@proceedings {JRN55416, title = {Assessing grazing behavior of heritage, hybrid, and conventional cattle breeds in response to climate change}, year = {2022}, abstract = {Evidence suggests that heritage and hybrid beef cattle breeds exhibit more flexible foraging behaviors compared to highly selected conventional breeds. We hypothesize that these behaviors could be capitalized upon to support sustainability outcomes, such as biodiversity or climate change adaptation. We conducted a systematic search of studies that compared beef cattle breeds for behavioral traits and found 54 studies conducted since 1966 located in 9 of the 14 major terrestrial biomes, with 60 beef or dual-purpose breeds represented. We created a typology of the studies with respect to decade, continent, breed provenance (Continental, Criollo, Hybrid, B. indicus, Mediterranean, Sanga, British Isles), breed selection intensity (heritage [limited selection pressure], conventional [high selection pressure], hybrid [moderate selection pressure]), biome, study intent, and whether breeds met desired outcomes described by the study authors. Most studies (69\%) were conducted in arid rangeland settings in developed nations where researchers sought to minimize the negative environmental impacts of beef production. In comparisons of grazing behavior of heritage versus conventional types (n=25 studies), and hybrid versus conventional types (n=18 studies), heritage and hybrid cattle displayed more adapted traits (e.g., improved foraging distribution) in 88\% and 78\% of the studies, respectively. No differences were found in grazing behaviors in most studies in which heritage breeds were compared to other heritage breeds or conventional with conventional breeds (n=6 and 15 studies, respectively). In the subset of studies coded with the intent of {\textquotedblleft}foraging behavior,{\textquotedblright} heritage types traveled faster across a range of pasture sizes, which could indicate a capacity to seek high-quality nutrients while reducing trampling or overgrazing. Overall, our review suggests that breeds that have undergone moderate {\textendash} low selection pressure display grazing behaviors that demonstrate adaptation to their respective native environments and may help producers meet production goals in similar environments in the face of a changing climate.}, keywords = {behavior, cattle breeds, climate change, grazing, Heritage cattle, hybrid cattle}, author = {Matthew M. McIntosh and S. Spiegal and McIntosh, S. and Castano Sanchez, Jose and Richard E. Estell and Caitriana Steele and Emile H. Elias and C. Donovan Bailey and Joel R. Brown and Andr{\'e}s F. Cibils} } @proceedings {JRN55360, title = {Explorations of heritage vs conventional cattle in a changing climate}, year = {2022}, month = {2/8/2022}, abstract = {Multiple lines of evidence suggest that heritage Raramuri Criollo (RC) cattle, a biotype with over 400 years of naturalization in the harsh landscapes of the Mexican Copper Canyon, could offer producers a novel means of meeting sustainability and production goals on southwestern rangelands in the face of a rapidly dwindling forage supply and a hotter, drier climate. Compared to conventional breeds (e.g. Angus), RC cows and steers have been documented traveling farther per day and exploring larger areas over multiple seasons, ecosystems (Chihuahuan Desert, California chaparral, and Colorado Plateau), and physiological states. Likewise, RC cows have a lighter body weight and tend toward more even grazing distribution and fewer re-visitation rates during critical periods of the year when rangelands are most vulnerable to overgrazing - suggesting a potentially lighter footprint on soils and vegetation. Raramuri Criollo cows, compared to conventional counterparts, express a unique {\textquotedblleft}follower{\textquotedblright} mothering style, which allows cows more freedom for daily exploration. Rararmuri Criollo also tend to exhibit better heat tolerance by maintaining/regulating internal temperatures, possibly because of body size, hair length, hide color, and behavioral tendencies. Use of RC genetics may present production opportunities related to reduced supplemental feed inputs and potentially lower overhead costs compared to conventional counterparts, while still producing