bluuebunny/crossref_metadata_2025 huggingface dataset:
Animal age and sex effects on diets of grazing cattle
Authors: Grings E. E. , Short R. E. , Haferkamp M. R. ,   Society for Range Management
Published: March 2016

The effects of animal age and sex on chemical and botanical composition of diets of cattle grazing native rangelands were evaluated in a 2-year study. Samples were collected monthly from June through October using esophageally cannulated suckling calves, yearling heifers, mature cows, and mature steers. Dietary crude protein and digestibility differed among animal classes, but these differences varied over time. These 2 diet quality indicators did not vary in the same manner over time for all animal classes. Dietary crude protein varied from a low of 7.2% for steers in August 1994 to a high of 14.3% for heifers in June 1993. In vitro digestibility varied from a low of 50.7% for cows in October 1993 to a high of 74.3% for calves in June 1993. Botanical composition of diets varied with animal class and sampling date with interactions among these. Cool-season grasses accounted for an average of 70% of the diet with a range of 33 to 90%. Shrubs varied from 1 to 61% of the diet. Differences in chemical composition among age and sex classes of cattle grazing native rangeland during the growing season may be partially related to differences in botanical composition of diets. Animals used to obtain diet samples should, therefore, be of similar physiological state and age as animals being monitored for performance.
Coyote responses to changing jackrabbit abundance affect sheep predation
Authors: Stoddart L. C. , Griffiths R. E. , Knowlton F. F. ,   Society for Range Management
Published: March 2016

Domestic sheep ranchers generally perceive abundances of natural prey and coyotes (Canis latrans) as important factors affecting coyote predation rates on sheep. To determine the effect of a changing natural prey base on coyote predation rates, we estimated coyote density and predation rates on ewes and lambs during part of 1 cycle of black-tailed jackrabbit (Lepus californicus) abundance on a 2,300 km2 area of the Idaho National Engineering Laboratory in southcentral Idaho from 1979-1985. We used 100, 1.6-km scat collection lines and 80, 1.6-km flushing transects to assess coyote and jackrabbit densities, respectively. Ewe and lamb loss rates were determined from questionnaires sent to all 13 producers grazing sheep on the area. Spring coyote density varied from 0.10 to 1.39 coyotes km-2 in response to a systematic fluctuation in jackrabbit density from 0 to 243 jackrabbits km-2. Reported total loss rates of ewes and lambs varied from 2.2 to 42.1 ewes/10(5) ewe-days and 33.0 to 163 lambs/10(5) lamb-days and were linearly and directly related to coyote density (P < 0.005). Ewe and lamb loss rates were independent of jackrabbit density (P > 0.18) except for 1 year when jackrabbits were virtually absent from the study area and the loss of lambs escalated dramatically. Our data suggest the increased losses of lambs resulted from reduced buffering by natural prey.
Estimating herbage standing crop with visual obstruction in tallgrass prairie
Authors: Vermeire L. T. , Gillen R. L. ,   Society for Range Management
Published: March 2016

We evaluated the visual obstruction method as a non-destructive means of estimating herbage standing crop in tallgrass prairie. Prediction models were developed for both plot-level and pasture-level estimates by regressing standing crop from clipped plots on visual obstruction measurements (VOM) from 48, 20-sample trials. Trials were conducted year-round on burned and non-burned sites in different seral stages and with various levels of productivity and grazing pressure. Separate models were required for burned and non-burned pastures, but both applied across all other variables and were unaffected by community heterogeneity. Coefficients of determination were 0.95 and 0.90 for burned and non-burned pastures, respectively. Use of a more precise measurement scale for visual obstruction did not improve the prediction models. Models for standing crop based on individual quadrats explained less variation than models based on transect averages. The highest correlations with visual obstruction were obtained with 20 x 50 cm quadrats placed adjacent to the measurement pole and oriented toward the observer. The visual obstruction method required little training and mean deviations of student readings from those of the trainer were less than 1 cm. Sampling efficiency is improved with the visual obstruction method because it is reasonably accurate and 6 times faster than clipping. Standing crop estimates can be calculated immediately and less field equipment is needed.
Observation: Long-term increases in mesquite canopy cover in a north Texas savanna
Authors: Ansley R. J. , Wu X. B. , Kramp B. A. ,   Society for Range Management
Published: March 2016

It is necessary to quantify rates of woody plant encroachment on southwestern USA rangelands to determine the economic feasibility of treatments designed to manage these plants. This study observed changes in honey mesquite (Prosopis glandulosa Torr.) canopy cover over a 20-year period (1976-1995) in 2 treatments: an untreated area that initially had a moderately dense mesquite stand (14.6% cover), and an area cleared of mesquite with root-plowing in 1974. Canopy cover of mesquite was estimated from scanned color-infrared aerial photograph images by manually delineating mesquite canopies with a computer using ArcView software. During the 20 years, mesquite cover in the untreated area increased (P less than or equal to 0.05) from 14.6 to 58.7%, averaging 2.2 percentage units per year. Cover in the root-plow treatment also significantly increased during the same period from 0 to 21.9% (1.1 percentage units per year), but the rate of increase was significantly lower than in the untreated area because mesquite growth was from new seedlings instead of established plants and/or new seedlings as occurred in the untreated area. Rate of increase was significantly lower from 1976 to 1990 (1.6 and 0.2 percentage units per year) than from 1990 to 1995 (4.1 and 3.7 percentage units per year) in the untreated and root-plow treatment, respectively. These differences were attributed to precipitation which was near normal from 1976 to 1990 but 25% above normal from 1991 to 1995.
Journal of Range Management, Volume 54, Number 2 (March 2001)
Authors:   Society for Range Management
Published: March 2016

