• Alfalfa hay crop loss due to mule deer depredation

      Austin, D. D.; Urness, P. J.; Duersch, D. (Society for Range Management, 1998-01-01)
      To define alfalfa crop loss from depredating mule deer, the spotlight count and paired plot techniques were applied in 12 fields located throughout Utah. Protected and grazed plots were used to determine alfalfa loss. A significant relationship between deer-nights of grazing and alfalfa loss was determined. Based on our studies, we recommend using 2.4 kg/deer-night for mule deer depredation of alfalfa using the spotlight count assessment technique. Nutritional quality of alfalfa was not different between grazed and protected plots.
    • Biological Manipulation of Blackbrush by Goat Browsing

      Provenza, F. D.; Bowns, J. E.; Urness, P. J.; Malechek, J. C.; Butcher, J. E. (Society for Range Management, 1983-07-01)
      Domestic goats were used to modify the growth form of blackbrush, a spinescent shrub occurring in nearly monospecific stands on several million hectares of rangeland in the southwestern United States. The objective of this research was to provide data on the responses of blackbrush, goats, and cattle to a biological manipulation program in which winter goat browsing was used to stimulate spring twig production in an attempt to improve fall and winter range for cattle. Goats were stocked at 4 intensities during each winter from 1977 to 1979. Resultant levels of utilization and spring twig production were determined, with increased utilization leading to increased twig production. Browsing improved the nutritional quality of blackbrush by stimulating twig production, and current season's twigs collected during the winter contained more crude protein (6.5 versus 4.6%), phosphorus (0.10 versus 0.08%) and in vitro digestible dry matter (48 versus 38%) than did older twigs. Cattle (heifers) browsed blackbrush pastures during October of 1979. Heifers in pastures unbrowsed by goats consumed primarily older twigs while those in previously browsed pastures consumed primarily current season's twigs. No statistically significant differences in weight response were recorded for heifers using pastures that were, or were not, previously browsed. In previously unbrowsed pastures, however, the average heifer consumed 1.9 times more protein supplement than did her counterpart in previously browsed pastures.
    • Comparison of In Vivo and In Vitro Dry Matter Digestibility of Mule Deer Forages

      Urness, P. J.; Smith, A. D.; Watkins, R. K. (Society for Range Management, 1977-03-01)
      pIn vivo digestibility percentages from mule deer (Odocoileus hemionus) digestion-balance trials were usually higher than in vitro determinations obtained from the same experimental forage species. Linear regression analysis suggested a correction factor could be applied to in vitro estimates to make them more nearly correspond to in vivo dry matter digestibility values. Forages with in vitro digestibility values below 35% often varied markedly from in vivo estimates. It raises the question whether deer consume species lower than this in digestibility given reasonable choice.
    • Diameter-Length,—Weight Relations for Blackbrush [Coleogyne ramosissima] Branches

      Provenza, F. D.; Urness, P. J. (Society for Range Management, 1981-05-01)
      Regression was used to relate branch diameter to branch length (r = 0.85) and weight (r2=0.94) for blackbrush plants in southwestern Utah. These regression equations were subsequently used to estimate blackbrush utilization by domestic goats in a browsing study. The diameter-length equation compared favorably with before-and-after measurements for accuracy and greatly reduced man-hour costs in determining utilization. Estimates of utilization based on the diameter-weight equation were less than estimates based on the before-and-after approach or the diameter-length equation; the diameter-weight equation accounted for leaves and thus provided a more accurate estimate of utilization.
    • 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 domestic goats on deer wintering in Utah oakbrush

