• Evaluation of fecal indicators for assessing energy and nitrogen status of cattle and goats

      Nunez-Hernandez, G.; Holechek, J. L.; Arthun, D.; Tembo, A.; Wallace, J. D.; Galyean, M. L.; Cardenas, M.; Valdez, R. (Society for Range Management, 1992-03-01)
      In vivo digestibility trials involving cattle (steers) and goats (wethers) fed shrub and nonshrub mixtures were conducted to evaluate the potential of fecal output, fecal nitrogen output, and fecal nitrogen percent for assessing diet intake, nitrogen balance, and digestibility. Two cattle digestion trials involving 8 feeds and 4 goat digestion trials involving 13 feeds were used to develop simple linear and multiple regression equations between fecal and diet characteristics. Crude protein percent (organic matter basis) of cattle diets ranged from 3.9 to 12.0%; that of goats ranged from 7.5 to 14.4%. Low-phenolic and high-phenolic shrubs were fed in separate diets to goats while cattle diets involved only low-phenolic shrubs. Fecal output of organic matter (percentage of body weight) was correlated (r2>0.80) with forage organic matter intake (percentage of body weight) for both cattle and goats when all feeds were included in the regression. Linear regression intercepts, but not slopes, differed (P<0.05) among cattle and goats. Multiple regression equations did not improve evaluation of forage intake over simple linear equations using fecal output. Fecal nitrogen output (g N/kg BW) was associated more closely with nitrogen balance (g N/kg BW) than other fecal indicators. Further, fecal N output was best associated with nitrogen bahmce for both cattle and goats (r2 = 0.64, 73, respectively) when used in multiple regression equations. Multiple regression equations showed potential for evaluating nitrogen intake (g N/kg BW) of both cattle and goats, (R2 = 0.91, 0.87, respectively). Although it is doubtful that our equations have broad applications, our approach might be useful if specific equations were developed for individual range types.
    • Evaluation of microhistological analysis for determining ruminant diet botanical composition

      Alipayo, D.; Valdez, R.; Holechek, J. L.; Cardenas, M. (Society for Range Management, 1992-03-01)
      The accuracy of microhistological techniques for analysis of herbivore diets was evaluated with cattle, sheep, and Angora goats fed grass, forb, and shrub mixtures of known botanical compositions. Two observers performed microhistological analyses on undigested diets as offered and on feces collected. Similarity indices and chi-square tests were used to determine if differences existed among actual diets, estimated diets, and fecal samples. Botanical compositions of diets fed to all 3 animal species generally were accurately estimated by fecal analyses. In some other studies, shrubs in ruminant diets have been inaccurately estimated by the microhistological technique. However, in our study, shrubs were accurately estimated with no differences between actual and observed compositions. We attribute this to the fact that shrub materials used in our study had a high proportion of current growth relative to woody materials. Woody plant parts had lower proportions of identifiable epidermal material than leaves and young stems. In grass-forb diets, forbs sometimes were overestimated and differentiation among grasses was difficult. However, in most cases, observers could precisely estimate diets of the 3 herbivore species.
    • Jackrabbit densities on fair and good condition Chihuahuan desert range

      Daniel, A.; Holechek, J.; Valdez, R.; Tembo, A.; Saiwana, L.; Fusco, M.; Cardenas, M. (Society for Range Management, 1993-11-01)
      This study was conducted on Chihuahuan desert range near Las Cruces, in southcentral New Mexico, to determine the relationship of blacktailed jackrabbit (Lepus californicus) densities to good (GC) and fair (FC) range condition. The Soil Conservation Service procedure was used to classify ecological range condition. Line transect procedures were used to estimate jackrabbit populations from July 1988 to December 1990. Concurrently vegetation cover and mean plant height were determined with the line intercept procedure. Jackrabbit densities on the fair condition range were higher (P < 0.10) than those on the good condition range. This difference is attributed to the fair condition range containing more protective cover and preferred forage than good condition range. Jackrabbit abundance showed no season (P < 0.10) or year differences (P < 0.10). Jackrabbits preferred grass-shrub mosaic habitats more than shrubland and grassland habitats. The need for diverse food sources and protective cover were apparently major determinants of habitat selection by jackrabbits. The good condition range contained greater (P < 0.10) grass cover and less (P < 0.10) shrub cover than the fair condition range. Our results indicated that maintaining Chihuahuan desert ranges in good to excellent condition is the best means of achieving lower abundance of jackrabbit populations.
    • Legume Establishment on Strip Mined Lands in Southeastern Montana