Complete digitized issue.
Technical Note: A simple method for preparing reference slides of seed
Authors: Dacar M. A. , Giannoni S. M. ,   Society for Range Management
Published: March 2016

Microhistological analysis has become the most commonly used and successful method for determining micromammal diets. However, this technique has a number of limitations, particularly when used on fecal samples where identification of some items is difficult. This method underestimates those nearly unrecognizable plant parts in the diet, such as seed, and overestimates easily identifiable parts, such as leaf epidermis. In this note we describe a simple technique that uses a macerating solution of 17.5% NaHCO3 for preparing reference slides of seeds. Advantages of the proposed method are discussed and compared with Jeffrey's technique.
Technical Note: Early harvest of squirreltail seed
Authors: Doescher P. S. ,   Society for Range Management
Published: March 2016

Squirreltail (Sitanion hystrix (Nutt. J. G. Smith), a native, cool-season perennial bunchgrass of the Intermountain West has been shown to reinvade degraded rangelands invaded by exotic annual weeds. However, one limitation to mechanical seed collection of this species is the disarticulating nature of the rachis at seed maturity. The purpose of this research was to determine if early harvest of the inflorescence before disarticulation would result in viable seed. After anthesis, seeds were collected weekly in 1995 and about every 10 days in 1996 at a research site near Prineville, Oregon. Seeds were germinated for 21 days at a constant temperature of 20 degrees C. Germinable seeds were present at all collection dates from late anthesis to seed shatter in 1995, and all but early anthesis in 1996. Total germination, rate of germination and seed weight increased as seeds were collected later in the summer. Collection of squirreltail seed when a majority of seed awns have moved from a reddish to a divergent, straw colored appearance resulted in germination properties similar to fully mature seed. This occured about 1 week prior to the onset of seed head disarticulation.
Demographic characteristics of 3 Artemisia tridentata Nutt. subspecies
Authors: Perryman B. L. , Maier A. M. , Hild A. L. ,   Society for Range Management
Published: March 2016

Previous research suggested that woody plant recruitment may occur in pulses in semi-arid areas. The overall objective of this study was to determine if this pulse phenomena was recorded in the demographic structures of big sagebrush (Artemisia tridentata Nutt.) stands in Wyoming. In 1997, approximately 75 stem cross sections were collected from 9 stands of each of 3 subspecies of big sagebrush in Wyoming along elevation and climatic gradients. Annual growth-rings were used to identify year of establishment and demographic characteristics were analyzed from age-class frequencies. Mean stand ages of the 3 subspecies were different (P = 0.002), and analyses revealed that Wyoming (A. tridentata ssp. wyomingensis) and mountain big sagebrush (A. tridentata ssp. vaseyana) stand ages (32 +/- 9 and 26 +/- 9 years, respectively) were significantly older than basin big sagebrush (A. tridentata ssp. tridentata) (17 +/- 3) stands (P < 0.05). Mean recruitment intervals (years) were shorter for basin (1.6) than for Wyoming (2.3) and mountain (2.2) sagebrush (P = < 0.01). The number of cohorts did not differ among the subspecies (P = 0.11), but the percent of years with recruitment was significantly higher for basin (59%) compared to Wyoming (37%) and mountain (39%) subspecies (P 0.0001). Age-class frequency distributions of each stand and regional stand combination were assessed for dispersion across each associated period of record. Chi-square goodness-of-fit tests were performed for the negative binomial distribution. All stands (with one exception) and all 3 regional stand combinations fit the negative binomial distribution. Age-class frequency patterns indicate that recruitment is clustered or aggregated across each period of record. Recruitment in big sagebrush stands occurs in pulses throughout Wyoming.
Cover for wildlife after summer grazing on Sandhills rangeland
Authors: Reece P. E. , Volesky J. D. , Schacht W. H. ,   Society for Range Management
Published: March 2016

Livestock production and wildlife habitat objectives become antagonistic on grasslands when the architecture of standing herbage needed for key wildlife species limits the amount of forage that can be used by livestock. However, quantitative information needed to achieve cover objectives for wildlife is not available for summer-grazed grasslands. Three replicates of 7 grazing treatments were applied to the same 1.0-ha pastures for 3 years. Treatments included ungrazed control, and grazing at 16, 32, or 48 animal unit days (AUD) ha(-1) for 5 to 7 days during mid-June or mid-July. Cover was estimated after killing frost in September by measuring the average height below which complete visual obstruction occurred. Cumulative grazing pressure (AUD Mg(-1)) was used to describe grazing effects because of measurable differences in herbage among pastures and dates. Grazing in June reduced the average height of autumn cover at a constant rate from 11.0 to 7.0 cm (R2 = 0.34) as cumulative grazing pressure increased from 16 to 90 AUD Mg(-1). In contrast, declines in cover after grazing in July were about 2.6 times greater for cumulative grazing pressures up to 40 AUD Mg(-1) (R2 = 0.62), indicating a measurable decline in plant growth and an increasing dependence of autumn cover on the remaining herbage when grazing ended. Relatively low predictability of autumn cover after June compared to July grazing was offset by more plant growth during the balance of the growing season. Frequency of low-cover patches (less than or equal to 5.0 cm) within pastures was highly correlated (R2 = 0.94) with mean estimates of autumn cover. Consequently, the quality of cover near potential nesting sites also declined as the average height of cover declined, regardless of grazing date. The interdependence of low-cover patches and mean visual obstruction indicates that either variable could be the primary criterion for nest site selection up to 12 cm in visual obstruction.
Supplemental polyethylene glycol influences preferences of goats browsing blackbrush
Authors: Titus C. H. , Provenza F. D. , Perevolotsky A. ,   Society for Range Management
Published: March 2016

