated with number of bites across entries. Grazing preference among entries was more highly correlated with biomass score and canopy height than basal area or maturity. Cattle preferred crested wheatgrass over the native wheatgrasses tested here during the spring grazing season.
Pre-laying nutrition of sage grouse hens in OregonDiet, dietary selection, and nutritional composition of the food of sage grouse (Centrocercus urophasianus) hens were determined during the pre-laying period in southeastern Oregon in 1990 an 1991. We collected 42 female sage grouse during a 5-week period preceding incubation (4 March-8 April). Sagebrush (Artemisia spp.) was the most common among 21 foods consumed but forbs composed 18 to 50% of the diet by weight. Desert-parsley (Lomatium spp.), hawksbeard (Crepis spp.), long-leaf phlox (Phlox longifolia Nutt.), everlasting (Antennaria spp.), mountain-dandelion (Agoseris spp.), clover (Trifolium spp.), Pursh's milk-vetch (Astragalus purshii Dougl.), buckwheat (Eriogonum spp.), and obscure milk-vetch (A. obscurus) were the primary (greater than or equal to 1% of the diet by weight) forbs consumed. Forbs were used selectively over sagebrush in both low and big sagebrush cover types. All forbs were higher in crude protein and phosphorus and many were higher in calcium than sagebrush. Consumption of forbs increased nutrient content of the composite diet. Substantially fewer forbs were present in the diet in 1991 than in 1990, which coincided with reduced sage grouse productivity on the study area. These results suggest that consumption of forbs during the pre-laying period may effect reproductive success by improving nutritional status of hens.
Social facilitation influences cattle to graze locoweedMany ranchers claim that if a cow starts eating locoweed, she will teach others to eat it. Three grazing trials were conducted to evaluate the role of social facilitation in starting cattle to graze locoweed. The first trial was conducted near Gladstone, N.M., using mature cows grazing woolly locoweed (Astragalus mollissimus var. mollissimus Torr). The second trial was conducted on the Raft River Mountains in northwestern Utah, using yearling cattle grazing white locoweed (Oxytropis sericea Nutt). The third trial was conducted to determine if aversion-conditioned yearling cattle would consume white locoweed when placed with cattle that were eating locoweed (loco-eaters). Cattle conditioned to eat locoweed and naive animals in trials 1 and 2 first grazed in separate pastures to evaluate their initial acceptance of locoweed. The groups in the respective trials then were placed together to evaluate the influence of social facilitation on locoweed consumption. Locoweed consumption was quantified by bite count. Naive cattle in trials 1 and 2 sampled small quantities of locoweed while grazing separately. However, they greatly increased locoweed consumption when placed with the loco-eaters. Aversion-conditioned cattle in trial 3 did not consume locoweed while grazing separately. When placed with loco-eaters, they gradually increased consumption of white locoweed, in contrast to the immediate acceptance of locoweed by naive cattle in trials 1 and 2. The aversion extinguished and averted animals eventually accepted white locoweed at levels comparable to loco-eaters. Results of this study demonstrate that social facilitation can cause cattle to start eating locoweed.