Manuel Cardenas
New Mexico State University
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Journal of Range Management | 1992
Daniel Alipayo; Raul Valdez; Jerry L. Holechek; Manuel Cardenas
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.
Journal of Range Management | 1995
Michael Fusco; Jerry L. Holechek; Ackim Tembo; Alpiayou Daniel; Manuel Cardenas
Long-term influences of livestock grazing on vegetation around watering points was studied on 2 upland Chihuahuan desert ranges in southcentral New Mexico using regression analysis. One range had been conservatives stocked since the 1950s while the other was more heavily stocked. About 45% of the climax vegetation occurred on the heavily stocked range compared to 70% on the conservatively stocked range. During 3 years of study, both ranges were stocked conservatively so annual utilization of the key forage grasses was 30-35%. Regression analyses showed black grama (Boueteloua eriopoda Torr.), mesa dropseed (Sporobolus flexuosus Thurb, Rybd.), threeawn (Aristida sp.), and total perennial grass standing crop increased as distance from water increased on the good condition range (P < 0.05). However, black grama and threeawn standing crop showed no association with distance from water on the fair condition range. Broom snakeweed (Xanthocephalum sarothrae Pursh.), the primary poisonous plant found on both ranges, was associated (r2 = 0.35) with distance from water only on the good condition range in April. Poisonous plants other than broom snakeweed decreased as distance from water increased with the exception of the fair condition range in October. No livestock losses from poisonous plants were noted on either range over the 3 years. We attribute this to the present conservative stocking rates. Our study supports the recommendation that downward stocking rate adjustments be made for the zone more than 1,600 m from water.
Journal of Range Management | 1989
Gregorio Nunez-Hernandez; Jerry L. Holecheck; Joe D. Wallace; M. L. Galyean; Ackim Tembo; Raul Valdez; Manuel Cardenas
In vivo digestibility trials were conducted to evaluate the influence of shrubs containing low and high levels of soluble phenolic/tannins on digestibility and nitrogen retention by Angora goats. Each of 6 shrubs and alfalfa hay (Medicago sativa L.) were fed to goats at 30% (dry matter basis) of the diet in a barley straw-prairie hay mixture. The mixture was regulated so that all diets contained about 8% crude protein. High soluble phenolic shrubs used included big sagebrush (A rtemisia tridentata Nutt. ssp. tridentata), gray oak (Quercus grisea Liebm.), true mountain mahogany (Cercocarpus montanus Raf.), and one-seed juniper (Juniperus monosperma [Engelm.] Sarg). Low-soluble phenolic species included common winterfat (Ceratoides lanata [Pursh.], J.T. Howell), fourwing saltbush (A triplex canescens [Pursh.], Nutt.), and alfalfa. Nitrogen digestibilities of winterfat, gray oak, mountain mahogany and one-seed juniper diets were less (P .05) compared with the alfalfa control. Retained nitrogen (g/d) differed (P<.05) only among alfalfa, juniper, and mountain mahogany diets. Goats fed juniper had greater (P<0.05) retained nitrogen than the alfalfa control. Shrubs high in soluble phenolics, with the exception of big sagebrush, had elevated fecal nitrogen losses, but reduced urinary nitrogen losses compared with the alfalfa control. Forage organic matter intake (% body weight) and nitrogen intake (g/d) were correlated more highly with nitrogen retention than dietary crude protein (%) or digestible protein (%). Present data indicate that protein found in palatable native shrubs is assimilated with similar efficiency to that in alfalfa hay if these shrubs are consumed at
Journal of Range Management | 1985
Helen Wofford; Jerry L. Holechek; M. L. Galyean; Joe D. Wallace; Manuel Cardenas
