• Seasonal Diurnal Variation in Composition of Cow Diets

      Kirby, D. R.; Stuth, J. W. (Society for Range Management, 1982-01-01)
      Seasonal diets between fall 1977 and spring 1979 were collected in morning and evening from esophageally fistulated cows in the Post Oak Savannah of east-central Texas. Chemical content of diurnal diets were similar within a season except CP was higher in evening collections as compared to morning collections during fall. Cows appeared to select for energy (IVDOM) over CP. Botanical composition of morning and evening diets differed only during summer. Since the cows spent more time during hot summer afternoons in the shade of woody plants, less grass and more forbs, vines, and woody vegetation were selected. Research based on morning diet collections only might result in biased samples. Recognition of nutritional and environmental stresses with potential to alter grazing behavior of animals is critical for accurate sampling of livestock diets.
    • Summer Grazing of Sagebrush-Grass Range by Sheep

      Harniss, R. O.; Wright, H. A. (Society for Range Management, 1982-01-01)
      Sagebrush-grass range normally grazed in the spring and fall can be grazed in the summer to provide a maintenance ration for ewes if their lambs are weaned early. Moderate grazing (57-99 sheep days/ha) in early or late summer did not change vegetative composition or yields. Heavy grazing (185-198 sheep days/ha) in the early summer decreased yields of grasses and the cushion-forb Hoods phlox. Late summer grazing did not change the grass or forb yields. Sagebrush yields increased in the sagebrush subtype where balsamroot was abundant under early summer grazing.
    • The Occurrence of Anagyrine in a Collection of Western American Lupines

      Davis, A. M. (Society for Range Management, 1982-01-01)
      The alkaloid anagyrine found in some Lupinus species has been shown to cause the teratogenic condition known as "crooked calf disease." A collection of western American lupines held by the Western Regional Plant Introduction Station was grown at Pullman, Washington, to determine the extent and levels of anagyrine in these accessions. The plants were field grown on Tucannon soil, a fine-silty, mixed, mesic pachic Haploxerolls. Anagyrine determinations were made by gas/liquid chromatography. Accessions that were positive for anagyrine in June 1977 were resampled and verified in 1978. Anagyrine and total alkaloids were higher in April and markedly diminished by July. Seeds were higher in total alkaloids and anagyrine, when present, than was mature vegetation.
    • The Persistence of Fenitrothion Insecticide In Red Maple (Acer rubrum L.) and White Birch (Betula papyfifera (Marsh.)) Deer Browse

      Lapierre, L. E. (Society for Range Management, 1982-01-01)
      From May 15 to November 15, 1977, vegetation plots were monitered on a constant basis in order to obtain the concentration of fenitrothion in red maple and white birch deer browse. The data obtained indicates that the concentrations tend to be as high as 21.413 ppm for the red maple and 19.371 ppm for the white birch immediately following the spray application. However, the concentrations are below 0.010 ppm 120 days following the application. Fenitroxon was detected in two of the samples taken from the sprayed plots. None was detected within the control plots. There is no evidence in the literature that a concentration of fenitrothion of the magnitude detected would have obvious effects on deer populations during their winter yarding.
    • Vegetative and Reproductive Growth of Bluebunch Wheatgrass in Interior British Columbia

      Quinton, D. A.; McLean, A.; Stout, D. G. (Society for Range Management, 1982-01-01)
      Vegetative and reproductive growth of bluebunch wheatgrass in interior British Columbia has been documented for a 3-year period. Plants began growing immediately after snow melt in the spring, with measurable growth occurring where soils had warmed to 6 +/- 0.5 degrees C at 10-cm depths. Growth ceased from 7 May to 15 July and plants fully matured from 7 July to 10 August with actual dates for each particular site being dependent upon the local microclimate. Fall regrowth was not predictable, occurring only during 1973. Seed production was erratic, unpredictable from our data, and not of sufficient magnitude to sustain the grass population if improper grazing is allowed.