Supplemental polyethylene glycol (PEG) increases intake of foods high in tannins, but it is not known if PEG affects preference when herbivores forage on a variety of foods that differ in concentrations of macronutrients and tannins. We investigated how macronutrients, tannins, and PEG affected preferences of goats (Caprus hircus) for current season's and older growth twigs from the shrub blackbrush (Coleogyne ramosissima Torr.). In blackbrush, current season's twigs are higher than older twigs in macronutrients, but goats prefer older twigs because high levels of tannins in current season's twigs decrease preference. We conducted a pen trial and a paddock trial. During the 7-day pen trial, goats were offered current season's twigs and older twigs throughout the day. Eight goats were supplemented with 20 g PEG mixed with 100 g ground alfalfa (Medicago sativa L.) pellets, and 8 goats were supplemented with 100 g ground alfalfa pellets. Goats supplemented with PEG ate more current season's twigs than goats that did not receive PEG (P = 0.04). During the 17-day paddock trial, 10 goats were supplemented with 50 g PEG mixed with ground alfalfa/barley (Hordeum vulgare L.), and 10 goats were supplemented with ground alfalfa/barley. Goats supplemented with PEG preferred current season's to older twigs, whereas PEG-unsupplemented goats preferred older to current season's twigs (P = 0.0001). Goats had equal preference for juniper (Juniperus osteosperma Torr.) trees (P = 0.243). Collectively, our findings show that supplemental PEG can change food preferences.
Chain diker effects on seeded grass establishment following disk chaining
Authors: Wiedemann H. T. , Cross B. T. ,   Society for Range Management
Published: March 2016

Placing basins in rangeland seedbeds to capture rainfall has enhanced seeded grass establishment, but it has not been practical on debris-littered land following rootplowing for brush control. A disk chain tested previously will traverse land littered with debris or shrubs while tilling the soil for seedbed preparation. A chain diker is an implement designed to form 10-cm deep basins with a volume of 3.9 +/- 0.9 liters on tilled land. Combining the 2 implements provided tillage, land smoothing and basin formation in the soil with a single pass on debris littered land. Our 4-year study compared established grass densities on disk-chained seedbeds with and without chain diking at 5 locations in west Texas where land was rootplowed for honey mesquite (Prosopis glandulosa Torr. var. glandulosa) control. At 4 locations seedbeds were aerially seeded with 2 kg ha(-1) pure live seed (PLS) of WW Spar bluestem (Bothriochloa ischaemum (L.) Keng). At 1 location a mixture of 6 grasses, including Spar bluestem, was aerially seeded at 2.8 kg ha(-1) PLS. Evaluations were based on established grass densities at the end of the first growing season. At 3 locations, a seeding-before-diking treatment was included to simulate seed dropping from a seedbox mounted over the disk-chain's roller. In the Rolling Plains region of northwest Texas (4 sites), when growing-season rainfall was less than 400 mm, chain-diked seedbeds increased grass densities 2.6 times (P = 0.05) compared to non-diked seedbeds. When growing-season rainfall was greater than 500 mm, grass densities on diked seedbeds were similar to non-diked seedbeds. In the Trans-Pecos region of far-west Texas (1 site), where average growing-season rainfall is 337 mm, diked seedbeds produced 33% greater grass densities (P = 0.05) than non-diked seedbeds with rainfall of 552 mm. Densities of kleingrass (Panicum coloratum L.) and Spar bluestem were significantly greater in the diked seedbeds compared to non-diked seedbeds, and the other 4 grasses were not significantly influenced by seedbed methods. Grass densities were similar whether seeding after diking or before diking. Since long-term, growing-season rainfall has averaged below 500 mm between 65% to 87% of the time at these locations, our data suggests that it would be advantageous to include chain diking in combination with disk chaining for grass establishment on rootplowed land littered with brush debris.
Journal of Range Management, Volume 54, Number 3 (May 2001)
Authors:   Society for Range Management
Published: March 2016

Complete digitized issue.
Herbage response to precipitation in central Alberta boreal grasslands
Authors: Bork E. W. , Thomas T. , McDougall B. ,   Society for Range Management
Published: March 2016

