• A Comparison of Three Methods of Estimating Digestibility for Determining Intake of Grazing Cattle

      Handl, W. P.; Rittenhouse, L. R. (Society for Range Management, 1975-09-01)
      In vitro plus pepsin digest (IVP), lignin ratio (LR), and in vitro plus neutral detergent digest (IVND) were of about equal value in estimating digestibility of spring forage grazed by steers, provided the limitations of each were considered. However, when these methods of estimating digestibility were used to estimate intake, only the IVP and LR methods gave realistic results. The IVND results were lower than the expected physical capacity of the animals, and indicated further study of this method is needed.
    • A Comparison of Twig-length and Browsed-twig Methods of Determining Browse Utilization

      Jensen, C. H.; Scotter, G. W. (Society for Range Management, 1977-01-01)
      Utilization of shrubs has been determined by several techniques, two of which are: (1) measuring twig lengths before and after use then calculating the percentage and (2) estimating the percentage of browsed twigs. Estimates were checked for accuracy by actually counting the number of browsed and unbrowsed twigs and then calculating percentages. The two methods were compared on a big game winter range in southcentral Utah to evaluate the agreement among utilization estimates, consistency among individual observers, and efficiency. Estimating the percentage of browsed twigs or calculating percentages from counts of browsed and unbrowsed twigs provided higher utilization values than measuring twig lengths. Disadvantages of estimating percentages of browsed twigs include the introduction of individual bias when estimates are made and lack of sensitivity in accurately determining percentage utilization under heavy use. By contrast, calculating percentages of utilization from twig length measurements provided equal sensitivity throughout the 0 to 100% range. Twig measurement data were more consistent among observers than estimates. Measuring twig lengths required about four times as many man-hours as estimating percentages of browsed twigs or counting twig numbers.
    • A comparison of two furrow opener-depth control assemblies for seeding forage grasses

      Lawrence, T.; Dyck, F. B. (Society for Range Management, 1990-01-01)
      Seed from 45 strains of grass were sown with 2 drills fitted with different furrow openers and depth control devices. Standard (34-cm diameter) double disk openers (Kirchman (Lilliston Melroe)) fitted with depth control bands 2 cm wide and 5 cm smaller in diameter than the disk were used to seed 1 trial at a seeding depth of 2.5 cm. This seeding was compared to forage crop stands obtained from a drill fitted with an experimental opener using 2 disks of unequal diameter, the larger (38 cm diameter) running vertical and the smaller (28 cm diameter) angled at 7 degrees. The center for mounting the small disk is 5 cm below and 2.5 cm behind the large disk, thus the bottoms of the disks are on the same horizontal plane. Seeding depths of 2.5 cm and 6.25 cm were accomplished by an adjustable rubber-tired depth gauge wheel assembled beside the large disk. At the 2.5 cm depth of seeding, the large-small disk opener assembly resulted in superior forage establishment compared to that obtained with the standard double disk assembly. Comparing either opener-depth control assembly set to seed at 2.5 cm depth with the large-small disk assembly set to seed at 6.25 cm depth confirmed the value of shallow seeding of forage crops to overcome establishment problems.
    • A Comparison of Two Grass Sampling Methods for Digestibility Trials Conducted on Pasture

      Smith, E. F.; Young, V. A.; Holland, L. A.; Fryer, H. C. (Society for Range Management, 1959-11-01)
    • A Conservation Program for Grazing Woodlands in the Southwest

      Shiflet, T. N. (Society for Range Management, 1963-01-01)
    • A Core Sampler for Excavating Grass Roots

      Browns, James; Box, Thadis W. (Society for Range Management, 1964-01-01)
    • A cow-calf vs yearling substitution ratio for shortgrass steppe

      Forero, L.; Rittenhouse, L. R.; Mitchell, J. E. (Society for Range Management, 1989-07-01)
      Managers often deal with the problem of herd replacement of one animal class by another. A preliminary study suggested that steers could be substituted for cow-calf pairs on shortgrass steppe on a weight:weight basis. This ratio was tested on 2 pairs of pastures, one dominated by native shortgrass steppe and the other by a seeded stand of sideoats grama (Bouteloua curtipendula (Michx.)Torr.). The pasture sizes were set so the cow-calf pastures were 1.8 times larger than the steer pastures to allow equal herd sizes for the 2 classes of animals. Adequacy of stocking was determined by equalizing utilization. The actual stocking ratios of 1.79 steers to 1 cow-calf pair on the native pastures and 1.78 steers to 1 cow-calf pair on the seeded pastures resulted in no significant differences in utilization or standing crop of remaining forage after the grazing season ended. Season-long, the 90% confidence bounds of the steer-weight:pair-weight ratio was 0.981-1.035 and 0.968-0.985 for native and seeded pastures, respectively. This ratio provides an acceptable initial stocking rate guide for those wishing to change from cow-calf to steer operations, or vice versa, on the shortgrass steppe.
    • A Device for Cutting Uniform Inch-Height Segments of Plants and Plant Parts