marketable crossbred calves that wean and finish at saleable weights with acceptable carcass traits. This assemblage of studies suggests that RC genetics could be well suited to emerging climate change driven conditions on southwestern ranches because of their unique foraging behaviors and physiology, different resource requirements, and theoretical ability to produce more pounds of weaned beef per pound of cow vs conventional biotypes. Future work will seek to determine what role RC cattle might serve in mitigating climate change impacts and how they could fit into niche and conventional beef production systems. }, keywords = {cattle, changing climate, explorations, heritage vs conventional}, author = {Matthew M. McIntosh and Macon, L. and Matthew Redd and Andr{\'e}s F. Cibils and Richard E. Estell and S. Nyamuryekung{\textquoteright}e and S. A. Utsumi and Amy L. Gonzalez and Andrew Cox and G. Duff and Schallner, J. and S. Spiegal} } @proceedings {JRN55417, title = {Long-term effects of stocking rate, year, and weather on honey mesquite canopy cover and density}, year = {2022}, abstract = {Abiotic (precipitation, temperature) and biotic (grazing) factors are thought to be important drivers of undesirable woody shrub encroachment in arid rangelands. Woody encroachment has pervaded global rangelands over the past century, but the relative impacts of either grazing or climate are still not fully understood. We sought to evaluate the long-term (25 years; 1995-2019) effects of stocking rate (light: 25-30\% and conservative: 35-40\%; key forage species use rate), year, and the interaction of stocking rate by year to explore the impacts of grazing and annual weather fluctuations on percent cover and density of honey mesquite (Prosopis glandulosa), a native but invasive shrub, at the Chihuahuan Desert Rangeland Research Center (CDRRC) in southern New Mexico. Precipitation data were collected continuously at the CDRRC; temperature data were collected at the neighboring USDA-ARS Jornada Experimental Range. Drought occurred in 12 of 25 study years and mean ambient summer temperature increased from 15.1 {\textpm} 0.15 to 15.4 {\textpm} 0.27{\textdegree}C between the first and last 12 years of the study period. We found that stocking rate and the interaction of stocking rate by year had no effect on mesquite percent cover or density (\% cover: P = 0.70; density: P = 0.10), although year had a significant effect (\% cover: P < 0.01; density: P < 0.01). Mesquite canopy cover increased by 3\% from 3.8 to 7.1\% cover and mesquite density increased by 175\% (P < 0.01) from 284 {\textpm} 53 plants*ha to 782.08 {\textpm} 35 plants*ha between the last vs first three years of the study. Our preliminary results support a growing body of literature that suggests the overriding effects of climate (increased temperatures and prolonged droughts) will continue to drive undesirable shrub encroachment on Chihuahuan Desert rangelands even when animal stocking rates are kept at historically sustainable levels.}, keywords = {and density, canopy cover, honey mesquite, Long-term effects, stocking rate, weather, year}, author = {Matthew M. McIntosh and Jerry L. Holechek and S. Spiegal and Andr{\'e}s F. Cibils and Richard E. Estell and Caitriana Steele and Jeon, S. and Brandon T Bestelmeyer} } @proceedings {JRN55365, title = {Precision grazing: State of the science and opportunity for user feedback on new technologies}, year = {2022}, month = {3/29/2028}, abstract = {Precision farming technologies are an emerging management platform aimed at digitizing crop and animal production practices to enable detection and mediation of real-time environmental and welfare concerns and to equip producers with affordable, accurate, and easy-to-use tools to improve production sustainability. The goal of this symposium is to highlight current state-of-the-art precision grazing and digital ranching tools, techniques, and platforms under study and in development for application on extensive rangelands. The session will be broadly targeted toward scientists, government agencies, and producers, all of whom are presumed to benefit from precision grazing technologies. The morning session of the Precision Grazing symposium will feature a suite of rangeland scientists investigating various precision grazing tools including virtual fencing, tri-axial accelerometers, and grazing detection instruments, as well as producer outlooks on digital ranching necessities. The afternoon session will feature work conducted by the Sustainable Southwest Beef Coordinated Agricultural Project which is aimed at developing an integrated precision grazing system and dashboard that can track cattle and sheep welfare and geolocation, body condition scores, and other ranch infrastructure in near real time in various production systems.