Welcome to the Rangeland Ecology & Management archives. The journal Rangeland Ecology & Management (RE&M; v58, 2005-present) is the successor to the Journal of Range Management (JRM; v. 1-57, 1948-2004.) The archives provide public access, in a "rolling window" agreement with the Society for Range Management, to both titles (JRM and RE&M), from v.1 up to five years from the present year.

The most recent years of RE&M are available through membership in the Society for Range Management (SRM). Membership in SRM is a means to access current information and dialogue on rangeland management.

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Print ISSN: 0022-409x

Online ISSN: 1550-7424


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Recent Submissions

  • Woody and herbaceous aboveground production of a Patagonian steppe

    Fernández-A., R. J.; Sala, O. E.; Golluscio, R. A. (Society for Range Management, 1991-09-01)
    Aboveground net primary production (ANPP) of the Patagonian steppe in southwestern Chubut (Argentina) was estimated using a harvest technique to assess the herbaceous (mainly grass) component and a double sampling technique to evaluate shrub production. The latter requires the measurement of plant dimensions and the harvest of shrub biomass in small plots. This technique, by virtue of having an explicit biological model which considers both shrub size and production per unit surface of plant, allows comparisons among years, sites, and treatments. Detailed estimates of ANPP yielded a value of 79 g of dry matter (DM) m-2 yr-1 (SE = 19 g DM m-2 yr-1) for an annual rainfall of 191 mm. Our estimates fits (+/- 17%) predictions of 4 models relating primary production to annual precipitation. Two thirds of production were accounted for by perennial grasses and one third by shrubs. A less detailed method, which uses only peak biomass, gave ANPP estimates for 4 additional years ranging from 21 to 75 g DM m-2 yr-1 while annual precipitation during this period ranged from 55 to 167 mm. There was a large reduction in ANPP during a year of extreme drought; however, there were no increases in ANPP during years with above-average precipitation. This suggests that the carrying capacity for the Patagonian steppe may not be linearly related to precipitation.
  • Variability of near-surface soil temperature on sagebrush rangeland

    Pierson, F. B.; Wight, J. R. (Society for Range Management, 1991-09-01)
    Models used to simulate plant growth and insect development on rangelands often assume that soil temperature is homogeneous over the entire area of interest. This simplifying assumption is made because few data are available on the magnitude and structure of the spatial variability of soil temperature within rangeland communities. The influence of sagebrush on the spatial variability and diurnal fluctuations of near-surface soil temperature was examined within a sagebrush-grass plant community. Hourly soil temperatures were measured at 1-, 5-, and 10-cm depths at 30-cm intervals along a 12.3-m north-south transect over a 6-day period in March, 1989. Both classical and geostatistical techniques were used to quantify and model the magnitude and structure of the spatial and temporal variability. Maximum soil temperatures at the 1-cm depth varied from 7 to 23 degrees C under sagebrush and bare interspace, respectively. Periodic spatial patterns in soil temperature were found for all measured depths with a wavelength of periodicity approximately equal to the separation distance between sagebrush plants along the transect. Diurnal variability in near surface soil temperature was much greater in interspace areas compared to under sagebrush plants. The amplitude of diurnal variability in soil temperature at the 1-cm depth under sagebrush was similar to the amplitude of the diurnal variability at the 10-cm depth within the interspaces.
  • Utilization patterns by Angora goats within the plant canopies of two Acacia shrubs

    Owens, M. K. (Society for Range Management, 1991-09-01)
    Uneven distribution of livestock in large pastures results in some areas receiving more use than the average and some areas receiving little or no use. Six 2-ha experimental pastures on a shallow ridge site were stocked with 2, 4, or 6 Angora goats per ha to reflect different levels of use found in large pastures of south Texas. Two additional pastures on a sandy loam site were stocked with 2 goats per ha. Utilization estimates were made in each pasture using a twig diameter-weight relationship. Estimates of utilization of guajillo (Acacia berlandieri) and blackbrush (A. rigidula) were made in canopy strata which the goats could reach in a quadrupedal stance (low), a bipedal stance (middle), and from the zone above the bipedal stance (high). These measurements were repeated 3 times during the grazing season. Nonlinear regressions of diameter on weight (Y = aXb) collected from plants in control pastures provided a better fit than log-log regressions in almost every instance. Fit index values, which are analogous to R2 values for linear equations, ranged from 0.82 to 0.94 for nonlinear equations and from 0.62 to 0.88 for the log-log regressions. Goats exhibited different grazing strategies by using the canopy strata differently for the 2 plant species. Percent utilization in the middle strata was higher than in either of the other 2 canopy strata within each grazing treatment and for each plant species. Cumulative use in the middle strata for guajillo was 79% compared to 63% in the low and 28% in the high strata. Blackbrush also had highest use in the middle strata with 39% use compared to 27 and 9% for the low and high canopies, respectively. By the third sampling period, use of guajillo in the 2 lowest canopy strata declined and use of blackbrush increased over the first 2 sampling periods. Average grazed twig diameter within each grazing treatment did not vary significantly in the low strata throughout the growing season. On heavily used sites, averaged grazed twig diameter increased in the 2 highest canopy layers as the season progressed. The size of grazed twigs in the middle zone on the heaviest grazed sites was significantly higher than in any other canopy strata.
  • Technical Note: Mineral content of guajillo regrowth following roller chopping

