• A Comparison of Four Methods Used to Determine the Diets of Large Herbivores

      McInnis, M. L.; Vavra, M.; Krueger, W. C. (Society for Range Management, 1983-05-01)
      Esophageal fistulation, stomach content analysis, fecal analysis, and forage utilization were compared as techniques for determining food habits of large herbivores. Each technique was evaluated based upon information collected using bi-fistulated (esophageal and rumen) sheep during 2 study phases. In the first study phase, microscope slide mounts were made of plant fragments collected from the esophagus, rumen, and feces of 10 confined sheep fed a hand-composited mixture of forage. Dietary composition as determined by each technique was compared to the original feed. Stomach content analysis and fecal analysis produced dietary estimates higher in grasses and lower in forbs than the known feed values. Esophageal fistulation results were not significantly different from the known feed values. In the second study phase, esophageal, rumen, and fecal collections were gathered from 16 sheep grazing a common plant community. Ocular estimates of forage utilization were made concurrently. All data were converted to percent composition on a dry weight basis for comparisons. Significant differences in percent diet composition among techniques occurred for 18 of the 31 plant species consumed. Diets determined by stomach content analysis and fecal analysis were significantly higher in grasses and lower in forbs than those determined by esophageal fistulation and ocular estimates of utilization.
    • An Improved Method for Attaching the Esophageal Fistula Bag

      Kartchner, R. J.; Adams, D. C. (Society for Range Management, 1983-05-01)
      A simple, surgically established skin "neck loop" was tested for holding the collection bag in position on esophageal fistulated steers. The loop eliminated the need for a girth strap and reduced the time required for attaching and detaching the collection apparatus.
    • Attentiveness of Guarding Dogs for Reducing Predation on Domestic Sheep

      Coppinger, R.; Lorenz, J.; Glendinning, J.; Pinardi, P. (Society for Range Management, 1983-05-01)
      Dogs used to protect domestic sheep from predators are expected to be attentive to the animals they guard. However, 40% of the sheep producers cooperating in our experimental program to assess the potential of Old World dogs to deter predation in the United States have expressed dissatisfaction with their dog's attentiveness. In contrast, European shepherds appear satisfied with their dogs. In order to find the causes of this apparent difference, a series of measured observations was made in Italy, and data on 4 different strains of imported guarding dogs working in the U.S. were analyzed. The results indicate that the 4 strains are significantly different in attentiveness, although overall it was remarkably similar to the actual attentiveness of Italian dogs. The attentiveness of livestock guarding dogs can be maximized for U.S. sheep producers by (1) selecting strains for superior attentive behavior and (2) adjusting management systems slightly to take advantage of the dogs' capabilities.
    • Cattle Trampling of Simulated Ground Nests under Short Duration and Continuous Grazing

      Koerth, B. H.; Webb, W. M.; Bryant, F. C.; Guthery, F. S. (Society for Range Management, 1983-05-01)
      Trampling by cattle on simulated ground nests were compared between continuous (CONT) grazing at 8.0 ha/steer and short duration grazing (SDG) at 5.3 ha/steer. Trampling losses were similar under CONT grazing (15%) and SDG (9%) at a nest density of 1/ha. Percentage trampling loss did not increase at higher nest densities under either grazing regime. Nest survival curves indicated a loss rate of 2.21%/wk under CONT grazing and 2.09%/wk under SDG. The data from this study suggest there is no reason for concern that SDG with cattle will increase trampling loss of ground nests over CONT grazing.
    • Distribution of Dry Matter and Chemical Constituents in Plant Parts of Four Florida Native Grasses