The dependence between grassland herbage production and precipitation within the Boreal region of central Alberta was evaluated. Additional objectives were to compare current year growing season (e.g., April or May, to August) precipitation with 12 and 16 month water year (e.g., dormant and growing season) precipitation for use in predicting herbage growth, and determine whether lowland and upland grasslands differ in their response to precipitation. Lowland herbage production averaged 6,053 kg ha(-1), nearly twice the 3,153 kg ha(-1) found on upland grasslands during the study. In general, herbage production correlated significantly with precipitation, but the magnitude and direction of that relationship varied depending on grassland type. Uplands displayed a positive linear relationship with precipitation (r = 0.76; p < 0.01), while lowland communities displayed a negative curvilinear (R2 = 0.65; p < 0.05) relationship. Furthermore, while herbage production on uplands was better predicted by current year precipitation, lowland production appeared more heavily dependent on precipitation falling during the water year, the latter of which included fall and winter moisture recharge. We hypothesize that these differences are linked to water redistribution within the landscape, along with subsequent soil temperature regimes and the length of effective growing season. Given the influence of topography in regulating water availability and use, rangeland managers within the Boreal region should use caution when determining rangeland carrying capacity from meteorological data.
Antelope bitterbrush seed production and stand age
Authors: Clements C. D. , Young J. A. ,   Society for Range Management
Published: March 2016

Antelope bitterbrush (Purshia tridentata (Pursh) DC) is the most important browse species on many western mule deer (Odocoileus hemionus) ranges. Lack of antelope bitterbrush seedling recruitment is a critical problem, and therefore, the influence of livestock grazing on antelope bitterbrush seed production is an important issue. Seed production was compared in grazed and ungrazed communities during 1995 and 1996 at 2 locations in northeastern California and one location in northwestern Nevada. A system of seed traps was used to estimate seed production in relation to the size, age and grazing of antelope bitterbrush plants in the various stands. Antelope bitterbrush seed production was significantly (P less than or equal to 0.01) higher at one of the ungrazed sites. Significant (P less than or equal to 0.05) differences in shrub ages were also recorded between sites.
Canadian bluejoint response to heavy grazing
Authors: Collins W. B. , Becker E. F. , Collins A. B. ,   Society for Range Management
Published: March 2016

A disclimax stand of Canadian bluejoint (Calamagrostis canadensis (Michx.) Beauv.) was heavily grazed by cattle and horses for 4 years to weaken the grass's competition with hardwoods important as browse and cover to wildlife. Stocking at 0.084 ha AUM(-1) resulted in uniform utilization of bluejoint and maintenance of early phenology through the growing season. Etiolated bluejoint declined about 90%, but grass production increased 10 to 15%, as fireweed (Epilobium angustifolium L.), a principal herbaceous component of the stand, decreased in response to trampling. Rhizomes of heavily grazed bluejoint had lower total nonstructural carbohydrates (TNC) (p = 0.0127), lower weight (g cm(-1) length) (p = 0.05), and reduced biomass (g cm(-3) of soil) (p = 0.05). Shoots of grazed bluejoint maintained higher nitrogen (p = 0.0001) and higher digestibility (IVDMD) (p = 0.0017) than bluejoint that was never grazed. This enabled heavily grazed bluejoint to retain good forage quality through the entire growing season, as opposed to ungrazed bluejoint, which became poor forage at the time of flowering during early July. Following one season of rest, rhizome TNC, shoot nitrogen, and IVDMD returned to levels of never grazed bluejoint. Seedhead production, seed production, seed weights, and seed viability of rested bluejoint were about the same as in ungrazed stands. On wet sites, heavy grazing does not adequately reduce the vigor of this grass.
Remote sensing of redberry juniper in the Texas rolling plains
Authors: Everitt J. H. , Yang C. , Racher B. J. ,   Society for Range Management
Published: March 2016

Redberry juniper (Juniperus pinchotii Sudw.) is a noxious shrub or small tree that invades rangelands in northwest Texas. Field reflectance measurements showed that redberry juniper had lower visible and higher near-infrared (NIR) reflectance than associated species and mixtures of species in February. The low visible reflectance of redberry juniper was due to its darker green foliage than associated species, whereas its high NIR reflectance was attributed to its greater vegetative density than associated vegetation. Redberry juniper had a distinct reddish-brown image tonal response on color-infrared aerial photographs obtained in February. Computer analysis of a color-infrared photographic transparency showed that redberry juniper infestations could be quantified. An accuracy assessment performed on the classified image had a user's accuracy of 100% and a producer's accuracy of 94% for redberry juniper.
Forage kochia seed germination response to storage time and temperature
Authors: Kitchen S. G. , Monsen S. B. ,   Society for Range Management
Published: March 2016