    Fulbright, T. E.; Reynolds, J. P.; Beasom, S. L.; Demarais, S. (Society for Range Management, 1991-09-01)
    Guajillo (Acacia berlandieri Benth.) is browsed by white-tailed deer (Odocoileus virginianus Raf.). We determined phosphorus (P), potassium, (K), calcium (Ca), and magnesium (Mg) of browse from roller-chopped (July 1986 and July 1987) and nontreated guajillo. Browse from regrowth was temporarily higher in P than browse from nontreated plants. Potassium was higher in leaves from plants roller chopped in 1987. Calcium and Mg tended to be lower in leaves from roller-chopped plants. Roller chopping temporarily increases P and K, but whether or not browse from roller-chopped guajillo meets P and K requirements for deer is unknown.
  • Stable states and thresholds of range condition on North American rangelands: A viewpoint

    Laycock, W. A. (Society for Range Management, 1991-09-01)
    The concepts of relatively stable multiple states and thresholds or transitions between these states has received little attention in range management until recently. On North American rangelands lower successional stable states occur in sagebrush and other shrub-dominated vegetation types in the Great Basin, the shortgrass steppe, the Southwestern desert grasslands, and communities dominated by annual grasses in California and southern Idaho. Recognition of these stable states and models describing them are needed to develop new concepts about range condition. The model presently used assumes a single stable state (climax) and that the stages of secondary succession on improving rangelands are the reverse of the stages of retrogession. Alternative models presented include the 'cup in ball' analogy, the state-and-transition model, and others. While much theoretical work needs to be done before any of these models can be incorporated into range condition standards, it is important for range managers to recognize that multiple steady states exist for many vegetation types. One assumption of the current range condition model is that a reduction in grazing pressure and an improvement in grazing management will result in range improvement. If a vegetation type is in a stable lower successional state, it normally will not respond to change in grazing or even removal of grazing. Managers must recognize this situation when it occurs so that false expectations of improvement are not fostered.
  • Risk of predation and food consumption by black-tailed jackrabbits

    Longland, W. S. (Society for Range Management, 1991-09-01)
    Vegetation cover may afford many species of prey animals reduced risk of being detected and/or attacked by predators. In this study, feeding stations were provided for black-tailed jackrabbits (Lepus californicus) at 3 distances from perennial shrubs to test the prediction that the intensity of foraging by these hares would subside as they moved away from the presumed safety of shrub cover. Jackrabbits consumed significantly more food at stations under shrub canopies than at stations 5 and 10 m from shrubs. Thus, results are consistent with the hypothesis that risk of predation constrains the foraging activities of jackrabbits. The two-fold increase in food consumption near shrubs as compared with consumption away from shrubs implies that native plants or agronomic crops should incur lower levels of herbivory by jackrabbits when they occur at some distance from protective cover.
  • Range condition assessment and the concept of thresholds: A viewpoint

    Friedel, M. H. (Society for Range Management, 1991-09-01)
    Dissatisfaction persists with current approaches to range condition and trend assessment. Sometimes assessed condition does not truly represent the past or the potential of range. One of the likely causes is a failure to re-examine and change if necessary the theoretical basis of assessment, in line with developing understanding of ecological processes. The concept of thresholds of environmental change appears to provide a reasonable alternative in some circumstances to the concepts of gradual retrogression and secondary succession which are currently accepted. I suggest that environmental change can be discontinuous, with thresholds between alternative states. Once it threshold is crossed to a more degraded state, the former state cannot be attained without significant management effort, such as prescribed burning, ploughing, or herbicide application, rather than simple grazing control. Examination of data from extensive monitoring programs and from a study of grazing impact, as well as more general sources of information, indicates that thresholds of change may be identifiable in arid rangelands. A practical means of monitoring proximity to thresholds is available and, with the aid of multivariate analysis, the effects of spatial variability and season can be separated from those of management. The potential of this approach deserves investigation in a wider variety of environments.
  • Preference of wintering sage grouse for big sagebrush