      Holecheck, J. L.; Depuit, E. J.; Coenenberg, J. G.; Valdez, R. (Society for Range Management, 1982-05-01)
      Research was conducted on topsoiled strip mined lands at Colstrip, Mon., over a 6-year period to evaluate germination, survival, productivity, and cover characteristics of Eski sainfoin (Onobrychis viciaefolia), Lutana cicer milkvetch (Astragalus cicer), birdsfoot trefoil (Lotus corniculatus), and ranger and spreader alfalfa (Medicago sativa). Nitrogen and phosphorus fertilizer were applied at a low rate during the first year of study. None of the experimental units received irrigation. Lutana cicer milkvetch and both varieties of alfalfa demonstrated good establishment, survival, canopy cover, and productivity characteristics. Eski sainfoin showed good initial establishment but declined in following years. Birdsfoot trefoil appeared to be unsuitable for revegetation of mined lands at Colstrip. Spreader alfalfa was superior to ranger alfalfa in the parameters evaluated. Lutana cicer milkvetch showed much potential for mined lands revegetation in the study area because of site stabilization, persistence, palatability, nitrogen fixation, and productivity characteristics.
    • Long-Term Plant Establishment on Mined Lands in Southeastern Montana

      Holechek, J. L.; DePuit, E. J.; Coenenberg, J.; Valdez, R. (Society for Range Management, 1982-07-01)
      Research was conducted on strip mined lands at Colstrip, Mon., over a 6-year period to evaluate germination, survival and cover characteristics of fairway crested wheatgrass (Agropyron cristatum), critana thickspike wheatgrass (Agropgron dasystachyum), ranger alfalfa (Medicago sativa), and fourwing saltbush (Atriplex canescens). All 4 species showed good initial establishment and long-term survival/growth even though subjected to 2 consecutive years of drought when growing season precipitation was less than 50% of the mean. Nitrogen and phosphorus fertilizer application after emergence had no effect on initial or long-term survival of any species. However plant canopy and litter cover were increased for all species except fourwing saltbush by fertilizer application. There was little invasion of native species into the study area. Critana thickspike wheatgrass is a native species that appears well suited for seeding mixtures on mined lands in the study area. However, because of aggressiveness, the use of fairway crested wheatgrass is not recommended in mixtures from which a diversity of native species is the vegetation goal.
    • Magnification and Shrub Stemmy Material Influences on Fecal Analysis Accuracy

      Holechek, J. L.; Valdez, R. (Society for Range Management, 1985-07-01)
      When 100X and 200X microscope magnification levels were used singly and interchangeably in microhistological analysis, magnification level had no effect (P<.05) on diet botanical composition of 60% grass and 60% forb diets containing 6 forage species fed to mule deer. However, large differences occurred between magnification levels for individual plant species in a 60% shrub diet containing the same forage species. The use of the 100X and 200X magnification levels interchangeably was slightly more accurate than exclusive use of either magnification level for the high grass and high shrub diets. For fecal analysis our study shows 100X and 200X microscope magnification levels can be used singly or interchangeably with little influence on accuracy. Use of the 100X magnification level to scan fields for potentially identifiable fragments followed by switching to 200X magnification for better resolution of fragments difficult to discern can slightly improve both speed and accuracy. Fourwing saltbush, which had a high proportion of stemmy material relative to leaves, was severely underestimated in the feces of all 3 diets. Our data indicate fecal analysis has limited value as an estimator of diets of herbivores, such as mule deer, that consume significant but variable quantities of stemmy material from shrubs.
    • Mexico, Macro-Economics, and Range Management