      Kalmbacher, R. S. (Society for Range Management, 1983-05-01)
      Because of the selective nature of grazing livestock, the use of whole plant samples to estimate the nutritional potential of forages may be misleading. During this 2-year study, the distribution of dry matter (DM), crude protein (CP) in vitro organic matter digestibility (IVOMD), and concentrations of P, K, Ca, Mg, Mn, Fe, Cu, and Zn were determined in the individual leaf blades, leaf sheaths, nodes plus internodes, and infloresences of creeping bluestem (Schizachyrium stoloniferum), lopsided indiangrass (Sorghastrum secundum), maidencane (Panicum hemitomon), and wiregrass (Aristida stricta) when they were in the anthesis stage of maturity. Most of the DM was in the nodes plus internodes (avg. 45%), while the leaf blades (avg. 18%) generally made up the smallest amount of the total plant DM. In a progression from the bottom to top of the plant the CP, IVOMD, and most of the mineral concentration of the different leaf blades, sheaths, and nodes plus internodes increased. Crude protein, IVOMD, and most of the minerals of the grasses were higher in leaf blades, followed by sheaths, and nodes plus internodes. When compared with other grasses, maidencane had a higher proportion of CP and minerals in the leaves and nodes plus internodes and a higher percentage of plant weight in these parts. Wiregrass was found to be similar to creeping bluestem and indiangrass in CP and most minerals, but IVOMD of wiregrass parts were lower. Dietary requirements for dry, pregnant cows for P, N, Mg, and Cu might not be met by any part of the 4 grasses, while apparently adequate levels of Fe, Mn, and Zn could be provided by each part. Leaf blades and infloresences had sufficient Ca concentrations for dry pregnant cows.
    • Ecological Characteristics and Control of Gambel Oak

      Engle, D. M.; Bonham, C. D.; Bartel, L. E. (Society for Range Management, 1983-05-01)
      Manipulation of Gambel oak for enhanced rangeland values must be in accord with ecological principles to ensure desired success. Failures in controlling Gambel oak have occurred because the growth patterns, morphological characteristics, and carbohydrate storage patterns of the species have not been taken into account. However, recurrent control will continue to be necessary since grass dominated systems should not be considered to be climax in Gambel oak dominated systems. Existing initial and maintenance control methods appear to offer only short-term solutions, which often result in more troublesome long-term management problems.
    • Economics of Gypsum and Elemental Sulfur as Fertilizers on Subclover-Grass Pastures in Northern California

      Center, D. M.; Jones, M. B. (Society for Range Management, 1983-05-01)
      Sulfur deficiencies are widespread on the rangeland soils of California and the application of sulfur-bearing fertilizers has been widely recognized as a promising range improvement on these soils. Considerable work has been done on the management and ecological aspects of sulfur fertilization of California rangeland; however, little or no economic analysis of this improvement exists. Using existing data from subclover-grass pastures in northern California to derive aggregate production functions, optimal application rates of sulfur applied as elemental sulfur and gypsum were determined using standard marginal analysis. Both elemental sulfur and gypsum proved to be profitable means of increasing both winter and total yearly production when either harvested hay or grazed forage (AUM's) were considered as products. Using 1981 material costs and product prices applied to total yearly hay production, the optimum rate of sulfur applied as gypsum with 3 years residual was 251 kg/ha for an increased profit of $101/ha/yr over unfertilized pastures. The optimum rate of elemental sulfur was 147 kg/ha for a profit increases of $93/ha/yr. When total yearly grazed forage was considered the product, optimum application rates were 195 kg/ha of sulfur as gypsum and 126 kg/ha for elemental sulfur yielding profit increases of $46/ha/yr and $48/ha/yr, respectively. Optimal application rates and profits were lower for both hay production and grazed forage when winter production was optimized.
    • Effect of Soil Contamination on the Mineral Composition of Forage Fertilized with Nitrogen