    Welch, B. L.; Wagstaff, F. J.; Roberson, J. A. (Society for Range Management, 1991-09-01)
    A study determined sage grouse (Centrocercus urophasianus) preference for 3 subspecies and 9 accessions of big sagebrush (Artemisia tridentata Nutt.). The subspecies were mountain big sagebrush (A.t. ssp. vaseyana Rydb. Beetle), Wyoming big sage-brush (A.t. ssp. wyomingensis Beetle and Young), and basin big sagebrush (A.t. ssp. tridentata Nutt.). Accessions were collected at various sites in Utah and established in a uniform garden. Eleven plants for each accession or 33 plants for each subspecies were planted at random on a 2.13-m grid for a total of 99 plants. An enclosure with a top was constructed. Six birds were captured and placed in the garden. Preference was measured by the number of bites taken during the study and by estimates of percentage of leaves eaten at the end of the study. Results, by order of preference, were mountain big sagebrush, Wyoming big sagebrush, and basin big sagebrush. Within the most preferred subspecies there was distinct preference among accessions as measured by bite counts. When the forage of preferred subspecies or accessions was exhausted, the birds readily ate other subspecies or accessions.
  • Overgrazing: Present or absent?

    Wilson, A. D.; MacLeod, N. D. (Society for Range Management, 1991-09-01)
    This paper discusses the criteria needed for quantitative evidence of overgrazing and outlines some of the main pasture and external factors that promote overgrazing by herbivores. Overgrazing is defined as occurring where there is a concomitant vegetation change and loss of animal productivity arising from the grazing of land by herbivores. Confirmation of the loss of productivity requires the measurement of departures from the linear relationship between animal productivity and stocking rate for any given animal-pasture system. In the ex-ante situation of an experiment, overgrazing will be observed as a loss of linearity with time. in the ex-poste situation of a comparison between 2 paddocks of the some range type, but different grazing history, overgrazing will be observed as a difference in the optimum stocking rate. The outcome of a species change in terms of productivity is shown to be complex because of the interaction of the quality and quantity influences in both pasture and product. Influences that promote lower stocking rates include low cost-price margins and a negative relationship between product quality and grazing intensity. Conversely, higher stocking rates are promoted by the use of mineral supplements and products such as wool that have a positive relationship between product quality and stocking rate.
  • Mountain mahogany and cottonseed meal as supplements for grass hay

    Nunez-Hernandez, G.; Wallace, J. D.; Holechek, J. L.; Galyean, M. L.; King, D. W.; Kattnig, R. M. (Society for Range Management, 1991-09-01)
    Sixteen wether lambs (avg weight 34.5 kg) were used to study the influence of 2 sources of supplemental protein, leaves of mountain mahogany (Cercocarpus montanus Raf.) and cottonseed meal, on N digestibility and balance, forage digestibility, and voluntary intake by sheep fed a low-quality grass hay. Treatments were grass hay alone (C), C plus cottonseed meal, C plus mountain mahogany, and C plus mountain mahogany and cottonseed meal. All supplements provided 42 g of supplemental crude protein per head daily. Treatments were assigned to wethers within blocks according to a randomized complete block design. Supplemental N increased (P < 0.01) N digestibility and balance regardless of source; however, lambs supplemented with mountain mahogany digested less (P < 0.01) N, but their N balance did not differ (P > 0.10) from those supplemented with cottonseed meal. Wethers supplemented with mountain mahogany plus cottonseed meal ate more (P < 0.05) organic matter (OM) than the average consumed by those given either of the 2 supplements alone. Protein supplementation did not affect (P > 0.05) OM or fiber digestibility. Range management practices that encourage dormant season utilization of mountain mahogany by ruminants in the Southwest could reduce supplemental protein needs; such practices might include reserving mountain mahogany sites for winter use as well as greater use of mountain mahogany (and other palatable, highly nutritive shrubs) in range restoration programs in mountainous areas.
  • Mefluidide effect on weeping lovegrass heading, forage yield, and quality

