Now showing items 21-34 of 34

    • How Komondor Dogs Reduce Sheep Losses to Coyotes

      McGrew, J. C.; Blakesley, C. S. (Society for Range Management, 1982-11-01)
      Nine Komondor dogs were observed guarding lambs in two 65-ha enclosures for 21 days each. Each enclosure had a resident coyote chosen for sheep-killing ability. Komondorok guarded sheep by being near the flock and actively defending it when necessary. Guarding was most effective in the area where the dogs spent most of their time. Aggressive dogs were generally more successful protecting their sheep. The sheep learned to run to or stand with the dogs when attacked, and usually bedded with the dog. The coyotes learned to attack the flock when the dog was not present. Effectiveness of Komondor dogs can be enhanced by exploiting breed characteristics.
    • High and Low Sodium Biotypes of Fourwing Saltbush: Their Responses to Sodium and Potassium in Retorted Oil Shale

      Richardson, S. G. (Society for Range Management, 1982-11-01)
      Two of 5 populations of fourwing saltbush (Atriplex canescens) examined in eastern Utah did not accumulate appreciable amounts of sodium in leaf tissue while 3 populations did accumulate sodium in leaves. The characteristics of sodium accumulation and nonaccumulation were exhibited in these populations when leaf tissue was collected from plants growing in the field or from plants grown in saline retorted oil shale in 2 greenhouse pot experiments. The plants that were low in sodium were higher in potassium but lower in total sodium plus potassium. Growth of plants from the low sodium populations was enhanced by addition of potassium to the retorted oil shale but potassium addition had no effect on growth of the high sodium plants. Top growth of the high sodium plants was greater than growth of the low sodium plants on retorted oil shale.
    • Growth and Nonstructural Carbohydrate Content of Southern Browse Species and Influenced by Light Intensity

      Blair, R. M. (Society for Range Management, 1982-11-01)
      Three species of palatable deer browse (flowering dogwood, yaupon, and Japanese honeysuckle) were grown under 3 levels of light intensity: 100, 45, and 8% of full sunlight. After 4 growing seasons, dogwood and yaupon under 45% light were significantly taller, contained more growing points, and produced a larger foliar, stem, and root biomass than plants under other light regimes. Twig growth and biomass were generally poorest in full sunlight, whereas foliar and root biomass were poorest in deep shade. Leaves of all species were smallest on plants in full sunlight. The dry weight per unit of leaf area and the concentration of total nonstructural carbohydrates in leaves declined for all species as light intensity declined.
    • Germination Responses of Esyenhardtia texana and Leucaeena retusa

      Whisenant, S. G.; Ueckert, D. N. (Society for Range Management, 1982-11-01)
      Germination and radicle growth of kidneywood and little-leaf leadtree were greatest at 30°C but occurred under a wide range of temperatures. Germination and radicle growth of kidneywood seed did not differ over the pH range of 5 to 9. Germination of little-leaf leadtree was lower at pH 5 and 6 than at pH 7 to 9. Decreased water availability reduced germination and radicle length of both species; however, kidneywood seed germination was more tolerant of moisture stress than little-leaf leadtree. Seeds of both species maintained high viability for at least 42 months after collection. An impervious seedcoat prevents germination of little-leaf leadtree seeds until it is scarified. Results from these experiments indicated no significant germination problems will be encountered in attempts to establish these plants under field conditions.
    • Forage Intake by Cattle on Forest and Grassland Ranges in Northeastern Oregon

      Holechek, J. L.; Vavra, M. (Society for Range Management, 1982-11-01)
      Forage intake was determined with steers using total fecal collections on forest and grassland vegetation types on mountain range in northeastern Oregon in 1976, 1977, and 1978. Forage intake varied from 1.6 to 2.5% of body weight (BW) on dry matter basis with a mean value of 2.1%. Forage intake did not differ (P>.05) between the two vegetation types when data were pooled across periods and years. During the summer grazing periods cattle on the forest had higher (P<.05) intakes than cattle on the grassland vegetation type. This is explained by higher forb and shrub consumption, more shade and less advanced plant phenology on the forest compared to the grassland vegetation types. Fecal collections from 5 steers for 3 days were needed to estimate fecal dry matter output with 90% confidence that the estimate was within 10% of the mean.
    • Evaluation of Different Calculation Procedures for Microhistological Analysis

