• Alfalfa Survival and Vigor in Rangeland Grazed by Sheep

      Berdahl, J. D.; Wilton, A. C.; Lorenz, R. J.; Frank, A. B. (Society for Range Management, 1986-01-01)
      Few detailed comparisons have been made among alfalfa (Medicago spp.) cultivars and strains grazed in semiarid, rangeland environments. The objective of this study was to determine survival and vigor of alfalfa cultivars and experimental strains that were grown in association with rangeland grasses and grazed by sheep for 3 seasons. Three-month old seedlings of 5 cultivars and 6 experimental strains of winterhardy alfalfa were transplanted in June 1979 into grass sod on 0.9-m centers at a hillside site with a west-facing 16% slope and Amor loam (Typic Haploboroll) soil. Dominant vegetation was western wheatgrass (Pascopyrum smithii (Rydb.) Löve. Syn: Agropyron smithii (Rydb.)], blue grama [Bouteloua gracilis (H.B.K.) Lag.], and smooth bromegrass (Bromus inermis Leyss.). For 3 seasons after the establishment year, each replicate was grazed in sequence for 2 weeks at a stocking rate of 48 yearling ewes/ha during summer and then mowed to a height of 10 cm in September. Only 5 of the 11 entries had greater than 50% survival after the third season. Three germplasm pools derived from local alfalfa plantings that had persisted more than 50 years in association with rangeland grasses were highest in survival, ranging from 72-74%. Drylander and Roamer, 2 cultivars developed primarily for grazing in semiarid regions of western Canada, had 65 and 62% survival, respectively. Phenotypic variability found among surviving plants in this study will permit further genetic improvements in alfalfa for rangeland.
    • Anagyrine in Western American Lupines

      Davis, A. M.; Stout, D. M. (Society for Range Management, 1986-01-01)
      The teratogenic condition known as 'crooked calf disease' occurs when pregnant cows eat certain lupines with anagyrine concentrations at or above 1.44 g kg-1 dry matter between the 40th and 70th day of pregnancy. Five of eight species collected in Oregon and Washington had accessions with anagyrine at or above the hazardous concentrations as determined by gas/liquid chromatography. A total of 14 species of lupine are now shown to contain accessions with potentially hazardous concentrations of anagyrine. Any range/livestock management system that will expose susceptible cattle to anagyrine-bearing lupines could result in serious calf crop losses.
    • Annual Medics and Related Species as Reseeding Legumes for Northern Utah Pastures

      Rumbaugh, M. D.; Johnson, D. A. (Society for Range Management, 1986-01-01)
      Legumes are beneficial in providing high quality forage and enhancing fertility levels in the soil by biological nitrogen fixation. Nonperennial Medicago species have a world-wide distribution and have been used successfully for grazing in Mediterranean-type environments. The feasibility of using nonperennial Medicago species as reseeding pasture legumes in the northern Utah area was evaluated at 2 locations in replicated plantings of 584 accessions representing 34 Medicago species. These nurseries were planted in the spring of 1981 and data were collected through the 1983 growing season. Most of the species were easily established at both test sites. Many grew more rapidly during the seeding year than did the perennial check, M. falcata L. However, no annual or biennial species was as well nodulated or reduced acetylene on a per plant basis as well as M. falcata. None of the populations matured, reproduced, and initiated soil seed bank at the droughtier of the 2 locations. M. laciniata (L.) Mill., M. lupulina L., M. murex Willd., and M. muricoleptis Tin. excelled in the numbers of seedlings per meter of area established by natural reseeding in the fall of the first year of test. However, only M. lupulina (black medic) produced abundant seedlings during the second year following seeding. Results indicated that M. lupulina could develop a soil seed bank more rapidly than the other species. Black medic also had superior ground cover characteristics during the second and third years after sowing. Adapted populations of M. lupulina appear to have long-term value for forage production in Utah rangeland pastures with suitable soils and adequate precipitation.
    • Combination of Weight Estimates with Clipped Sample Data

      Carande, V.; Jameson, D. A. (Society for Range Management, 1986-01-01)
      Weight estimation is a common procedure to determine range forage production. In this method clipped samples are used to train an observer, to make periodic checks on observer performances, and to compute estimated/clipped conversion factors. The clipped sample data are then discarded. This is in contrast to a double sampling procedure where both clipped values and estimated values are used in computation of sample variance. However, if both estimated values and clipped plots are taken at random, they can be combined to compute sample means and variances by using techniques appropriate to combining data of different variances. The efficiency of the combined sample appears to be greater than that of formal double sampling and also has the advantage that plots clipped for training and checking can also be used as part of the sample.
    • Construction of an Inexpensive Liquid Resin Esophageal Cannula for Goats