    White, L. M. (Society for Range Management, 1991-09-01)
    Weeping lovegrass [Eragrostis curvula (Schrad.) Nees.] provides high quality forage during May, but growth of floral stems causes a rapid decline in forage quality. The study objective was to determine which combination of date and rate of mefluidide [N-(2,4-dimethyl-5-[(trifluoro methyl) sulfonyl]amino]phenyl)acetamide], a growth regulator, would effectively decrease number of floral stems and thus maintain higher forage quality. Mefluidide (0.00, 0.28, 0.56, and 0.84 kg/ha) was applied to lovegrass on 1 of 3, 2, 5, and 5 dates in 1984, 1985, 1986, and 1987, respectively. Lovegrass was grown on a Pratt fine sandy loam (Thermic Psammentic Haplustalf) soil near Woodward, Okla. Factorial combinations of treatments were rerandomized within the study area each year. Plots (1.8 by 5 m) were replicated 6 times in a randomized complete block design. Forage was harvested in mid June to early July with a sickle bar at seed ripe. Mefluidide reduced the number of floral stems only when applied 1 week after floral primordium initiation. Mefluidide application 1 week earlier or later had little effect on number of floral stems, forage yield, in vitro dry matter digestibility (IVDMD), or crude protein (CP). Application of 0.56 kg/ba of mefluidide 1 week after floral primordium initiation decreased number of floral stems 58 to 93%, decreased forage yield 14 to 23%, increased percent leaves 4 to 32 percentage units, and had little effect on leaf yield. It increased whole-plant IVDMD 1.6 to 2.8 and CP 0.2 to 1.6 percentage units depending upon year. Generally, mefluidide had tittle effect on leaf or stem IVDMD or CP that averaged 49 and 7.5% for leaves and 39 and 5.1% for stems, respectively. The effective 'window' for mefluidide application is probably too short for practical use by farmers or ranchers.
  • Interference between yellow starthistle and pubescent wheat-grass during grass establishment

    Prather, T. S.; Callihan, R. H. (Society for Range Management, 1991-09-01)
    Yellow starthistle (Centaurea solstitialis L.) and pubescent wheatgrass (Thinopyrum intermedium spp. barbulatum (Schur) Barkw. & D.R. Dewey) were seeded and subsequently thinned to 0, 130, 260, and 390 plants/m2 in a factorial arrangement. Aggressivity coefficients indicated that intraspecific interference became stronger than interspecific interference, based on biomass of either pubescent wheatgrass and yellow starthistle, as the density of both species increased in a 1:1 ratio. Pubescent wheatgrass provided 0.5 to 1.3 times as much intraspecific interference, plant for plant, as the interspecific interference caused by yellow starthistle. Yellow starthistle provided from 1.5 to 4.6 times as much intraspecific interference, plant for plant, as the interspecific interference caused by pubescent wheatgrass. Weekly leaf counts showed that intra- and interspecific interference from yellow starthistle was detectable 6 weeks after emergence. Weekly leaf counts showed that intraspecific interference from pubescent wheatgrass was detectable 7 weeks after emergence; interspecific interference from pubescent wheatgrass was not detectable using leaf count comparisons. Soil moisture at a 10 cm depth was correlated to leaf number of pubescent wheatgrass but not with leaf number of yellow starthistle. This may reflect the greater competitive ability of yellow starthistle.
  • Importance of hypocotyl hairs in germination of Artemisia seeds

    Young, J. A.; Martens, E. (Society for Range Management, 1991-09-01)
    The nature and function of hairs that occur on the lower portion of the hypocotyl of juvenile Artemisia seedlings was investigated. Our purpose was to determine if these hairs served an important function in seedling establishment of these species, which are often difficult to establish by direct seeding. The hypocotyl hairs occurred in a number of Artemisia species. The hairs form a dense ring around the bottom of the hypocotyl and the radicle emerges through the ring. Apparently, the function of the hairs is to attach the juvenile seedling to the surface of the germination substrate, which may aid in the penetration of the radicle into the substrate. Scanning electron microscope images of the hypocotyl hairs revealed the occurrence of mucilage which may aid in attaching the hairs to the substrate. In most studies, the seedling and breaking the contact of the hypocotyl hairs to the substrate reduced seedling survival and increased the number of surviving seedlings with abnormal geotropism.
  • Grazing effects and range trend assessment on California bighorn sheep range