The Eurasian low-shrub, forage kochia [Kochia prostrata (L.) Shad.], was introduced into western North America for use in restoration of severely disturbed landscapes in arid and semiarid environments. Seed mature in late fall and are short-lived in typical warehouse conditions. In a preliminary, cold-temperature experiment (2 degrees C) using 3-month-old seed from 16 forage kochia accessions, mean germination time, expressed as days to 50% germination, varied from 4 to 88 days. Follow up experiments using seed of 5 accessions tested the effects of storage time and temperature on seed viability and mean germination time and related this to field planting success. Sub-samples were air-dried and stored in plastic bags in a freezer, cold room, and lab (-15, 2, and 20 degrees C respectively). A fourth set of subsamples was stored in a shed with no temperature control (simulated warehouse storage). Seed were tested fresh and retested after 4, 8, 12, 24, and 36 months of storage. Mean viability decreased from 77% (range 66 to 93%) for recently harvested seed, to 24 and 8% for lab- and shed-stored seed, after 36 months of storage. No significant change in viability was observed for cold room- and freezer-stored seed. Across all accessions, cold temperature mean germination time (MGT) for recently harvested seed was 73 days (range 51 to 109 days). For each accession, germination occurred primarily over a 70 day period. Mean germination time decreased as storage time increased for lab- and shed-stored seed, varied unpredictably for cold room-stored seed, and remained unchanged for freezer-stored seed. Field germination using 1- and 2-year old lab- and shed-stored seed was significantly faster than that of same-aged cold room- and freezer-stored seed. The number of live seedlings 4 months after planting for cold room- and freezer-stored seed was 10-fold or greater than that of lab- and shed-stored seed. Thus a delayed, asynchronous cold-temperature germination pattern appears to be adaptive for forage kochia establishment. Cold, dry storage prevents loss of seed viability and preserves this desirable germination pattern.
Restoring degraded riparian meadows: Biomass and species responses
Authors: Martin D. W. , Chambers J. C. ,   Society for Range Management
Published: March 2016

Riparian meadows in central Nevada are highly productive and have been extensively utilized for livestock grazing. Consequently, many have been severely degraded resulting in changes in species composition and decreases in productivity. During a 3 year study, we examined the responses of mesic meadow systems to yearly nitrogen addition (100 kg ha(-1)) and clipping (8-10 cm stubble height) to increase our understanding of grazing effects. We also examined the effects of a one-time, fall aeration (10 cm deep by 2 cm wide holes spaced 20 cm apart) and revegetation (removal of existing vegetation and reseeding) to evaluate the restoration potential of these sites. Changes in total biomass, species aerial cover and frequency, and surface basal cover were used to evaluate treatment responses. Clipping had no effect on total biomass, possibly because it was conducted late in the growing season. In contrast, nitrogen addition plus clipping increased biomass in all 3 years when treatments were compared across sites and for 1 out of 3 years when treatments were compared across a single site. Aeration had no effect on above ground biomass, but has been shown to increase rooting activity in these same meadows. Due to a dry, hot spring, early seral and weedy species had higher establishment than the seeded natives in the revegetation plots, and biomass was low the first year after treatment. Individual species varied in their treatment responses. The cover of low-growing forb species (western aster (Aster occidentalis [Nutt.] Torrey and A. Gray), long-stalk starwort (Stellania Longipes Goldie), and common dandelion (Taraxacum officinale Wigg.) declined through time for all treatments, presumably due to increased grass cover and shading following release from grazing and above average precipitation and water table levels in 1998. Examination of the key graminoids showed that Kentucky bluegrass (Poa pratensis ssp. pratensis L.), an increaser species, did not increase in response to release from grazing, but increased in response to clipping and nitrogen addition. Nebraska sedge (Carex nebrascensis Dewey), a desirable native, increased in response to both release from grazing and nitrogen addition. The results were influenced by high spatial and temporal variability in water table elevations within these systems.
Activity budgets and foraging behavior of bison on seeded pastures
Authors: Rutley B. D. , Hudson R. J. ,   Society for Range Management
Published: March 2016

Activity budgets and foraging behavior of yearling bison (Bison bison L.) on pasture were studied during quarterly trials between June 1994 and December 1995. Daily activity patterns were polyphasic with alternating bouts of foraging and resting activity. During winter, bison displayed 2 main daytime foraging bouts and significant nighttime foraging. During summer, phasic activity was poorly expressed due to the increased number of cycles. Total foraging time declined from summer to winter (763 +/- 62 to 470 +/- 32 min day(-1)) while bedding bout length increased (121 +/- 13 to 276 +/- 26 min day(-1)). Bison selected forage higher in crude protein (12.9 +/- 0.8 vs 10.0 +/- 0.8%), higher in predicted digestible energy (2.70 +/- 0.09 vs 2.17 +/- 0.09 Mcal kg(-1)), lower in acid detergent fiber (31.9 +/- 0.9 vs 38.8 +/- 0.9%), and lower in lignin (4.8 +/- 0.3 vs 6.8 +/- 0.3%, respectively) than forage available within grazed patches.
Anti-quality components in forage: Overview, significance, and economic impact
Authors: Allen V. G. , Segarra E. ,   Society for Range Management
Published: March 2016