      Grünwaldt, E. G.; Sosa, R. (Society for Range Management, 1986-01-01)
      A simple method for construction of esophageal cannulas for goats employing liquid polyestyrenic resin is described. They were made with easily available and low cost materials.
    • Diet of Guanaco and Red Deer in Neuquen Province, Argentina

      Bahamonde, N.; Martin, S.; Sbriller, A. P. (Society for Range Management, 1986-01-01)
      Spring and summer diets of guanaco (Lama guanicoe) and red deer (Cervus elaphus) in northern Patagonia were determined by the microhistological analysis of their droppings. Forbs were the main components of the guanaco diet both in spring and summer. Spring diet of deer was comprised mainly of grasses, whereas the summer was comprised equally of trees, shrubs, forbs and grasses. These results indicate differential use of the area by both species.
    • Dietary Selection by Goats and Sheep in a Deciduous Woodland of Northeastern Brazil

      Pfister, J. A.; Malechek, J. C. (Society for Range Management, 1986-01-01)
      The dietary botanical composition of indigenous sheep and goats was determined in the semiarid tropics of northeastern Brazil, using esophageally fistulated animals. Sheep and goats selected similar diets during the dry season (May-Dec.). Main dietary components for both species were dried forbs and browse. Leaf litter from the deciduous trees provided the majority of dry season forage (500-1,500 kg/ha) and was a crucial element of dry season diets (20-70%). During the wet season (Jan.-Apr.), sheep selected mainly grasses and forbs, while goats rapidly shifted among grasses, forbs, and browse. By displaying attributes of both browsers and grazers, neither sheep nor goats conformed to traditionally rigid characterization. We found no indication that goats are better adapted for survival in this tropical environment than are sheep because of the botanical composition of their diets. Management implications of this study for the caatinga vegetation zone are discussed.
    • Early Root and Shoot Elongation of Selected Warm-Season Perennial Grasses

      Simanton, J. R.; Jordan, G. L. (Society for Range Management, 1986-01-01)
      Root length and root:shoot ratios are considered to be important survival factors of seedlings growing in areas of limited water. This study was conducted to determine early root elongation and root:shoot ratios during the germination to seedling stage of 'Premier' sideoats grama [Bouteloua curtipendula (Michx.) Torr.], 'Cochise' lovegrass (Eragrostis lehmanniana Nees × Eragrostis trichophora Coss and Dur.), 'A-130' blue panic (Panicum antidotale Retz.), and accessions PMT-1733-77 and NM-184 alkali sacaton (Sporobolus airoides Torr.). Root and shoot measurements were made approximately every 12 hr from seed planting to 190 hr and the results related to species success or failure in reported seeding trials. Sideoats grama root lengths were greater than those of all other species at all sample times. Root lengths among the other species were not different until about 5 days after planting when Cochise lovegrass root lengths were significantly (P<0.05) less. Though there was no significant (P<0.05) difference in root lengths among accessions of alkali sacaton, accession 1733 root elongation continued after accession NM-184 root elongation ceased. Sideoats grama shoot lengths were significantly (P<0.05) greater than those of all species until day 6, when sideoats grama and blue panic were not different. Average 7-day root:shoot ratios ranged from 2.9:1 for sideoats grama to 1.3:1 for blue panic. Rapid root elongation or comparatively high root:shoot ratios obtained for species in this study could not be directly related to reported success or failure in seedling establishment.
    • Effects of Adenosine Monophosphate on Germination of Forage Species in Salt Solutions

      Undersander, D. J. (Society for Range Management, 1986-01-01)
      Seed germination can be a limiting step in the establishment of plant species on saline soils. There are indications that the level of adenosine monophosphate (AMP) in the seed may be a limiting factor in seed germination under stress. The objective of this research was to determine if added AMP would improve germination of grass and legume seeds under saline conditions. The seeds of tall fescue (Festuca arundinaceae Schreb. 'K-31'), bluegrama [Bouteloua gracilis (H.B.K.) Lag. ex Steud.], crested wheatgrass [Agropyron cristatum (L) Goertn 'Nordan'], switchgrass (Panicum virgatum L. 'Blackwell'), perennial ryegrass (Lolium perenne L. 'Lynn'), tall wheatgrass [Agropyron elongatum (Host) uv. 'Platte'], Russian wildrye (Elymus junceus Fisch.), western wheatgrass (Agropyron smithii Rydb.), and alfalfa (Medicago sativa L. 'Dawson') were germinated in petri dishes at varying levels of salinity with and without AMP. Time required for germination was shortened for all species, except switchgrass and western wheatgrass, with added AMP. Percent germination of alfalfa was increased with AMP at 14 days in 0.068 M sodium chloride and of tall fescue in the same concentration of sodium sulfate (dibasic). Perennial ryegrass, Russian wildrye and alfalfa demonstrated similar responses at 0.102 M sodium chloride. The germination of alfalfa was improved with AMP at 14 days in 0.034 M sodium sulfate. Adenosine monophosphate tended to have little effect when severe germination depression occurred from high salt concentrations.
    • Effects of Cattle Grazing on Mule Deer Diet and Area Selection