      Mayland, H. F.; Sneva, F. A. (Society for Range Management, 1983-05-01)
      Mineral analysis of forage from a nitrogen (N) fertilizer, field study produced unexpectedly high iron (Fe) concentrations which were correlated with the N fertilizer level (r2=.92) and the percentage N in the forage (r2=.94). The high Fe values were presumed to be associated with dust on the leaves. The objective of this study was to determine the level of soil contamination on the forage sample and the contribution of mineral in the contaminant to that measured in the sample. Soil contamination of plant tissue samples was calculated from the dilution of soil titanium (Ti) assuming that the uncontaminated tissue contained 0 g Ti/g. Tissue harvested from the 0, 28, 56, or 84 kg N/ha treatments contained 23, 49, 48, and 60 mg soil/g, respectively. Significant N fertilizer effects would have been accepted for each element tested if soil contamination had been ignored. Correcting for contamination resulted in significant N-fertilizer effects on the concentrations of sodium, potassium, manganese, iron, and zinc but not magnesium or calcium in the forage. Some of these effects may be explained by the acidifying effect of the N fertilizer source.
    • Effect of Weedy Annuals on the Survival and Growth of Transplants Under Arid Conditions

      Van Epps, G. A.; McKell, C. M. (Society for Range Management, 1983-05-01)
      A plant establishment study was conducted in the oil shale region of northeastern Utah where annual rainfall averages 200 mm. Treatments consisted of annual weed removal for 2 years, for 1 year, and no removal to test the impact of competition on survival of bareroot and container-grown transplants. Competition had a major negative effect on the survival and growth of fourwing saltbush (Atriplex canescens), winterfat (Ceratoides lanata), prostrate summer cypress (Kochia prostrata), and russian wildrye (Elymus junceus). At the end of 4 growing seasons only 21% of the plants survived under normal site competition compared to 84% survival with 2 years of weed removal. The area of plant canopy under the influence of full competition averaged 0.95 dm2 as compared with 4.03 dm2 where competition was absent for 2 years for the same period.
    • Effects of Annual Applications of Low N Nitrogen Fertilizer Rates on a Mixed Grass Prairie

      Rauzi, F.; Fairbourn, M. L. (Society for Range Management, 1983-05-01)
      Nitrogen (N) fertilizer at rates of 0, 22, and 34 kg/ha was applied annually in the spring or fall over a 5-year period to a mixed grass prairie. Major species present were blue grama (Bouteloua gracilis), western wheatgrass (Agropyron smithii), and dryland sedges (Carex Sp.). Slim leaf goosefoot (Chenopodium leptophyllum) and other annual and perennial forbs were also present. Total herbage production, crude protein content, mineral concentrations, species composition and water use data were collected. Total herbage yields and crude protein from all the fertilizer treatments were significantly greater as compared with the control. Nearly all of the variation in phosphorus (P), calcium (Ca), potassium (K), and magnesium (Mg) concentrations and species composition were associated with the seasonal distribution of precipitation (years) and not with N-fertilization treatments.
    • Evaluation of a Fertilized 3-Pasture System Grazed by Yearling Steers

      Nyren, P. E.; Whitman, W. C.; Nelson, J. L.; Conlon, T. J. (Society for Range Management, 1983-05-01)
      A grazing trial comparing fertilized and unfertilized 3-pasture systems has shown that the addition of 56 kg nitrogen (N)/ha substantially improved forage and beef production. Forage production from the fertilized system was increased by 46% over the unfertilized system while per acre beef gains were increased 35%. Each 3-pasture system utilized crested wheatgrass for spring and early summer, native mixed grass prairie for mid and late summer and Russian wildrye for fall grazing. Comparison of Hereford and Angus-Hereford crossbreds indicated a slight gain advantage for the crossbred animals, although the increase was not statistically significant. The addition of the biuret supplement Kedlor was found to improve gains of steers grazing the native pastures in late summer but resulted in decreased gains on fall-grazed Russian wildrye pastures. Analysis of the forage samples showed that in all samples except one, the addition of N fertilizer increased the protein content.
    • Fire History at the Forest-Grassland Ecotone in Southwestern Montana

      Arno, S. F.; Gruell, G. E. (Society for Range Management, 1983-05-01)
      The history and influence of fires was studied at the forest-grassland ecotone in high valleys of southwestern Montana. Investigations were focused upon several sites having early landscape photographs and modern retakes that allow for detection of vegetational changes. Fire intervals were determined for these sites by analyzing fire scars on trees. Prior to 1910, mean fire intervals at Pseudotsuga forest-grassland ecotones were 35 to 40 years, and probably shorter in grassland proper. No fires were detected on the study areas after 1918. Photographic comparisons and field inspections show a substantial increase in mountain big sagebrush (Artemisia tridentata subsp. vaseyana) and conifers since 1900.
    • Fire-Induced Mortality of Redberry Juniper [Juniperus Pinchotii Sudw.]