      Molinar, Francisco; de Souza Gomes, Hilton; Holechek, Jerry L.; Valdez, R. (Society for Range Management, 1998-08-01)
    • Range condition influences on Chihuahuan Desert cattle and jackrabbit diets

      Daniel, A.; Holechek, J. L.; Valdez, R.; Tembo, A.; Saiwana, L.; Rusco, M.; Cardenas, M. (Society for Range Management, 1993-07-01)
      Knowledge of comparative diet selection by cattle and black-tailed jackrabbits (Lepus californicus) would permit better estimation of grazing capacity on Chihuahuan desert ranges. Cattle and black-tailed jackrabbit diets were evaluated seasonally on good and fair condition ranges over a 2-year period. Fecal samples analyzed by the microhistological technique were used to determine diets of both animals. Key forage species in cattle diets were dropseeds (Sporobolus sp.), black grama (Bouteloua eriopoda Torr.), leatherweed croton (Croton pottsii Lam.), and bush muhly (Muhlenbergia porteri Scribn.). Key forage species in jackrabbit diets were honey mesquite (Prosopis glandulosa Torr.), cactus (Opuntia sp.), dropseed, broom snakeweed (Gutierrezia sarothrae Pursh.), and black grama. Overall diet botanical composition data showed cattle consumed 58% grass compared to 22% for jackrabbits (P < 0.05). Forb consumption was similar between the 2 animals and averaged about 31%. Shrub consumption averaged 47% and 12% for jackrabbits and cattle, respectively (P < 0.05). Range condition did not influence total grass consumption by either animal. Both animals, however, had lower forb and higher shrub consumption on fair compared to good condition range. Overall dietary overlaps between jackrabbits and cattle were 40 and 42% on good and fair condition ranges, respectively. Poisonous plants contributed up to 14 and 36% of cattle and jackrabbit diets, respectively. Data from this study show little forage competition occurs between cattle and jackrabbits when stocking rates and jackrabbit numbers are moderate. Several plants poisonous and unpalatable to cattle were important jackrabbit foods. These plants were more prevalent on the fair compared to the good condition range.
    • Research observation: Desert bighorn sheep diets in northwestern Sonora, Mexico

      Tarango, L. A.; Krausman, P. R.; Valdez, R.; Kattnig, R. M. (Society for Range Management, 2002-11-01)
      We used microhistological analyses of fresh fecal pellets to determine seasonal diets of desert bighorn sheep (Ovis canadensis mexicana Merriam 1901) in northwestern Sonora, Mexico from April 1997 to December 1998. We identified 41 plant species (22 browse, 10 forbs, 5 grasses, and 4 succulents) in diets of bighorn sheep. We found no differences between diets of males and females, and diet diversity between sexes was similar (P 0.05). Diet included: browse (45.7%), forbs (32.0%), succulents (17.8%), and grasses (4.5%). The consumption of succulents was higher during spring, decreased during summer, increased in autumn, and decreased in winter. Consumption of forbs was higher during winter and summer. Globemallow (Sphaeralceae spp.), desert agaves (Agave spp.), range ratany (Krameria parvifolia Benth.), buck-wheatbrush (Eriogonum spp.), foothill palo verde (Cercidium microphyllum [Torrey] Rose Johnst.), Engelmann prickly pear (Opuntia engelmanii Salm-Dyck), desert ironwood (Olneya tesota A. Gray), and elephant tree (Bursera microphylla A. Gray) were consumed throughout the study. As biologists identify potential release sites for restoration of bighorn sheep in Mexico, studies of diet composition will provide managers with information for successful translocations.
    • Research observation: Effects of rangeland ecological condition on scaled quail sightings