      Austin, D. D.; Urness, P. J. (Society for Range Management, 1986-01-01)
      Split enclosures, half grazed and half ungrazed by cattle in summer, were compared for mule deer habitat use in late summer using tame deer. Diet composition, dietary nutrition, and area selected for grazing by mule deer were used as criteria to assess the grazing effects of cattle. Generally few dietary or nutritional differences were determined. Nonetheless, deer preferred to forage on areas ungrazed by livestock at low deer use levels, but this preference rapidly decreased as deer use increased.
    • Estimating Ratios of Live and Dead Plant Material in Clipped Plots

      Johnson, M. K. (Society for Range Management, 1986-01-01)
      Hand separation of live and dead material from clipped plots is tedious and relatively expensive. Live and dead plant materials are easily distinguished under a microscope and can be quickly quantified. After clipping and drying, a sample can be separated in about 10 minutes.
    • Evaluation of Total Fecal Collection for Measuring Cattle Forage Intake

      Holechek, J. L.; Wofford, H.; Arthun, D.; Galyean, M. L.; Wallace, J. D. (Society for Range Management, 1986-01-01)
      Conventional digestibility trials with steers were conducted to evaluate relationships between actual forage intake and estimated forage intake using the total fecal collection procedure. Actual forage intake of 6 of the 9 forages fed was not accurately estimated by the widely used technique of dividing total fecal output by forage indigestibility estimated by in vitro procedures. This was because 48-h in vitro digestibility poorly estimated in vivo digestibility of 6 forages. Regression equations based on in vivo-in vitro digestibility relationships can reduce but not solve this problem because in vivo processes such as mastication and rumination are bypassed with in vitro techniques. The use of a 36-h microbial digestion period for nongrasses and a 72-96-h microbial digestion period for grasses shows potential to improve in vitro digestibility estimates of cattle in vivo digestibility. Another potential means of improving in vitro digestibility estimates is to select the highest digestibility value from forage or diet samples subjected to 36-, 48-, 60-, 72-, 84- and 96-h microbial digestion periods.
    • Forage Utilization Cost Differentials in a Ranch Operation: A Case Study

      Torell, L. A.; Godfrey, E. B.; Nielsen, D. B. (Society for Range Management, 1986-01-01)
      The total cost (fee and non-fee) of grazing BLM, FS, and private deeded rangeland was estimated by partial budgeting procedures from records kept by the Saval Ranch, a northeastern Nevada cow-calf operation. Private rangeland was estimated to be the most expensive forage source at $24.99 per AUM. The total cost of grazing BLM land was estimated to be $8.07 per AUM and FS was estimated to cost $9.08 per AUM.
    • Germination of Fourwing Saltbush Seeds: Interaction of Temperature, Osmotic Potential, and pH

      Potter, R. L.; Ueckert, D. N.; Petersen, J. L.; McFarland, M. L. (Society for Range Management, 1986-01-01)
      Establishment of shrubs and other forage plants on arid and semiarid rangelands and salt-contaminated sites may be enhanced if ecotypes with ability to germinate and establish under moisture stress and high temperatures can be identified. The interactive effects of temperature, osmotic potential, and pH on germination were evaluated with seed from 4 populations of fourwing saltbush [Atriplex canescens (Pursh) Nutt.] from western Texas. Predicted optimum temperature (15 to 18 degrees C) from osmotic potential by temperature response surfaces for germination of 3 populations (Valentine, Grandfalls, and San Angelo) were similar to those reported for populations of fourwing saltbush from other western states. Germination of seed collected near Texon, Texas was significantly (P<0.01) affected by media pH range 6 to 9. Seed from the Texon population germinated under lower osmotic potentials compared to the other 3 populations. Total germination of all four populations was enhanced by osmotic potentials lower than 0 MPa. Seed from the Texon population may possess germination characteristics more suitable for arid-land seeding than those from populations near Valentine, Grandfalls, and San Angelo, Texas.
    • Grazing Preferences of Cattle in Regenerating Aspen Forest

