• 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.
    • 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.
    • 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.
    • Relationships among Soluble Phenolics, Insoluble Proanthocyanidins and Fiber in East African Browse Species

      Reed, J. D. (Society for Range Management, 1986-01-01)
      Tannins and other phenolics interfere with the interpretation of results from the detergent system of forage analysis. Leaves and apices from browse can contain up to 50% of their organic matter as phenolics including tannins that are soluble in aqueous acetone. Leaves and apices from browse that contain soluble proanthocyanidins (condensed tannins) also contain proanthocyanidins that are insoluble in both aqueous acetone and neutral-detergent. The content of insoluble proanthocyanidins is positively correlated with neutral-detergent fiber (NDF) and fiber-bound nitrogen. Condensed tannins may bind protein and make it less soluble in neutral-detergent and increase the content of NDF. The behavior of phenolics and tannins in the detergent system of forage analysis is discussed in relationship to estimating the nutritive value of 17 East African browse species.
    • Relationships of the Error Associated with Ocular Estimation and Actual Total Cover

      Hatton, T. J.; West, N. E.; Johnson, P. S. (Society for Range Management, 1986-01-01)
      The relationship between the error associated with the ocular estimation of cover and the magnitude of actual cover was examined by estimation of artificially constructed images of known cover under laboratory conditions. Estimation error varied with actual cover in a manner suggesting that cover classes should be relatively narrow at the extremes of actual cover.
    • Renovation of Seeded Warm-season Pastures with Atrazine

      Dill, T. O.; Waller, S. S.; Vogel, K. P.; Gates, R. N.; Stroup, W. W. (Society for Range Management, 1986-01-01)
      Numerous warm-season pastures have been established in the last 30 years in the central Great Plains. Some of these pastures are old enough to verify that they can be abused by overgrazing as easily as native tallgrass prairies. Overgrazed warm-season pastures are invaded and dominated by cool-season grasses such as smooth brome (Bromus inermis Leyss.) and Kentucky bluegrass (Poa pratensis L.), which diminishes the pasture productivity during the hot summer months. Since established warm-season grasses have greater tolerance to the herbicide atrazine than cool-season grasses, the effectiveness of atrazine applications in renovating invaded warm-season pastures was evaluated. A single, early spring application of atrazine (3.3 kg/ha) killed or sufficiently suppressed the cool-season grasses so that surviving warm-season remnants were able to effectively re-establish the warm-season pasture in a single growing season without any loss in total pasture forage production. Lower rates of atrazine were not as effective, particularly if smooth brome was the primary cool-season grass. The single atrazine application cost was approximately 25% of the seed cost associated with more conventional renovation. Pastures should not be grazed the treatment year but can be hayed at the end of the growing season. The success of the practice is dependent on the presence of warm-season grass remnants. Spraying test strips in small fenced areas would be advisable before treating entire pastures.
    • 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.
    • Phytosociological Observations on the Vegetation of Burnt and Unburnt Areas Near Ibadan, Nigeria

      Sharma, B. M. (Society for Range Management, 1986-01-01)
      The area of study has a topography mainly of plains with occasional hills and is characterized by comparatively higher pH and conductivity on burnt sites. The weed communities existing on the unburnt sites were Axonopus-Eupatorium-Centrosema Community during the dry season (November to March) and Axonopus-Eupatorium-Commelina Community during the wet season (April to October). However, on the burnt sites, Imperata-Setaria-Panicum Community emerged. The dry season community on the unburnt site had comparatively the highest diversity index. Index of species association was high for Imperata cylindrica and Calapogonium mucumoides on burnt sites while for Axonopus compressus and Commelina diffusa during both dry and wet seasons on unburnt sites. The sominance-diversity relationships based on Simpson's Index were higher for the community on burnt sites. According to Kuchler's height classes, the height class 2 was predominant. The annual vegetation burning, in general, results in a preponderance of grasses and there were 12 grasses out of 29 species (41.4%) recorded on the burnt areas.
    • Population Dynamics of Seeded Species on Northeast Washington Semiarid Sites, 1948-1983

      Harris, G. A.; Dobrowolski, J. P. (Society for Range Management, 1986-01-01)
      Fifty-one graminoid and 10 forb taxa commonly used in range seedings were planted at 3 semiarid northeast Washington sites, spring and fall seasons, in monospecific stands, on 5.5 m by 1.3 m plots, 1948 to 1951. Population dynamics and clipped yields were observed at irregular intervals from 1952 to 1983. Ten graminoid, but no forb, taxa are recommended for range seeding. Grass species differ markedly in fitness for the sites, as demonstrated in success of passing through the environmental sieve, recruiting posterity, and long-term survival. Species interactions were site specific, demonstrating characteristic and complex demographic schedules at each site. Hard fescue was the most aggressive competitor, progressively replacing many of the others at all sites. Crested wheatgrass taxa provided the highest yields. Species mixtures which developed were unstable in the long term (30 years), and are not recommended in seeding practice.
    • 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.
    • 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.
    • Small Mammals in Modified Pinyon-Juniper Woodlands, New Mexico

      Severson, K. E. (Society for Range Management, 1986-01-01)
      The effects of pinyon (Pinus edulis)-juniper (Juniperus spp.) treatments on rodent abundance, 13 to 18 years after treatment, were studied in southwestern New Mexico from 1981 to 1983. Treatments included bulldozing, bulldozing/piling/burning, thinning, and untreated woodland. The area had not been grazed by livestock since time of treatment but was subjected to light and irregular use by wild ungulates. Total rodent numbers were significantly greater (P is greater than or equal to 0.05) on all treated areas compared to untreated woodlands but individual species and groups responded differently. Woodrats (Neotoma spp.) and brush mice (Peromyscus boylii) increased in abundance as slash accumulations increased, regardless of condition of overstory. Pinyon mice (P. truei) and rock mice (P. difficilus) numbers were also greater where slash was present, but only if the pinyon-juniper overstory was relatively intact. Grassland rodents, as a group, were more abundant on areas where the pinyon-juniper overstory and slash had been removed (bulldozed and bulldozed/piled/burned), but reduced numbers on bulldozed plots where slash was left suggested slash accumulations may have detrimental effects on numbers of these species. Treatments did not influence number of different rodent species. Data indicate that numbers of individuals and proportions of rodent species can be affected by manipulation of pinyon-juniper overstory and method of slash disposal.
    • 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.
    • 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.
    • 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.
    • 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.