      Riggs, R. A.; Urness, P. J.; Gonzalez, K. A. (Society for Range Management, 1990-05-01)
      Dietary composition and quality, activity budgets, and foraging behavior of tame mule deer (Odocoileus hemionus hemionus) were monitored in winter to ascertain the effects of prior summer use of oakbrush communities by domestic goats (Capra hircus). Reduction of deciduous browse by goats resulted in increased use of Wyoming big sagebrush (Artemisia Nutt. subsp. wyomingensis Beetle and Young) by deer when snow cover precluded use of understory species. As a result, the diets of deer confined to goat-browsed pastures contained less fiber and tannins, and were more digestible than those of deer in control pastures. Digestible protein in diets did not differ. No goat-related effects were observed in the absence of snow because deer grazed the herbaceous understory which had not been substantially altered. Quantity of cured herbage was low, and deer did not effectively select for fall regrowth. Consequently, diet quality under snow-free conditions was not substantially different from that observed under snow-covered conditions. Snow reduced foraging efficiency; deer travelled faster, and exhibited lower bite and intake rates when feeding under snow-covered conditions than under snow-free conditions. Goat-induced vegetal differences were not reflected in activity budgets or foraging behavior, regardless of snow condition. We conclude that goats may be used to periodically manipulate composition of oakbrush winter range, thereby enhancing quality of deer diets under snow-covered winter conditions. However, enhancement of deer diets under snow-free winter conditions probably requires annual manipulation of the understory.
    • Effects of goat browsing on gambel oak communities in northern Utah

      Riggs, R. A.; Urness, P. J. (Society for Range Management, 1989-09-01)
      Replicated populations of 5 shrub species were monitored over a 3-year period to assess community responses to intensive browsing by Spanish-type goats. Response variables included stem density, stem-size distribution skewness, stem diameter-stem production relations, and sprout abundance and weight. No species exhibited a density change. Size distribution skewness increased only in browsed oak (Quercus gambelii Nutt.) populations. Sprout weights also increased in browsed oak populations, but declined in comparably browsed serviceberry (Amelanchier alnifolia Nutt.) populations. The only other significant sprouting response was an increase in sprout numbers in browsed snowberry (Symphoricarpos oreophilus Gray) populations. Relationships between basal stem diameter and stem production of 4 species were altered by goat use. The slopes of these relations were consistently lower in browsed populations of oak and serviceberry than in adjacent control populations, indicating that browsing reduced productivity, especially of large stems. Conversely, slopes of rabbit-brush (Chrysothamnus viscidiflorus lanceolatus (Hook.) Nutt.) relations increased in goat-browsed pastures relative to those of control populations; rabbitbrush was avoided by goats. Similarly, big sagebrush (Artemisia tridentata wyomingensis Nutt.) was avoided and its stem production responded positively in communities subjected to goat browsing. Important cumulative effects of goat browsing included declines in productivity of serviceberry and oak, and an increase in that of sagebrush.
    • Elk forage utilization within rested units of rest-rotation grazing systems

      Werner, S. J.; Urness, P. J. (Society for Range Management, 1998-01-01)
      Elk (Cervus elaphus) have been repeatedly observed to prefer rested units within rest-rotation grazing systems. Given the logistical and financial investments associated with the maintenance of these systems, elk herbivory within rested units is a potential source of conflict. Elk forage utilization was determined during the summers of 1994 and 1995 at the forest-grassland ecotone of 3 rest-rotation grazing allotments in south-central Utah's Fishlake National Forest. Average phytomass within areas protected from and subjected to elk herbivory was not statistically different in June and August 1994. Average phytomass within caged areas was greater (P < 0.20) than that within areas subjected to elk use in 2 of 3 rested units in June-July 1995 (14.1 and 35.6% utilization) and August 1995 (34.7 and 42.0% utilization). June-to-August forage regrowth, however, was 31.3 and 33.0% greater in 1995 than in 1994 within caged and uncaged areas, respectively.
    • Establishing Browse Utilization from Twig Diameters