      Hickey, Wayne (Society for Range Management, 1964-05-01)
    • A Device for Determining Boundaries of Browse Plots

      Rhodes, R. R. (Society for Range Management, 1953-09-01)
    • A Device to Aid in Selecting and Counting Seeds

      Brown, Gary R. (Society for Range Management, 1967-01-01)
    • A digital photographic technique for assessing forage utilization

      Hyder, P. W.; Fredrickson, E. L.; Remmenga, M. D.; Estell, R. E.; Pieper, R. D.; Anderson, D. M. (Society for Range Management, 2003-03-01)
      Changes in forage utilization have been difficult to measure non-destructively without some level of subjectivity. This subjectivity, combined with a lack of reproducibility of visual estimates, has made forage utilization measurement techniques a topic of considerable discussion. The objective of this study was to develop and test the accuracy and repeatability of an objective, computer-based technique for measuring changes in plant biomass. Digital photographs of target plants acquired before and after partial defoliation were analyzed using readily available image analysis software. Resulting data were used to develop a simple linear random coefficient model (RC) for estimation of plant biomass removed based on the area of the plant in the photo. Sample collection took approximately 20 minutes/plant for alfalfa (Medicago sativa L.). Analysis of images took another 60 to 90 minutes. Regression analysis gave an R2 of 0.969 for predicted vs. observed plant weights. Testing this model using 10 alfalfa plants yielded weight estimates of defoliated plants accurate to within +/- 8.5%. The advantage of the RC model is its ability to use easily obtained coefficients from simple linear regression models developed from each plant in a way that accounts for the lack of independence between samples within an individual plant. The technique described here offers an objective and accurate method for measuring changes in plant biomass with possible applications in ecology, botany, and range science. In particular, application of this technique for estimating forage utilization may improve accuracy of estimates and, thereby, improve range management practices.
    • A digital technique for recording of plant population data in permanent plots

      Roshier, D.; Lee, S.; Boreland, F. (Society for Range Management, 1997-01-01)
      A mobile system to rapidly record demographic and spatial data of plant populations on permanent plots has been developed based on digital image processing equipment for personal computers. It offers considerable savings in field and data handling time and can record data from large plots. This system will facilitate broader application of plant demographic studies to arid and semi-arid ecosystems.
    • A Direct Approach for Quantifying Stream Shading

      Clark, Patrick E.; Johnson, Douglas E.; Hardegree, Stuart P. (Society for Range Management, 2008-05-01)
      Management and regulatory standards for stream shading have been established to mitigate excessive stream temperature. Existing shade assessment tools, however, are inadequate for monitoring extensive stream networks. Our objectives were to develop and evaluate an efficient, low-cost field technique for sampling stream-surface shading using digital images and to evaluate the efficiencies and effectiveness of eight different digital image analysis techniques for shade assessments. We developed a quadrat-based technique and associated field equipment to directly photograph stream-surface shading. Sampling at random points (pixels) within the resultant digital images was the most accurate, efficient, and robust image analysis technique. An approach pairing the photographic field technique and the random point-sampling image analysis technique should enable managers to conduct ground-based assessments of stream shading over extensive stream networks. This approach may also provide an efficient means of collecting ground truth samples for even broader scale, remote sensing-based stream- shade assessments. 
    • A Dissimilarity Coefficient and Its Use

      Bonham, C. D. (Society for Range Management, 1982-01-01)
      A coefficient of dissimilarity was used to test hypotheses concerned with standing crop of individual plant species occurring on two soil types and subjected to two levels of cattle grazing. It was concluded that variations in relative biomass of individual species changed with grazing, but biomass by species did not vary over the growing season on deep sandy soils.
    • A Double Sampling Technique for Estimating Dietary Composition

      Peden, D. G.; Hansen, R. M.; Rice, R. W.; Van Dyne G. M. (Society for Range Management, 1974-07-01)
      A double sampling technique is described which has a potential to increase sampling accuracy and efficiency when estimating botanical composition of herbivore diets. When applied to wild herbivores this technique may also reduce the need for using fistulated and thus behaviorally abnormal animals.
    • A Durable Esophageal Cannula for Sheep and Goats

      Taylor, C. A.; Bryant, F. C. (Society for Range Management, 1977-09-01)
      Problems often arise in the selection of a permanent esophageal cannula to be used in fistulated animals. A permanent cannula constructed from PVC pipe and Plexiglas is described which has strength, rigidity, and durability while keeping costs to a minimum.
    • A Durable Livestock Exclosure for Herbage Production and Utilization Sampling

      Hinnant, R. T.; Kothmann, M. M. (Society for Range Management, 1982-01-01)
    • A Durable, Economical Cage for Utilization or Production Studies

      Wilbert, D. E. (Society for Range Management, 1961-11-01)