      Holechek, J. L.; Gross, B. D. (Society for Range Management, 1982-11-01)
      This study evaluated 3 procedures for calculating dry weight composition of forage mixtures when microhistological analysis was used. Dividing the frequency of each species by the total frequencies of all species gave a slightly more accurate representation of dry weight composition than converting frequency to relative density or using actual density. The frequency addition procedure is much quicker than either procedure involving density.
    • Effects of Livestock Grazing on Mearns Quail in Southeastern Arizona

      Brown, R. L. (Society for Range Management, 1982-11-01)
      Grazing by domestic livestock does not limit production of food supplies for Mearns quail (Cyrtonyx montezumae mearnsi) in southeastern Arizona. Nevertheless, grazing available forage in excess of 55% by weight can nearly eliminate local quail populations by removing their escape or hiding cover just prior to the nesting season. This eliminates the breeding population itself. The 46 to 50% level of utilization by weight appears to be marginal for maintaining optimum quail populations.
    • Early Succession Following Clearcutting of Aspen Communities in Northern Utah

      Bartos, D. L.; Mueggler, W. F. (Society for Range Management, 1982-11-01)
      Changes in aspen reproduction and undergrowth production and composition were recorded over a 3-year period following clearcutting. Aspen suckers increased from 2,300 per hectare prior to cutting to a maximum of 44,000 per hectare the second post-cut year, and dropped to approximately 25,000 per hectare by the third year. Undergrowth production on the cut units increased from 1,013 kg/ha prior to cutting to 3,000 kg/ha after three growing seasons; production on the uncut control areas increased from 1,199 kg/ha to 1,539 kg/ha during this period. The significant increase in undergrowth is attributed to the reduction in competition from the removal of the aspen overstory. Clearcutting appeared to increase the proportion of shrubs in the undergrowth and decrease the proportion of forbs. A similarity index comparing the cut and uncut areas suggested that the greatest change in species composition occurred the first year after cutting, with a gradual return towards the precut conditions.
    • Diurnal Variation in Weight and Rates of Shrink of Range Cows and Calves

      Heitshmidt, R. K. (Society for Range Management, 1982-11-01)
      Cow-calf pairs were weighed on successive mornings to determine the effects of time on total weight. Early morning weights of mature Hereford/Angus crossbred cows were approximately 2.5% less than late morning weights in both the spring and summer. Weights of suckling calves were not significantly different between early and late morning. Linear regression analyses indicated drylot shrink weights of cows were primarily a function of length of time of shrink. Rate of weight loss was approximately 1% every 3 hours after an initial 3 hour loss of 3.5%. Secondary factors were status of cow (dry or wet), relative humidity (%), season (spring or summer) and initial cow weight. Shrink rates were slightly greater for wet cows than dry cows; when relative humidity was low; during spring; and for lighter weight cows. Rates of shrink of calves were primarily related to size of calf with calves weighing less than 53 kg (117 lb) gaining weight and calves weighing more than 53 kg losing weight.
    • Concepts and Factors Applicable to the Measurement of Range Condition

      Wilson, A. D.; Tupper, G. J. (Society for Range Management, 1982-11-01)
      The concept of range condition is reanalysed in terms of the nature of changes in land and vegetation and the purpose of measurement. A new framework is outlined which presents range condition as an overall concept based on change in the value of land attributes, relative to their potential value. These attributes include factors such as the composition and quantity of the vegetation, the stability of the soil and the productivity of the land in terms of animals, water yield, or amenity value. On this basis, indices of change in each attribute may be constructed from vegetation measurements. This will include separate indices of soil stability, animal productivity, and vegetation change (flora conservation), which may or may not be correlated with one another. Range condition cannot be defined by one of these attributes alone, so that the separation of ecological and productivity-based methods is artificial. Overall the importance of soil stability is considered to be greater than productivity, which in turn is greater than vegetation change, but this will depend on the type of land and the dominant land use.
    • Comparison of Micro- and Macro- Digestion Methods for Fiber Analysis in Forages and Ruminant Diets