      Steuter, A. A.; Britton, C. M. (Society for Range Management, 1983-05-01)
      Redberry juniper mortality was determined following spring broadcast burns in 1979 and 1980, and individual-plant burns with 3 heat treatments in 1981. Mortality varied from 1 to 100% and was related to bud zone location, plant size, site, and growing conditions. During years of above average precipitation, mortality averaged 70% for plants with the bud zone above the soil surface contrasted to 3% for plants with the bud zone partially below the soil surface. Plant size and site factors such as slope and soil surface stability appeared to affect the rate at which the bud zone was buried by soil, thus producing a fire resistant plant. Plant mortality was significantly increased across all size classes and sites when burns were conducted under hotter conditions and followed by a dry growing season.
    • Fistula Sample Numbers Required to Determine Cattle Diets on Forest and Grassland Ranges

      Holechek, J. L.; Vavra, M. (Society for Range Management, 1983-05-01)
      The variation among esophageal fistulated (EF) cattle in diet nutritive content and botanical composition selection was evaluated on forest and grassland range in the Blue Mountains of eastern Oregon during the summer of 1976. Botanical composition of diet samples was determined with microhistological analysis. Nutritive value was evaluated by analyses for crude protein, acid detergent fiber, permanganate lignin, and in vitro organic matter digestibility. Four collections were made from 4 EF heifers during each of 4 28-day periods on each vegetation type. Collections were alternated between morning and afternoon on each vegetation type. EF cattle selected diets of different (P<.05) botanical composition and nutritive quality in the early morning compared with the late afternoon. They grazed open grassland areas in the morning and shaded areas in the afternoon. Several more EF cattle and collections were required to determine diet botanical composition than nutritive quality on both the forest and grassland. A minimum of 4 EF cattle and 4 collections were needed to adequately sample diet nutritive characteristics on the grassland and forest pastures. The data indicated collections should be rotated between morning and afternoon on ranges supporting a mosaic of grassland and forest plant communities.
    • Food Habits of Nilgai Antelope in Texas

      Sheffield, W. J. (Society for Range Management, 1983-05-01)
      A 2-year food habit study of the nilgai antelope (Boselaphus tragocamelus) and its forage selections compared with white-tailed deer (Odocoileus virginianus) and cattle was conducted in south Texas. Rumen analyses of 79 nilgai and 40 deer, collected on various feeding sites, and bite studies on the same sites using two captive nilgai and a trained steer showed no significant difference (P>0.05) in forage classes taken between the 2 methods. Nilgai preferred to feed on large open areas interspersed with cover and ponded water. They were grazers, their average diet consisting of 60% grasses, 25% forbs, and 15% browse. They augmented the nutritive level of their basic diet by selecting nutritious plant parts and changing their selections as the parts appeared, waned, and fluctuated in quality with the seasons. When food was scarce, nilgai ate more browse, dead vegetation, and dry dung of large herbivores. The quality and quantity of their forage was within the levels published for cattle and North American big game. They maintained a feeding role intermediate between cattle, which used mainly grass, and deer, which used forbs heavily. When food supply and variety was low, nilgai competed strongly with cattle for grass and deer for forbs. The 3 species seem compatible where there is good variety of browse and herbage, and control of their respective numbers.
    • Fuel-Load Reductions Resulting from Prescribed Burning in Grazed and Ungrazed Douglas-fir Stands