Although recognized in importance from the dawn of history, forages have too often been underestimated and undervalued perhaps in part because animal performance has frequently failed to reflect apparent forage quality. Anti-quality components, diverse impediments to quality, have evolved as structural components and as secondary metabolites. They include mineral imbalances or can be related to the presence of insects and diseases. Animal behavior and adaptation are increasingly recognized as important aspects of anti-quality factors. An anti-quality component may reduce dry matter intake, dry matter digestibility, or result in nutritional imbalances in animals. They can act as a direct poison compromising vital systems, result in abnormal reproduction, endocrine function, and genetic aberrations, trigger undesirable behavior responses, or suppress immune function leading to increased morbidity and mortality. The economic impact of anti-quality factors on individual herds can be devastating but definable. Broadscale economic impacts of anti-quality factors are far more difficult to estimate. A loss of 0.22 kg/day in potential gain of stocker cattle due to anti-quality factors during a 166-day grazing season translates into a loss of about 55/steer at 1.45/kg or over 2 billion annually when applied to the U.S stocker cattle. Economic losses to tall fescue (Festuca arundinacea Schreb.) toxicosis in the U.S. beef industry are probably underestimated at 600 million annually. Reproductive and death losses of livestock due to poisonous plants have been estimated at 340 million in the 17 western states alone. These examples of economic losses due to anti-quality factors may be upper bounds of actual losses but even if a small proportion of the expected losses were eliminated through research, the potential payoff would be extremely high.
Cattle use of foothills rangeland near dehydrated molasses supplement
Authors: Bailey D. W. , Welling G. R. , Miller E. T. ,   Society for Range Management
Published: March 2016

Strategic supplement placement has been shown to be an effective tool to lure cattle to underutilized rangeland. The goal of this study was to determine where cattle grazed when supplement was placed in foothills rangeland. The study was conducted in 4 pastures in northern Montana that were dominated by cool-season grasses. For 2-week periods beginning in October 1998 and ending in January 1999, dehydrated molasses blocks (30% CP) were placed in locations within 3 pastures that were steeper and further from water. Forage utilization was measured at the time of supplement placement and again at removal. Increases in forage utilization during each period (14%) were similar (P > 0.1) at distances of 30 to 600 m from supplement, and increases were additive across periods. Forage utilization was evaluated in a fourth pasture during August and September 1999 at distances of 50 to 3,000 m from the supplement. Forage use declined (P < 0.01) at further distances from supplement, and forage use at distances less than 600 to 800 m from supplement was greater than the average of all measurements collected throughout the pasture. During the autumn and early winter at the 2 pastures located near Havre, Mont., 53% of the cows were observed within 600 m of supplement and 47% were observed at greater distances from supplement. Eighty-one of the 159 cows grazing the 2 pastures near Havre (245 and 330 ha) were fitted with Global Positioning System (GPS) tracking collars. The collared cows spent 37% of their time within 600 m of supplement. Uniformity of cattle grazing can be enhanced by the placement of dehydrated molasses supplement in rugged topography, and the area influenced can include distances up to 600 m from supplement.
Journal of Range Management, Volume 54, Number 4 (July 2001)
Authors:   Society for Range Management
Published: March 2016

Complete digitized issue.
Anti-quality effects of insects feeding on rangeland plants: A review
Authors: Campbell J. B. ,   Society for Range Management
Published: March 2016

The anti-quality effects of the major groups of insects that utilize rangeland plants for food is discussed. The biology, ecology, geographical distribution and economic thresholds of grasshoppers, crickets, Western harvester ants, ranch caterpillars, big-eyed or black grass bugs, and white grubs are reviewed. Also discussed are practical pest management strategies if they exist. Most of these rely on the integration of good range management practices and the control strategy.
Practical measures for reducing risk of alfalfa bloat in cattle
Authors: Majak W. , Hall J. W. , McAllister T. A. ,   Society for Range Management
Published: March 2016

Frothy bloat in cattle is a serious problem and is difficult to manage under field conditions as it progresses rapidly from early signs of distension to acute distress. Scientists at Agriculture and Agri-Food Canada centres in Western Canada are committed to the development of bloat-free alfalfa grazing systems, which may require feed additives or supplements. As well, a new cultivar of alfalfa (AC Grazeland), selected for a low initial rate of digestion, will soon be available. In grazing trials the cultivar reduced the incidence of bloat by an average of 56% compared with the control cultivar (Beaver). Commonly accepted mineral mixes for the prevention of bloat were tested and found ineffective but we have confirmed that poloxalene (Bloatguard®) is 100% effective if it is given intraruminally at the prescribed dose. However, under practical conditions, poloxalene can only be offered free choice and protection from bloat cannot be guaranteed. We have also shown that the water soluble polymer, Blocare® 4511, when used in the water supply is 100% effective in bloat prevention. This product is not yet registered in North America. Other strategies for bloat prevention will be discussed, including the selection of growth stages and grazing schedules, and the reduction of risk by wilting alfalfa or combining it with tannin-containing forages.
Review of toxic glycosides in rangeland and pasture forages
Authors: Majak W. ,   Society for Range Management
Published: March 2016

Ruminants are a diverse group of mammals, both domestic and wild species, that exhibit microbial fermentation prior to gastrointestinal activity. During the digestive process, glycosides and other natural products are exposed to ruminal microorganisms and metabolised as substrates. Most compounds are converted into nutrients but some become toxic metabolites. At least 10 types of toxic glycosides occur in forage species. Glycosides are characterized by the presence of one or more sugars linked to the alcohol or thiol functions of the non-sugar portion of the molecule, which is called the aglycone. The biological activity of the glycoside is usually determined by the chemical nature of the aglycone. The aglycones are released by microbial enzymes and may undergo further enzymatic or non-enzymatic transformations to yield toxic metabolites that can be absorbed from the gastrointestinal tract. Microbial detoxification of the aglycone is also possible. Further biotransformation of the aglycone can occur in the liver. A review is presented on glycosides that are toxic to ruminants. The discussion covers aliphatic nitrocompounds, cyanogenic glycosides, cardiac glycosides, saponins, glucosinolates, diterpenoid glycosides, bracken glycosides, calcinogens, phenolic glycosides and ranunculin. Clinical signs of poisoning and treatment of livestock as well as management strategies for the prevention of poisoning are considered.
Restoring tallgrass prairie species mixtures on leafy spurge-infested rangeland
Authors: Masters R. A. , Beran D. D. , Gaussoin R. E. ,   Society for Range Management
Published: March 2016