      Fitzgerald, R. D.; Hudson, R. J.; Bailey, A. W. (Society for Range Management, 1986-01-01)
      The relative preferences of cattle for the major plant species in regenerating aspen (Populus tremuloides) forest following burning were studied to assist in developing strategies for controlling aspen regrowth by grazing with cattle. The tendency of cattle to graze forest rather than grassland increased as grasses matured towards the end of the growing season. Within the forest, cattle preferred herbaceous species when they were present. Of the shrub species, generally wild rose (Rosa spp.) and wild raspberry (Rubus strigosus) were preferred over aspen but aspen was preferred over western snowberry (Symphoricarpos occidentalis). Aspen was grazed more readily late in the season than early. Similarly western snowberry, which was of consistently low acceptability, was relatively more acceptable late in the season. Cattle readily consumed wild raspberry in both years and both seasons. Wild rose was accepted early in the season in both years but was less preferred late in the season when it had relatively more woody growth.
    • Herbaceous Biomass Dynamics and Net Primary Production Following Chemical Control of Honey Mesquite

      Heitschmidt, R. K.; Schultz, R. D.; Scifres, C. J. (Society for Range Management, 1986-01-01)
      The effect of honey mesquite (Prosopis glandulosa var. glandulosa Torr.) control on herbaceous growth dynamics, forage production, and root and crown biomass was investigated in 1979 and 1980 on a site aerially treated with a 1:1 mixture of 2,4,5-T plus picloram at 0.6 kg/ha in May 1974. Density, height, and canopy of honey mesquite trees 5 years after treatment were 248 plants/ha, 0.9 m, and 3.1%, respectively, compared to 963 plants/ha, 2.2 m, and 34.6%, respectively, in the adjacent untreated control plot. Yet, there were no differences between sprayed and untreated plots after 6 and 7 growing seasons relative to species composition, growth dynamics, and production of herbaceous plants. Averaged across years and treatments, estimated aboveground net primary production was 2,525 kg/ha. Crown and root biomass in the top 10 cm of the soil profile averaged 685 and 3,837 kg/ha, respectively, with no significant treatment or year effects. Lack of treatment difference partially validates a conceptual model presently used for economic analysis of herbicide sprays for honey mesquite control. Further, it supports the hypothesis that honey mesquite trees provide critical habitat for the more productive midgrasses indigenous to this site; and that elimination of this habitat in sparse stands of the shrub subsequently limits post-treatment herbage response.
    • Modeling Evapotranspiration from Sagebrush-Grass Rangeland

      Wight, J. R.; Hanson, C. L.; Cooley, K. R. (Society for Range Management, 1986-01-01)
      Three models, CREAMS, SPAW, and ERHYM, were used to predict evapotranspiration (ET) from a sagebrush-grass range site in southwest Idaho. Model-predicted ET was compared with ET measured by a lysimeter and ET calculated with a water-balance equation using field-measured soil water and precipitation values. There was generally good agreement between the lysimeter and water-balance calculated ET and between these ET values and model-predicted ET. Maximum averaged daily ET rates were about 2.5 mm for April, May, and June with single day ET values from the lysimeter as high as 5.0 mm. Although the CREAMS predicted ET rates were generally higher than those predicted by SPAW and ERHYM or measured by the water-balanced method, all 3 models were functionally capable of simulating ET from sagebrush-grass range sites. ERHYM was the simplest of the 3 models to operate.
    • Nutrient Content of Sheep Diets on a Serpentine Barrens Range Site

      Rosiere, R. E.; Vaughn, C. E. (Society for Range Management, 1986-01-01)
      Nutritional composition of sheep diets from a serpentine barrens range site was determined at various seasons and stages of plant growth and compared to diets from 3 other annual range sites. Sheep diets from the serpentine site tended to be more nutritious, ranking in the highest pair of sites in digestibility, digestible energy, crude protein, and ether extract, and containing highest concentrations of magnesium. These differences were subtle and had limited application to management. Nutritional differences attributable to plant phenology were inconsistent but more dramatic than those due to site. Late summer and winter were potentially critical periods for brood ewes with protein and energy, respectively, likely to be marginal or possibly deficient. Contents of nutrients and nutritional properties did not differ between available herbage and forage selected by sheep from serpentine barrens.
    • Observations on Herbage Growth, Disappearance, and Accumulation Under Livestock Grazing

      Scarnecchia, D. L.; Kothmann, M. M. (Society for Range Management, 1986-01-01)
      Expressing the effects of grazing animals on herbage requires explicitly defined variables describing herbage growth and herbage disappearance, as well as variables describing net changes in herbage. This paper presents a mathematical framework on variables describing herbage growth, disappearance, and accumulation, which can be used to model herbage dynamics, and to develop and present field research.