      Zimmerman, G. T.; Neuenschwander, L. F. (Society for Range Management, 1983-05-01)
      Prescribed understory burning was carried out in both grazed and ungrazed Douglas-fir stands on the University of Idaho Experimental Forest. Burning conditions were moderately cool with 10-hr time-lag fuel moisture varying from 11 to 19%. Preburn and postburn fuel loadings were determined by use of the planar intersect method. Preburn data indicated greater fuel accumulations in grazed stands, 55,460 kg/ha, as compared to ungrazed stands, 44,710 kg/ha. Difficulty in achieving a satisfactory rate-of-spread and fire intensity was encountered due to the combined effects of a very dry summer followed by a wet fall. Moist conditions on the study site, lack of fine fuels, and accumulation of heavy fuels in the grazed portion produced a burn of patchy nature. Fire rate of spread varied from 0 to 183 cm/minute with flame height up to 91 cm. Result was a fuel reduction of 60.2% in the grazed stand and 35.2% in the ungrazed stand. Prolonged grazing in this area had created a dense, overstocked stand with insufficient fine fuels to carry a fire, which severely limited the effectiveness of prescribed burning.
    • Germination Requirements of Green Needlegrass (Stipa viridula Trin.)

      Fulbright, T. E.; Redente, E. F.; Wilson, A. M. (Society for Range Management, 1983-05-01)
      Germination requirements of green neddlegrass (Stipa viridula Trin.) were studied because of its potential for use in revegetation of disturbed lands. The effects of temperature, light, physiological, and mechanical treatments on germination of green needlegrass seed from 4 sources were examined to determine requirements for maximum germination and possible causes of dormancy. Optimum temperatures for germination were 20 degrees C (constant) and 20-15 degrees C (16 hr-8 hr alternation). Germination was highest in constant darkness. Greatest germination of the most dormant source occurred when seeds were either prechilled or treated with gibberellic acid and the lemma and palea was clipped with a razor blade. The results indicated that dormancy of green needlegrass seeds was associated with a deficiency of endogenous gibberellins and with mechanical and permeability restrictions imposed by the lemma and palea.
    • Huisache Growth, Browse Quality, and Use Following Burning

      Rasmussen, G. A.; Scifres, C. J.; Drawe, D. L. (Society for Range Management, 1983-05-01)
      Exposure of huisache plants to fire for 5, 10, or 20 sec on Coastal Prairie in June, August, October, or December 1979, and February or April 1980 usually killed canopies of 90% or more of the plants. However, all burned huisache plants sprouted following treatment, regardless of season or intensity of burning. Precipitation, rather than season of treatment appeared to regulate rate of huisache regrowth following burning. Huisache 1 to 2 m tall replaced their original heights by the end of the second growing season after burning. New growth of huisache plants burned in winter contained more crude protein and phosphorus into late summer, than did browse from unburned plants. Differences in crude protein contents between twigs from burned and unburned plants were greatest following significant rainfall; there were no differences during dry periods. Although burning in late August increased number of twigs available for browsing, it did not affect percentage of available huisache twigs which were browsed. Large browsers (white-tailed deer and cattle) and small animals (rodents and lagomorphs) apparently accounted for most browse removal during the first 60 to 90 days postburn. However, insects apparently consumed most of the huisache browse during the growing season following burning in August.
    • Influence of Clay and Organic Matter of Rangeland Soils on Tebuthiuron Effectiveness

      Duncan, K. W.; Scifres, C. J. (Society for Range Management, 1983-05-01)
      Phytotoxicity of tebuthiuron applied at 0.12, 0.25, or 0.5 ppm to 10 different rangeland soils containing huisache in the greenhouse was inversely related with clay and organic matter contents. However, influences of soil properties were greatest at low herbicide dosages and could be masked by increasing tebuthiuron application rate. For example, tebuthiuron at 1 or 2 ppm killed the huisache after 287 days, regardless of soil, whereas 0.12 or 0.25 ppm killed huisache only when applied to soils with less than 15% clay (these soils contained less than 2.5% organic matter). Potential for tebuthiuron phytotoxicity appears to be greatly diminished in soils containing more than 30% clay. Although the effects of organic matter were confounded with soil clay contents in this study, variations in clay content consistently accounted for a greater proportion of variation in huisache response than did organic matter content.