Leafy spurge (Euphorbia esula L.) reduces northern Great Plains rangeland carrying capacity. Treatment strategies were evaluated that suppressed leafy spurge and facilitated establishment of mixtures of native grasses and legumes on range sites near Mason City and Tilden, Nebr. Glyphosate at 1,600 g a.i. (active ingredient) ha(-1) was applied with or without imazapic at 140 or 210 g a.i. ha(-1) in October 1995. In April 1996, standing crop was burned or mowed. Mixtures of native grasses [big bluestem (Andropogon gerardii Vitman), indiangrass (Sorghastrum nutans (L.) Nash), switchgrass (Panicum virgatum L.), little bluestem (Schizachyrium scoparium (Michx.) Nash), and sideoats grama (Bouteloua curtiplendula (Michx.) Torr.)] were then planted with or without native legumes [leadplant (Amorpha canescens (Nutt.) Pursh), Illinois bundleflower (Desmanthus illinoensis (Michx.) MacM.), and purple prairieclover (Petalostemum purpureum (Vent.) Rybd.)] at 440 pls m(-2) into a non-tilled seedbed. Imazapic was applied at 70 g a.i. ha(-1) in June 1996 to half the plots that had been treated with imazapic in October 1995. Frequency, dry matter yield, and leafy spurge density were measured 14 to 16 months after planting. Leafy spurge density and yield were least, and frequencies and yields of the planted grasses usually were greatest where imazapic had been applied with glyphosate in October 1995. Purple prairieclover was the only planted legume to persist 14 months after planting, and yields were greatest where imazapic was applied with glyphosate. Imazapic applied in June 1996 usually did not improve planted species yields or leafy spurge control. Total vegetation yields were greater where imazapic was applied with glyphosate at both sites and where native species were seeded at Mason City. Vegetation suppression with fall-applied herbicides and removal of standing crop enabled successful establishment of desirable species, increased forage yields, and suppressed leafy spurge.
Animal health problems caused by silicon and other mineral imbalances
Authors: Mayland H. F. , Shewmaker G. E. ,   Society for Range Management
Published: March 2016

Plant growth depends upon C, H, O, and at least 13 mineral elements. Six of these (N, K, Ca, Mg, P, and S) macro-elements normally occur in plants at concentrations greater than 1,000 mg kg(-1) level. The remaining micro-elements (B, Cl, Cu, Fe, Mn, Mo, and Zn) normally occur in plants at concentrations less than 50 mg kg(-1). Trace amounts of other elements (e.g., Co, Na, Ni, and Si) may be beneficial for plants. Silicon concentrations may range upwards to 50,000 mg kg(-1) in some forage grasses. Mineral elements required by animals include the macro-elements Ca, Cl, K, Mg, N, Na, P, and S; the trace or micro-elements Co, Cu, Fe, I, Mn, Mo, Se, and Zn; and the ultra-trace elements Cr, Li, and Ni. When concentrations of these elements in forages get 'out of whack' their bioavailability to animals may be jeopardized. Interactions of K x Mg x Ca, Ca x P, Se x S, and Cu x Mo x S are briefly mentioned here because more detail will be found in the literature. Limited published information is available on Si, so we have provided more detail. Silicon provides physical support to plants and may reduce susceptibility to pests. However, Si may have negative effects on digestibility and contribute to urinary calculi in animals.
Carbon and nitrogen dynamics in elk winter ranges
Authors: Menezes R. S. C. , Elliott E. T. , Valentine D. W. ,   Society for Range Management
Published: March 2016

Recent increases in elk (Cervus elaphus L.) herbivory and changes in hydrology towards drier conditions have contributed to declines in willow (Salix spp. L.) communities in the winter ranges for elk in Rocky Mountain National Park. In 1994, we constructed 12 large elk exclosures in 2 watersheds of the winter range for elk in the park, and conducted field experiments from 1995 to 1999 to investigate the effects of herbivory and proximity to surface water on the dynamics of C and N. Litterfall biomass averaged 65.6 and 33.0 g m(-2) inside and outside the exclosures, respectively. Elk herbivory increased (P < 0.05) N concentration of willow litter from 1.25 to 1.49%, but there were no differences in losses of C and N from litterbags placed in grazed and ungrazed plots in any of the growing seasons. Carbon losses from litterbags were higher in lower landscape positions (P = 0.001), in comparison to upper landscape positions. Shoot biomass of willow plants fertilized with N averaged 27.3 g and was higher (P < 0.05) than that of unfertilized plants, which averaged 20.2 g, indicating that N availability limits plant growth in our study sites. Elk herbivory had no effect on soil inorganic N availability, even though we estimated that the return of N to the soil in grazed plots could be as much as 265% of the N return in exclosed plots. In the long-term, greater return of N to the soil combined with increased litter quality in the grazed plots could contribute to increases in N cycling rates and availability, and these changes could affect ecosystem structure and function in the winter range for elk in Rocky Mountain National Park.
Statistical analyses of fluorometry data from chloroform filtrate of lamb feces
Authors: Mukherjee A. , Anderson D. M. , Daniel D. L. ,   Society for Range Management
Published: March 2016