      Jensen, C. H.; Urness, P. J. (Society for Range Management, 1981-03-01)
      Measurement of twig lengths before and after browsing and measurement of twig diameter after browsing are two techniques to estimate utilization. The two techniques were compared for bitterbrush (Purshia tridentata) and cliffrose (Cowania stansburiana). Utilization percentages determined from the two approaches were highly correlated. However, regression equations were not required to estimate utilization from the diameter measurements alone. Correction factors were obtained by subtracting the twig tip diameter of unbrowsed twigs from diameter at the browsed tip and from basal diameter; then dividing the corrected browsed-tip diameter by the corrected basal diameter and multiplying by 100. By using the correction factor, valid estimates of percentage utilization were obtained. The numerical value for twig-tip diameter can be obtained from measuring twig tips of a representative number of unbrowsed twigs. Estimating utilization from twig diameter has two major advantages: (1) accurate estimates of utilization can be reconstructed from postbrowsing measurement alone and (2) making a single annual visit to the rangeland can represent a considerable time saving.
    • Habitat Selection, Foraging Behavior, and Dietary Nutrition of Elk in Burned Aspen Forest

      Canon, S. K.; Urness, P. J.; DeByle, N. V. (Society for Range Management, 1987-09-01)
      Prescribed burning is frequently used to enhance regeneration of aspen. The effects of burning aspen on wild ungulates are poorly understood. We used free-ranging tame elk to assess diet composition and quality on a site containing a 40-ha aspen burn, pure unburned aspen, mixtures of aspen and conifers, and other habitats. Foraging preferences of elk among the habitats were also investigated. Overall, no dietary nutritional differences were found between burned and unburned aspen habitats. Diet composition by forage class varied somewhat, due primarily to an abundance of very palatable post-fire forbs on the burn. Time spent feeding was significantly different among habitats. The burn was substantially more attractive for foraging probably because preferred forages were consistently available and greater foraging efficiency was possible than in other habitats.
    • Impacts of mule deer and horse grazing on transplanted shrubs for revegetation

      Austin, D. D.; Urness, P. J.; Durham, S. L. (Society for Range Management, 1994-01-01)
      Revegetation success on foothill ranges in northern Utah using big sagebrush (Artemisia tridentata Nutt. spp. wyomingensis Beetle and Young) and rubber rabbitbrush brush (Chrysothamnus nauseosus Britt. spp. albicaulis H. and C.) was determined as influenced by winter mule deer browsing and spring horse grazing. Treatment areas of 0.1 ha with 3 replications included a protected control, use by deer only, use by horses only, use by deer and horses, and use by deer with horse grazing delayed for 3 years after seedling transplant. Results from the first 6 growing seasons following transplanting of seedlings showed grazing by horses only tripled the available, per-plant browse production of big sagebrush compared to protected plots, whereas browsing by deer only resulted in a 40% decrease in browse production. Seedling survival of big sagebrush differed between treatments during the first 3 growing seasons but was not affected by grazing after the third growing season. Rubber rabbitbrush was not affected by treatments.
    • Nutritional Value of Crested Wheatgrass for Wintering Mule Deer

      Urness, P. J.; Austin, D. D.; Fierro, L. C. (Society for Range Management, 1983-03-01)
      The nutritional value of crested wheatgrass in the fall to spring diet of mule deer was determined from in vivo and in vitro digestibilities, a field grazing trial, and crude protein analyses. Its dietary significance was evaluated by comparing the known diet with and without the grass component. Findings indicated fall regrowth and spring growth of crested wheatgrass favorably affected the nutritional plane of mule deer on winter range dominated by big sagebrush having intermingled seedings of this exotic grass.
    • Nutritional value of fresh Gambel oak browse for Spanish goats