}, keywords = {feedback, new technologies, opportunity, Precision grazing, science, state}, author = {Matthew M. McIntosh and S. Spiegal and Skye Aney and Jean Steiner} } @conference {JRN55355, title = {Testing of a LoRa-WAN digital ranching system on desert rangelands: Some practical experiences}, booktitle = {2021 NMSU ACES BEEF, DAIRY AND LIVESTOCK UPDATE Presented by NMSU Cooperative Extension Service}, year = {2022}, month = {1/25/2022}, abstract = {Precision livestock farming (PLF) is an emerging agricultural strategy that incorporates sensors and data analytics to inform management decisions (Neethirajan, 2017; Tedeschi et al., 2021). Though common in household and more intensive livestock and crop production systems, Internet of Things (IoT) tools are in earliest stages of development for extensive beef and sheep production systems on arid rangeland primarily due to limited infrastructure and lack of Wi-Fi, cellular (e.g. 3 and 4G), or satellite network access. Yet Long Range Wide Area Networks (Lora-WAN) could offer a high efficiency and low-cost solution to this hindrance as they promise near-real time long-range coverage (e.g. > 6 mi), a strong signal, long battery life, and customizable data collection units (e.g. widgets or sensors), compared to other conventional network types (Bocquier et al., 2014). Precision livestock technologies could provide New Mexican livestock producers novel tools for realtime monitoring of animal location and activity, asset tracking, and infrastructure monitoring in the face of a dwindling workforce and harsher climate (Spiegal et al., 2020). This study aimed to test a PLF LoRa-WAN-based monitoring system across four pastures (12,000 ac) of Chihuahuan Desert rangeland. We report the installation protocol, maintenance, and practical applications associated with the system.}, keywords = {beef cattle, digital agriculture, GPS-tracking, Precision grazing, Precision livestock farming, rain gauge sensor, water level sensor}, url = {files/bibliography/21-059.pdf}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and S. Nyamuryekung{\textquoteright}e and Richard E. Estell and Andrew Cox and Danielle Duni and S. A. Utsumi and Qixu Gong and Tony Waterhouse and J P Holland and Huiping Cao and LE Boucheron and H. Chen and S. Spiegal} } @article {JRN55342, title = {Can cattle geolocation data yield behavior-based criteria to inform precision grazing systems on rangeland?}, journal = {Livestock Science}, volume = {255}, year = {2021}, month = {12/5/2021}, pages = {104801}, abstract = {A key challenge of precision grazing systems is identifying behavior anomalies associated with situations of reduced animal production and wellbeing. We determined typical ranges of diel variation of movement and activity patterns of steers on rangeland to identify metrics that could serve as sensitive indicators of behavior anomalies. Seventeen Raramuri Criollo or Criollo crossbred yearling steers weighing 318 {\textpm} 9.3 kg (winter; W) or 358 {\textpm} 8.4 kg (late summer; LS) were fitted with GPS collars that recorded animal location at 5-min intervals. Steers grazed a 3,215-ha rangeland pasture for approximately 67 d in W or LS of 2016 and 2017. GPS data were used to derive 22 commonly monitored behavior variables. Means and day-to-day variation (CV\%) of all behavior metrics were calculated for each animal as well as linear correlations between the CV of each behavior and ADG. Daily time spent resting or grazing exhibited the least day-to-day variation in both W and LS (CV resting =10.8 and 9.9\%, respectively; CV grazing =13.8 and 14.8\%, respectively); predawn area explored (CV =240.8\%) and time spent at drinkers (CV =336.6\%) exhibited the most daily variation in W and LS, respectively. During W, increasing day-to-day variation in daytime distance traveled and area explored, as well as daily time spent traveling were associated with increasing ADG (r = 0.56 to 0.58; P < 0.05). In LS, steers with greater CV for 24-h area explored, time spent traveling, or daytime distance traveled tended to gain less weight (r =-0.77 to -0.84; P < 0.01), while steers with more flexible 24 hour path sinuosity tended to gain more weight (r = 0.93; P < 0.01). Behavior metrics more closely associated with forage intake processes, such as daily time spent grazing or resting, exhibited lowest diel variation levels and could be used to diagnose non-normal behavior of cattle on rangeland.