    Wikeem, B. M.; Pitt, M. D. (Society for Range Management, 1991-09-01)
    This study investigated the effect of grazing by California bighorn sheep (Ovis canadensis californiana) on plant community structure. Over 28 months from 1977 to 1979, bighorn diet consisted of 79 species, including 14 grasses, 47 forbs and bryophytes, plus 18 trees and shrubs. Grasses, forbs, and shrubs comprised 66.6, 18.9, and 14.5% of the diet, respectively. Three years of bighorn sheep grazing reduced (P < 0.05) leaf and culm lengths of bluebunch wheatgrass (Agropyron spicatum (Pursh) Scribn. & Smith). Grazing generally reduced leaf length, basal diameter, culm (stem) length, and culm (stem) numbers of prairie Junegrass (Koeleria cristata Pers.), Sandberg's bluegrass (Poa sandbergii Vasey), needle-and-thread (Stipa comata Trin. & Rupr.), Thompson's paintbrush (Castilleja thompsonii Pennell), silky lupine (Lupinus sericeus Pursh), and snow buckwheat (Eriogonum niveum Dougl.). Vigor of arrowleaf balsamroot (Balsamorhiza sagittata (Pursh) Nutt.) was unaffected by grazing, despite its dietary importance. Total plant frequency remained unchanged between 1976 and 1983 in areas grazed by bighorn sheep, and in grazing exclosures. Total grass frequency declined from 46.5 to 30.8% within the exclosures, but increased from 44.7 to 48.8% in response to bighorn sheep grazing. Forb frequency remained unchanged after 7 years of bighorn sheep grazing while frequency of yarrow (Achillea millefolium L.) increased more inside exclosures than on the grazed area. Botanical composition of shrubs increased on grazed and ungrazed areas from 1976 to 1983, but frequency was unaffected by bighorn sheep grazing. Snow buckwheat and Wyeth buckwheat (Eriogonum heracleoides Nutt.) declined in response to bighorn sheep grazing. Successional trends caused by California bighorn sheep grazing differed from trends expected from cattle grazing.
  • Genetic variances for dry matter yield, nitrogen content, and nitrogen yield in crested wheatgrass-alfalfa mixtures

    Asay, K. H.; Mayland, H. F. (Society for Range Management, 1991-09-01)
    Since its introduction from Asia in the early 1900s, crested wheatgrass [Agropyron cristatum (L.)Gaertner, A. desertorum (Fisch. ex Link) Schultes et al.] has had a major impact on the improvement of western rangelands of North America. Most of the early seedings with this cool-season grass were made as monocultures. Present and projected use of rangelands, however, prescribe that future crested wheatgrass cultivars have the genetic potential to be an effective component in a species complex including other grasses, shrubs, and forbs. The present study was conducted to evaluate the effect of associated alfalfa (Medicago sativa L.) on the performance and genetic variability in a 50-clone sample of a tetraploid crested wheatgrass breeding population. Significant (P < 0.05) differences were found among the clonal lines for dry matter (DM) yield, nitrogen (N), and N yield. Opportunities for genetic improvement, as indicated by the magnitude of the genetic variation for these characters, was significantly increased when the grasses were grown in association with alfalfa. Significant (P < 0.01) and positive correlations of clonal means between stand types indicated that differences among the clonal lines in DM yield, N content, and N yield were relatively consistent when grown with or without alfalfa. These results indicate that initial screening could be effectively done in tetraploid crested wheatgrass in the presence or absence of alfalfa. Final evaluation of breeding lines and experimental strains, however, should be done with alfalfa if the object is to develop cultivars to be grown in combination with that species.
  • Forest Service and livestock permitee behavior in relation to wildness designation

    McClaran, M. P. (Society for Range Management, 1991-09-01)
    Even though the Wilderness Act of 1964 provided for continuation of livestock grazing after wilderness designation, there has been continued debate about the Forest Service's implementation of this provision and the impact on livestock grazing permittees. The effect of wilderness designation, during the first 20 years after designation, on Forest Service and permittee behavior on Coronado and Tonto National Forests in Arizona was evaluated by (1) comparing changes in permitted AUMs, changes in permit ownership, and proportion of nonuse of permitted AUMs between paired wilderness and nonwilderness grazing allotments, and (2) assessing the importance of the proportion of an allotment in wilderness on these same behavioral parameters. In general, permitted AUMs increased on wilderness allotments but remained the same for nonwilderness allotments. However, there was no difference on Coronado National Forest when forests were analyzed separately. Compared to nonwilderness allotments, wilderness allotments had greater permittee turnover on Coronado National Forest, but there were no differences between wilderness and nonwilderness allotments when forests were combined. The higher the proportion of an allotment in wilderness, the faster the turnover of permit owners, but wilderness proportion did not affect nonuse or changes in permitted AUMs.
  • Forage yield and white-tailed deer diets following live oak control