      Dick, B. L.; Urness, P. J. (Society for Range Management, 1991-07-01)
      Little information is available on the nutritional value of fresh browse for ruminants. This study examined the nutritive value of Gambel oak (Quercus gambelii Nutt.) for Spanish goats. Fresh Gambel oak browse was harvested at 2 phenological stages and mixed with chopped alfalfa hay to formulate 6 diets, varying in oak content. Diets included 95% juvenile oak/5% alfalfa (95J), 80% juvenile oak/20% alfalfa (80J), 65% juvenile oak/35% alfalfa (65J), 80% mature oak/20% alfalfa (80M), 40% mature oak/60% alfalfa (40M), and an alfalfa control (ALF). Diets were evaluated for goats using a series of digestion-balance trials, in a completely randomized design. Dry matter intake was highest (P < 0.01) for animals on diets with mature oak (80M-37.8, 40M-34.5 grams kg-1 day-1, and lowest on diets containing juvenile oak (95J-23.6, 80J-31.6, 65J-29.9 grams kg-1 day-1). Digestibility of dry matter and cell wall components was lower (P < 0.01) for mature oak diets, and higher for juvenile oak diets. Digestibility coefficients for dry matter were as follows: (80M-57.8%, 40M-58.8%, 95J-68.6%, 80J-65.3%, 65J-66.3%. Digestibility coefficients for cell wall were: 80M-33.1%, 40M-37.4%, 95J-53.7%, 80J-45.8%, 65J-47.3%. All diets provided nitrogen and energy in excess of maintenance requirements, as reflected by weight gains for all animals in every trial. Fecal and urinary nitrogen losses did not appear to be related to tannin content of the diets, since juvenile oak diets resulted in reduced nitrogen outputs, presumably due to reduced nitrogen intakes for these diets. We conclude that Gambel oak, even juvenile material in high dietary percentages (95%), provides adequate nutrients and should be considered a valuable forage for goats in oakbrush habitats.
    • Preferences of mule deer for 16 grasses found on Intermountain winter ranges

      Austin, D. D.; Stevens, R.; Jorgensen, K. R.; Urness, P. J. (Society for Range Management, 1994-07-01)
      In rangeland revegetation, selection of forages palatable to the primary grazer is crucial Five tame mule deer were used in the spring and fall to determine forage preferences for 16 grasses commonly found on seeded foothill rangelands. Trials were conducted within a planted enclosure. Cheatgrass (Bromus tectorum L.) was the most preferred species in spring, and also preferred in fall. Other preferred species included 'Paiute' orchardgrass (Dactylis glomerata L.), 'Luna' pubescent wheatgrass (Agropyron trichophorum link.), and fairway wheatgrass (Agropyron cristatum [L.] Gaertn). The least preferred grasses were three species of wildrye, 'Vinall' and 'Boisoisky' Russian wildrye (Psathyrostachys juncea Fisch.) and 'Magnar' basin wildrye (Elymus cinereus Scrib. and Merr.). Results showed a wide range of preferences for grasses.
    • Relationship of dietary browse to intake in captive muskoxen

      Boyd, C. S.; Collins, W. B.; Urness, P. J. (Society for Range Management, 1996-01-01)
      The effect of dietary browse (Salix bebbiana Sarg.) on intake and activity of muskoxen (Ovibos moschatus Zimmermann) pastured in south-central Alaska was compared to animals on grass pasture only. In previous work, intake increased in penned animals fed increasing browse: hay rations, which presumably allowed for increased weight gain and wool fiber (qiviut) growth. Eight mature steers were divided into 2 treatments: 8 hours daily ad libitum access to browse plus pasture grass (Bromus inermis Leyss., Poa pratensis L. mix) or pasture grass only. Animals were placed in adaptation enclosures 10 days before each trial. Bundles of browse were tied to perimeter fences. Trials were conducted 3 times during the 1992 growing season. For the trials, animals of like treatment were placed in each of four 0.33 ha trial enclosures for 8 hours, every other day, for 6 days (3 trial days). Activity budgets were calculated using scan sampling. Hand-harvested simulated bites were weighed to determine bite size, an bite rate was calculated using focal sampling techniques. Intake was calculated as a function of bite size, bite rate, and time spent foraging. Intake was greater (P = 0.064) for animals with access to browse. Digestive physiology of mukoxen may have favored higher intake of a mixed grass-browse diet over grass alone. Previous data suggest that elevated intake increases weight gain and qiviut growth.
    • Response of Curlleaf Mountain Mahogany to Pruning Treatments in Northern Utah