      Holechek, J. L.; Vavra, M. (Society for Range Management, 1982-11-01)
      Micro-methods for analyses of neutral detergent fiber (NDF), acid detergent fiber (ADF), and permanganate lignin were compared to the macro-methods of Van Soest (1963) and Van Soest and Wine (1967, 1968). Differences between the two methods were small although the micro-methods gave better precision for ADF while the macro-method gave better precision NDF and lignin. Time and reagents needed for analysis were reduced over 60% with the micro-digestion methods.
    • Cattle Diet and Daily Gains on a Mountain Riparian Meadow in Northeastern Oregon

      Holechek, J. L.; Vavra, M.; Skovlin, J. (Society for Range Management, 1982-11-01)
      Cattle weight gains, diet botanical composition, and diet quality on a riparian meadow range in the Blue Mountains of eastern Oregon were evaluated in the late summer and fall in 1976, 1977, and 1978. Pregnant yearling heifers were used to evaluate livestock performance. Esophageally fistulated cows were used to evaluate diet botanical composition and diet quality. Cattle diets showed little difference in botanical composition between periods or years. Grasses comprised an average of 80% of the diet during the 3 year period. Kentucky bluegrass (Poa pratensis) was the most important grass in cattle diets and had the highest percent cover on the study pastures. Cattle diet quality showed little change within or between years. Crude protein concentrations appeared adequate for cattle to gain .5 kg per day. However, estimated digestible energy concentrations averaged only 80% of that recommended by the NRC. Daily gains were erratic between and within years averaging .41 kg for the 3 years. Average daily gains on the meadow were better than or equal to those reported in other studies for upland and upland and meadow pastures at the Starkey Range for the same periods. Separate fencing and deferred grazing of mountain meadows could improve cattle performance and aid ranchers in gathering cattle at the end of the grazing season. In addition deferred grazing should result in pasture improvement and provide better habitat for nesting birds. The primary disadvantage of deferred use of meadows would be the cost of fencing.
    • Biomass and Forage Production from Reclaimed Stripmined Land and Adjoining Native Range in Central Wyoming

      Lang, R. (Society for Range Management, 1982-11-01)
      Aboveground biomass and forage production from native range and adjacent reclaimed stripmined land were measured in 1977. On 2 of the 4 native range transects the aboveground biomass was greater than on reclaimed areas, largely due to big sagebrush and mat-forming species. Forage production, defined as the vegetation consumed by domestic grazing animals on properly grazed range, was equal to or greater on the reclaimed land than on adjoining native range.
    • Annual Grassland Response to Fire Retardant and Wildfire

      Larson, J. R.; Duncan, D. A. (Society for Range Management, 1982-11-01)
      Diammonium phosphate (DAP), air-dropped in early autumn 1974 to contain a wildfire on the San Joaquin Experimental Range in California, applied high levels of nitrogen and phosphorus to foothill annual grassland. The DAP drop and fire provided 4 treatments for the study-unburned + DAP, burned + DAP, burned and unburned (control). In the first year both of the DAP treatments, with yields of more than 12,000 kg/ha produced twice that of the unburned (control). First-year forage yields for the unburned and burned plots were not significantly different. The second year the burned plot yielded almost twice that of the unburned. The second year, the unburned + DAP plot produced about 4200 kg/ha, the highest yield of all 4 plots, and significantly higher than the burned + DAP plots. Annual and seasonal weather patterns and soil moisture affected herbage composition more than treatments. Although forbs usually increase in annual grassland after fire, and nitrogen fertilizer favors grasses, grasses nonetheless dominated on all 4 treatments in the first year. Forbs were dominant the second year. The difference in relative percent composition of grasses and forbs was greater between years than between treatments.