Accurately identifying the botanical composition of free-ranging animal diets remains a challenge. Currently accepted procedures are time consuming, many requiring painstaking sample preparation while none produce data useful for real-time management. Automated procedures focusing on detection of chemical and/or physical plant properties using specific molecules called fluorophores offers possibilities for determining the species composition of herbivore diets. This study was designed to evaluate fluorometry techniques in herbivore diet determinations using fecal samples obtained from 13 lambs fed a basal diet of tobosa hay (Pleuraphis mutica Buckley), and containing 4 different levels (0, 10, 20, and 30%) of tarbush (Flourensia cernua D C.) leaf material. Chloroform (CHCl3) filtrate obtained from the lamb's feces was exposed to UV light from a xenon arc lamp. This caused fluorophore molecules in the filtrate to have their outer shell electrons move to a higher energy state as a result of UV light excitation. After excitation by UV light at 310, 320, 330, 340, 350, and 355 nm, the fluorophores returned to their ground state giving off light (fluorescence). This fluorescence intensity (counts) varied and when captured using appropriate electronics, produced 1,024 pairs of light intensities (counts) and fluorescent wavelengths between 175 and 818 nm in 0.63 nm increments. Previous research indicated differences among diets could be determined using distinct peaks in the red and blue regions of the visible light spectrum and a univariate (1 variable at a time) analysis. This research demonstrates the entire fluorescence data set can be used to determine differences among diets using multivariate statistics. Sequences of 5 increasingly complex statistical techniques were used to distinguish among diets: 2-dimensional plots, polynomial regression models, confidence interval plots, discriminant analysis, and 3-dimensional plots. Two-dimensional plots indicated 2 spectral fluorescence peaks, 1 in the blue-green (420-600 nm) and 1 in the red (640-720 nm) region of the visible spectrum. Because of the asymmetrical nature of these peaks, fifth-order polynomials were developed to differentiate among the 4 diets. Statistical reliability was high when discriminating between diets containing no tarbush leaf and the diets containing 30% tarbush leaf; however, it was not possible to statistically separate diets containing intermediate (10 and 20%) amounts of tarbush leaf material from each other or from the 2 extremes (0 and 30% tarbush leaf). These results suggest spectral signatures arising from fluorometry data may be useful for differentiating among botanical composition diets that differ in plant form, but that a multivariate approach may require large sample sizes.
A proposed method for determining shrub utilization using (LA/LS) imagery
Authors: Quilter M. C. , Anderson V. J. ,   Society for Range Management
Published: March 2016

Utilization of plant above ground biomass has continued to be a critical yet difficult assessment in rangeland monitoring. Shrub size and woody structure further compound the measurement of shrub biomass utilization. This study was designed to determine the potential utility of low altitude/large scale (LA/LS) imagery in assessing shrub utilization. A near monoculture of Ceriotoides lanata (Pursh) J.T. Howell (winterfat) located in the western desert shrubland of Utah was used to evaluate this technique. Four, 3.1 by 3.1 m plots were identified and the shrubs within the plots were defoliated by hand-picking at about 10% intervals with imagery of the plots obtained between pickings. Imagery was obtained using a radio controlled airplane (drone) fitted with a 35 mm camera. Images were evaluated using image processing software and the resulting reflectance data correlated with defoliation percentages (weight basis) for each plot. Reflectance data from images correlated highly with defoliation percentages (r2 > 0.9). This technique of using LA/LS imagery shows promise for a quick and accurate tool in assessing utilization of shrubs.
Ranching motivations in 2 Colorado counties
Authors: Rowe H. I. , Bartlett E. T. , Swanson L. E. ,   Society for Range Management
Published: March 2016

The objectives of this Colorado study were to assess primary reasons ranchers choose to stay or sell the ranch, compare the motivations for ranching between a traditional agriculturally based county and a rapidly developing county, and assess whether factors such as length of tenure, fiscal dependency on ranching, and dependency on public lands play roles in decisions to sell. Personal interviews were conducted with 37 ranchers. While land use conversion occurs for a wide variety of reasons, lack of heirs and detrimental public policy were important reasons given for selling ranches. Responses showed Routt County (a rapidly developing county) ranchers were more likely to sell due to land use conversion related issues than Moffat County ranchers (p = 0.056). Ranchers with a longer legacy on their land reported that profitability, having likely heirs, and continuing tradition enhanced their reasons to stay. Groups more "at risk" of selling were non-homesteading ranchers close to retirement, larger ranches, and ranchers dependent on ranching for income with declining profits. Large ranch owners experiencing land use conflicts with non-ranchers and ranchers modestly dependent on public forage experiencing changes in public policy regulations and land use conflicts also indicated a higher proclivity to sell. Noting how groups of ranchers are impacted by different changes can help refine community efforts related to land use conversion and create more thoughtful policy measures.