    Fulbright, T. E.; Garza, A. (Society for Range Management, 1991-09-01)
    Live oak (Quercus virginiana Mill.) competes with herbaceous plants, but provides browse and mast for white-tailed deer (Odocoileus virginianus Zimmerman). We determined the effects of treating live oak with tebuthiuron on yield of herbaceous vegetation and white-tailed deer diets and nutritional indices. In 1982, 259 ha were aerially treated with 2.2 kg/ha active ingredient of tebuthiuron pellets in parallel, alternating treated and untreated strips, each measuring 76 m wide. A second area was treated in 1984. We clipped herbage during June and November 1985-86 within exclosures in treated and untreated strips, and determined chemical and botanical composition of rumen contents and kidney fat index (KFI) from deer killed in the 1982 strip treatment area and a control (untreated) area. Grass yield was 2-4 times higher on treated thin on untreated range. Forb yield was almost 5 times greater on range treated in 1982 than on untreated range, but yield on untreated range and areas treated in 1984 was similar. Deer sampled in the control ares had consumed more forbs than those sampled in the herbicide-stripped area except in fall 1985. The KFI was greater for deer sampled in the control area in fall 1985 and greater for those sampled in the stripped area in fall 1986. Treatment with tebuthiuron in alternating strips increased forage yield for cattle and was apparently not detrimental to KFI of deer.
  • Effects of seasonal rest in aboveground biomass for a native grassland of the flood Pampa, Argentina

    Hidalgo, L. G.; Cauhépé, M. A. (Society for Range Management, 1991-09-01)
    Changes in total biomass and botanical composition in a native pasture of the Flooding Pampa in the Salado River Basin (Province of Buenos Aires), under 3 grazing systems: spring-summer rest (November, December, and January); fall rest April, May, and June), and continuous grazing were evaluated from October 1979 to August 1981. A variable stocking rate based on available forage was used. Total aboveground biomass was periodically sampled to ground level and separated into dead and green components. The green biomass was subdivided into individual species. Total aboveground biomass averaged 4,600 +/- 445 kg ha-1 and 3,750 +/- 120 kg ha-1 for the spring-summer rest treatment during the first and second years, respectively. In the same period, warm-season species increased, principally due to an increase in dallisgrass (Paspalum dilatatum Poir.) and bluestem (Bothriochloa laguroides Herter) biomass. Total aboveground biomass yield was 2,000 +/- 170 kg ha-1 during the fall rest treatment, and cool-season species such as Poa spp. and Stipa spp. increased. In general, continuous grazing at a moderate intensity resulted in total aboveground biomass of about 2,000 kg DM ha-1 throughout the experimental period. Contributions of warm-season and cool-season species did not change. Only West Indies smutgrass (Sporobolus indicus (L.) R. Br.) increased under continuous grazing.
  • Diet sample collection by esophageal fistula and rumen evacuation techniques

    Olson, K. C. (Society for Range Management, 1991-09-01)
    Two trials were conducted to compare diet samples collected in the evacuated rumen or through the esophageal fistula. Hypotheses tested were (1) rumen evacuation would not decrease selectivity, (2) being in the rumen during collection would not alter the sample, and (3) both techniques accurately estimated nutritional characteristics of the feed offered. Five steers bifistulated at the esophagus and rumen were used in a grazing and a stall trial. Three collection techniques were used in each trial: rumen collection after evacuation (RC), esophageal collection with the rumen evacuated (ECRE), and esophageal collection with the rumen full (ECRF). Comparison of RC and ECRE assessed the influence of being in the rumen, and ECRE vs ECRF tested selectivity. Hay was sampled before feeding in the stall trial to test hypothesis 3. All samples were analyzed for organic matter (OM), nitrogen (N), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), hemicellulose, and cellulose. In the grazing trial, collection technique affected only ADL (P = 0.05), with ECRE depressed compared to ECRF. Organic matter, N, ADL, and hemicellulose responded (P < 0.05) during the stall trial as follows. Salivary ash contamination depressed OM (P = 0.03) in all collected masticate compared to the feed offered. Rumen collection elevated N (P = 0.04), but esophageal samples and feed were equal. Hemicellulose was depressed slightly (P = 0.01) in all collected masticate. Both techniques elevated ADL (P = 0.001), with RC having a greater effect than ECRF. Both collection techniques should provide satisfactory results in grazing trials if precautions are taken. Comparison across techniques appears appropriate if caution is exercised, particularly concerning N and ADL.

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