A study involving 6 feeds of widely varying chemical properties fed to 6 steers in a Latin square design was conducted to evaluate the potential of fecal chemical characteristics for predicting ruminant nutritional status. Forage intake, diet in vivo digestibility %, and diet nitrogen % were used as dependent variables and fecal nitrogen %, nucleic acid %, nonflber bound nitrogen %, ether extract %, neutral detergent fiber %, acid detergent fiber %, acid detergent lignin %, water soluble material %, and acid/pepsin disappearance % were used as independent variables in regression equations. Forage intake and diet in vivo digestibility could not be accurately predicted from any single variable or combination of independent variables. Fecal acid/pepsin disappearance was the independent variable most highly correlated with forage intake (r = .63) and diet in vivo digestibility (r = .33). Diet nitrogen % was highly correlated with fecal nitrogen % (r = .81) and fecal acid pepsin disappearance % (r = .83). Combined data from this and other studies give a generalized regression equation that shows potential for detecting nitrogen deficiencies in steer diets from fecal N % (organic matter basis) when steer diets contain low levels of soluble phenolics. When steer fecal nitrogen % drops below 1.7%, dietary nitrogen deficiencies should be
Journal of Range Management | 1992
Dave Arthun; Jerry L. Holechek; Joe D. Wallace; M. L. Galyean; Manuel Cardenas; S. Rafique
Two experiments with steers were conducted to evaluate the influence of native forbs and shrubs on nitrogen utilization by cattle. Diets in Exp. 1 were blue grams (Bouteloua gracilis [H.B.K.])(BG), BG plus 23% alfalfa (Medicago sativa) hay (ALF), BG plus 42% forbs and BG plus 41% shrubs. Diets in Exp. 2 included barley (Hordeum vulgare L.) straw, and straw plus either 42% ALF, 63% forbs, or 62% shrubs. Forbs used in our study were scarlet globemallow (Sphaeralcea coccinea Nutt.) and leatherleaf croton (Croton pottsii Lam.). Shrubs included fourwing saltbush (Atriplex canescens [Pursh.]) and mountain mahogany (Cercocarpus montanus Raf.) Forb and shrub mixtures were 50:50 of each species. Blue grams and straw basal diets contained 7.6 and 3.5% CP, respectively. Diets containing ALF, forbs, and shrubs were isonitrogenous (10.5% CP) in both experiments. In Exp. 1, no differences (P>.10) were observed among treatments for N retention (g/d). In Exp. 2, N retention was least (P .05), and intermediate for the forb diet. Inclusion of forbs or shrubs with low-quality forage diets was, in most instances, comparable to inclusion of ALF. Our results indicate that maintaining palatable forbs and shrubs on rangelands should reduce the need to supply cattle with protein during periods when grasses are dormant.
Journal of Range Management | 1990
A. Boutouba; Jerry L. Holechek; M. L. Galyean; Gregorio Nunez-Hernandez; Joe D. Wallace; Manuel Cardenas
In vivo digestibility trfnls were conducted in metrbolism stalls at New Mexico State University to evaluate the influence of leaves of true mountain mahogany (Cercocurpus montanus Raf.) and fourwing saltbush (A tr@w cunescens [Pursh.] Nutt.) on nitrogen retention and digestibility hy Angora goats. Each of the 2 shrubs were fed at 3% and 6% (air dry basis) of the diet along with prairie hay that was comprised mostly of blue grama (Bouteloua grucilis [H.B.K.] Lag. Ex. Griffhhs). High and low shrub diets contained about 12% and 8% crude protein, respectively. Nitrogen retention did not differ (IQO.05) among mountain mahogany and fourwing saltbush diets; however, goats fed the 60% shrub level had greater (P<O.OS)nitrogen retention than did those fed the 3% level. Mountain mahogany diets had a greater soluble phenolic/tannin content than fourwing saltbush diets, but this did not appear to influence nitrogen retention. Forage organic matter intakes averaged 2.% of body weight and did not differ (890.05) among the 4 treatments. Total fecal output of nitrogen (g/d) was highly correlated (1-2 = .71, n = 15) with nitrogen retention. Hence, total fecal nitrogen output may be useful as an indicator of grasing ruminant protein status. Digestible protein (70) and dietary crude protein concentrations were associated poorly with nitrogen retention in our study. Blood serum analysis showed no toxicosis problem for any of the 4 dietary treatments. We concluded that leaves from fourwing saltbush and true mountain mahogany have potential to he an effective source of protein for range livestock consuming low-quality grasses.