      Austin, D. D.; Urness, P. J. (Society for Range Management, 1980-07-01)
      Production of curlleaf mountain mahogany (Cercocarpus ledifolius) within browsing height of big game on winter ranges was increased 500-900% when 90-99% of the canopy was pruned from mature trees. However, since adventitious sprouting did not occur, numerous live twigs must be present in the browsing zone before treatment for any practical benefit to accrue. Pruning at less than 90% canopy removal and girdling showed positive but smaller vegetative responses, while 100% canopy removal and application of pruning paint to wound surfaces in an attempt to eliminate sap flow had no effect on forage production available to big game.
    • Small Mammal Abundance on Native and Improved Foothill Ranges, Utah

      Smith, C. B.; Urness, P. J. (Society for Range Management, 1984-07-01)
      Small mammal populations were sampled annually over 4 years in native plant communities and improved rangeland types. All species of rodents were relatively less abundant where western wheatgrass was the dominant vegetation, but other differences among types were specific to individual species. Due to species-specific habitat preferences, total rodent numbers were highest where both sagebrush and seeded vegetation occurred together, and total rodent biomass was slightly greater along this ecotone than in a pure sagebrush type. Small-scale type conversion projects designed to increase the diversity of seeded and native stands may maintain or increase rodent abundance where species with such dissimilar habitat requirements occur.
    • Some Factors Affecting Twig Growth in Blackbrush

      Provenza, F. D.; Malechek, J. C.; Urness, P. J.; Bowns, J. E. (Society for Range Management, 1983-07-01)
      Domestic goat browsing was used to stimulate twig production by blackbrush. Precipitation, soil depth and stoniness, branch location, and the number of years of browsing and rest from browsing affected twig production (P<0.05). As precipitation doubled, production increased by a factor of 1.9. Twig production by plants growing on deep soils (71 cm) was 1.9 times that by plants growing on shallow soils (39 cm). Older branches growing on the outer edges of blackbrush plants (terminal branches) produced 4.6 times more current season's twigs than sprouts and young branches (basal branches) growing within the shrub canopy. Heavily browsed plants increased twig production by a factor of 3.6 relative to control plants, and production remained at this level, even after 4 consecutive years of browsing. Annual twig production declined with rest from browsing. However, plants that were browsed and subsequently rested for 2 years yielded an aggregate 1.6 times more available forage than plants that were browsed on a yearly basis. This was due to an accumulation of twigs ranging in age from 1 to 3 years.
    • Spring Livestock Grazing Affects Crested Wheatgrass Regrowth and Winter Use by Mule Deer

      Austin, D. D.; Urness, P. J.; Fierro, L. C. (Society for Range Management, 1983-09-01)
      Areas grazed and ungrazed by cattle in spring were compared for regrowth of crested wheatgrass on a big sagebrush-grass range. Overwinter utilization of crested wheatgrass by tame mule deer and their grazing area preferences were assessed under 3 snow cover conditions-snow free, partial, and complete. Results showed regrowth production was usually higher on areas previously ungrazed by livestock. Overwinter utilization of created wheatgrass by deer was determined to be greater on ungrazed areas in both percentage of available grass used and weight per unit area consumed. Thus, interference from cured growth limiting green grass availability was more than compensated by increased production. The percentage of grass in the diet was generally higher on areas ungrazed by cattle, and deer preferred these areas under snow free and partial snow cover conditions; no preference was exhibited during complete snow cover. Recommendations for livestock grazing of seeded, foothill ranges where deer use is critical are discussed.
    • Technical Note: A total urine collection apparatus for female bison and cattle

      Deliberto, T. J.; Urness, P. J. (Society for Range Management, 1995-01-01)
      A urinary collection device is described for use in metabolism studies on female bison (Bison bison) and cattle. Separating urine from feces, and collecting all urine produced by female animals in metabolism stalls present difficulties. Catheters are usually used on animals in confinement, but often with varying degrees of success. Thus, an external device designed to divert urine into collection receptacles was developed. The urine collection apparatus was used successfully in six 8-day metabolism trials conducted during 1991 and 1992.