      Joseph, J.; Holechek, J. L.; Valdez, R.; Collins, M.; Thomas, M. (Society for Range Management, 2003-07-01)
      Scaled quail (Callipepla squamata) numbers were evaluated during and after a 2-year drought period using strip census techniques on 2 pastures in late seral rangeland ecological condition and 2 pastures in mid-seral rangeland ecological condtion. This study was conducted on the Chihuahuan Desert Rangeland Research Center (CDRRC) in south-central New Mexico on 4 adjoining pastures that were similar in size and terrain. During part of the study (August 1994 to April 1997) all 4 pastures were destocked due to depletion of perennial grass cover and biomass from a combination of drought and heavy cattle grazing. Scaled quail sightings pooled across sampling periods (9) were different (P = 0.08) on high and low rangeland ecological condition treatments. They averaged 10.72 birds per pasture on late-seral and 4.22 birds per pasture on mid-seral rangeland ecological condition treatments. Autumn perennial grass cover and standing biomass levels was higher (P < 0.10) on late seral than on mid-seral rangeland ecological condition pastures during both years of study. Availability of scaled quail foods such as leatherweed croton and broom snakeweed did not differ (P > 0.10) between treatments. Our study indicates that during extended dry periods livestock grazing at moderate intensities may adversely affect scaled quail populations in the Chihuahuan Desert by depleting perennial grass cover. However, in years of above average precipitation there is evidence scaled quail prefer mid-seral pastures over late-seral pastures. Maintaining a mosaic of conservatively (late-seral) and moderately (mid-seral) grazed pastures should best meet the habitat needs of scaled quail in the Chihuahuan Desert.
    • Seeded wheatgrass yield and nutritive quality on New Mexico big sagebrush range

      Holechek, J. L.; Estell, R. E.; Kuykendall, C. B.; Valdez, R.; Cardenas, M.; Nunez-Hernandez, G. (Society for Range Management, 1989-03-01)
      Establishment, yield, and nutritional quality of 'Nordan' crested wheatgrass (Agropyron desertorum [Fischer ex Link] Schultes), 'Fairway' crested wheatgrass (Agropyron cristatum [L.] Gaertner), 'Arriba' western wheatgrass (Pascopyrum smithii [Rydb.] A. Love), 'Luna' pubescent wheatgrass (Thinopyrum intermedium subsp. barbulatum [Schur.] Barkw. and D.R. Dewey), and 'Largo' tall wheatgrass (T. ponticum [Pod] Barkw. and D.R. Dewey) were evaluated on big sagebrush range (Artemisia tridentata Nutt. tridentata) in northcentral New Mexico during a 5-year study. All the above wheatgrasses showed high initial densities and long-term persistence. Wheatgrass yields across years and seasons during the last 2 years of study averaged 760 kg/ha compared to forage yields of 355 kg/ha on surrounding ungrazed native rangeland. There were no differences (P > .05) among wheatgrasses in standing crop of current year's growth during spring, summer, or fall. Crude protein concentrations did not differ (P > .05) among wheatgrasses with seasonal advance. However, all the wheatgrasses showed a consistent decline in nutritional quality from spring to summer to fall. All the wheatgrasses we studied will provide high-quality, spring (mid-April to mid-June) forage for livestock. During summer, use of native range is advantageous because it contains a high component of warm season grasses and forbs. Interseeding shrubs in wheatgrass seedings could reduce protein supplementation costs in winter.
    • Wildlife numbers on late and mid seral Chihuahuan Desert rangelands

      Nelson, T.; Holechek, J. L.; Valdez, R.; Cardenas, M. (Society for Range Management, 1997-11-01)
      Seasonal wildlife observations were made along transects on 2 pastures in late seral and 2 pastures in mid seral condition in southcentral New Mexico in non-drought and drought years (1993, 1994). Remaining climax vegetation was about 64% and 57% on late seral pastures. About 37% and 32% of the climax vegetation remained on mid seral pastures. Total wildlife and total bird sightings/km2 during the study period were higher (P < 0.10) on the mid compared to late seral rangelands. The same number of wildlife species were seen on the late and mid seral pastures. Sightings of scaled quail (Callipepla squamata Vigors), mourning doves (Zenaida macroura Linnaeus), prong-horn (Antilocapra americana Ord), and desert cottontails (Sylvilagus auduboni Mearns) showed no differences (P> 0.10) between late and mid seral condition rangelands. Black-tailed jackrabbit (Lepus californicus J.A. Allen) numbers were higher (P