Journal of Range Management | 1993
Alipayou Daniel; Jerry L. Holechek; Raul Valdez; Ackim Tembo; Lewis Saiwana; Michael Fusco; Manuel Cardenas
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.
Journal of Range Management | 1992
Gregoria Nunez-Hernandez; Jerry L. Holechek; David Arthun; Ackim Tembo; Joe D. Wallace; M. L. Galyean; Manuel Cardenas; Raul Valdez
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 balance 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.
Journal of Range Management | 1987
Mark D. Hakkila; Jerry L. Holechek; Joe D. Wallace; Dean M. Anderson; Manuel Cardenas
C8ttlc production on desert gmssl8nd nnges in southern New Mexico b8s been low, altbougb lbnited nsnrcb sbows diet nutrition8l qu8llty of cattle is l dqu8te to meet production needs dtig most se8sons. Forrrge intake drt8 8re l8cLing for cattle on desert gmssl8nd rrmges. Five esopb8ge8Histul8ted steers were used to ev8bute diet qtulity urd bot8nierl composition on desert grssI8nd mnge in southern New Mexico. Anotber 6 steers were used to collect feces to determine intake. Cattle cb8nged their diet with se8son8l8dv8nce to nuximize diet quality. Crude protein concentmtions of cattle diets were well 8bove those needed for l8ct8tion 8nd d8ily g8in during spring 8nd summer. Diet samples were bigb in neutr81 detergent fiber (668196), suggesting low energy in the forage. Low fonp intake ~8s the nmin nutrition81 cons-t identified. Even during tbe summer growing season, org8nic nutter int8ke never exceeded 1.5% of body weigbt. We specul8te low int8kes m8y b8ve resulted from bigb summer tempentures tb8t reduced glrxing time. During tbe l8te f8ll md winter, low forrge qu8lity 8ppe8rs to explain suppressed int8ke. Protein supplement8tion in l8te f8ll8nd winter, 8nd energy supplement8tion in spring, sbouid be 8dv8nt8geous. We c8ution tbrt d8t8 on diet qu8lity without infornmtion on folrge intake mry poorly describe nutrition8l st8tus of r8nge c8ttle.
Southwestern Naturalist | 2002
Ricardo Mata-Gonzalez; Rex D. Pieper; Manuel Cardenas
Studies of vegetation patterns on small desert mountains have rarely been conduct- ed. The purpose of this study was to evaluate the influence of aspect and elevation on vegetation of Mt. Summerford, a small desert mountain characteristic of the Basin and Range Province of southwestern United States and northern Mexico. Vegetation was randomly sampled on 4 aspects and 3 elevations (0-80 m, 80-160 m, and 160-240 m) of the mountain. South (S) and west (W) aspects had lower grass cover and higher shrub density than east (E) and north (N) aspects. Grass cover decreased as elevation increased on E and N exposures. In contrast, grass cover increased as elevation increased on S and W exposures. A high density of succulent species was found on lower elevations of the S and W aspects. The most frequent species on the mountain were Bouteloua curtipendula, Bouteloua eriopoda, Muhlenbergia porteri, Aristida ternipes, Aloysia wrightii, Ericameria lari- cifolia, Gutierrezia sarothrae, Fouquieria splendens, Dasylirion wheeleri, and Opuntia. Composition of these species, as a mosaic unit, was significantly different among the aspect-elevation units. Species richness was higher in S and W than in E and N aspects. Differences in vegetation patterns were attributed to differential water and nutrient availability on aspects and elevations. This study sug- gests that topographical change is responsible for vegetation patterns in mountains less than 500 m high.