}, keywords = {Average daily weight gain, beef cattle, GPS monitoring, Precision grazing, Precision livestock ranching}, doi = {10.1016/j.livsci.2021.104801}, url = {files/bibliography/21-053.pdf}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and Richard E. Estell and Qixu Gong and Huiping Cao and Amy L. Gonzalez and S. Nyamuryekung{\textquoteright}e and S. Spiegal} } @conference {JRN55340, title = {Conventional vs Heritage cattle supplement intake, weight-gains, and body condition scores on Chihuahuan desert pasture}, year = {2021}, month = {10/08/2021}, abstract = {Use of adapted beef cattle biotypes is gaining momentum as a novel management strategy for limiting the environmental footprint of ranching and adapting to climate change in the southwest. We compared supplement intake (SI), calf birthweights, cow weights, and body condition scores (BCS) of desert-adapted Brangus (BR; n = 15) vs. Raramuri Criollo (RC; n = 28) cows in four adjacent pastures (1098{\textpm}85 ha) for three months (Mar 7 {\textendash} Jun 9, 2020) using ANOVA for a RCBD (significance at P < 0.05). Cows had ad libitum access to 18\% crude protein lick tubs in all pastures, which were weighed weekly to determine SI. Brangus cows had greater SI than RC, both overall (BR: 0.21{\textpm}0.04 vs. RC: 0.08{\textpm}0.03 kg{\texttimes}cow{\texttimes}d-1) and on a metabolic bodyweight basis (BR: 2.31{\textpm}0.09 vs. RC: 0.95{\textpm}0.09 g{\texttimes}kg0.75). All cows were bred to Brangus bulls and calf birth weights were not different between biotypes (BR: 31.5 {\textpm} 1.0; RC: 29.6{\textpm}0.9 kg). Brangus cows weighed more at the beginning (535.0{\textpm}14.8 kg) and end (582.2{\textpm}14.5 kg) of the study compared to RC (beginning: 345.5{\textpm}11.8 kg; end: 357.0{\textpm}12.0 kg). Percent of bodyweight change was not different between biotypes (BR: 8.51{\textpm}2.35; RC: 2.85{\textpm}1.81 \%). On a 1 to 5 scale, BCS of Brangus (4.06{\textpm}0.09) was greater than RC (3.18 {\textpm} 0.07) at the onset of the study, but biotypes had similar BCS at the end of the trial (BR: 4.09 {\textpm} 0.09; RC: 3.89{\textpm}0.08). Our preliminary results indicate that lighter RC cows were capable of gaining bodyweight and improving BCS with reduced SI, both overall and on a metabolic bodyweight basis. This finding may reflect lower nutrient requirements, better relative efficiencies and lesser grazing impacts on desert rangelands by RC cattle. Future studies will seek to replicate these breed-comparison trials over multiple years, research sites, and supply chains, with an emphasis on overall systems production efficiency and sustainability.}, keywords = {body condition scores, Chihuahuan desert pasture, Conventional vs Heritage cattle, supplement intake, weight- gains}, doi = {10.1093/jas/skab235.687}, url = {files/bibliography/21-051.pdf}, author = {Matthew M. McIntosh and Richard E. Estell and Andr{\'e}s F. Cibils and Andrew Cox and S. Nyamuryekung{\textquoteright}e and Danielle Duni and G. Duff and S. Spiegal and Carolina Brandani and S. A. Utsumi and V. Gouvea} } @conference {JRN55303, title = {Long-term declining trends in Chihuahuan Desert forage production in relation to stocking rates and climate}, booktitle = {Society for Range Management Meeting Abstracts}, year = {2021}, month = {02/15/2021}, abstract = {We analyzed a 25-yr time series (1995 {\textendash} 2019) of stocking rate (SR), ambient temperature, precipitation, and perennial grass production (PGP) at a 4000-ha site in the Chihuahuan Desert. Using the Proc Glimmix procedure in SAS 9.4, we analyzed effects of two SRs (light: 25-30\% vs conservative: 31-40\% forage use rate), year, and SR {\texttimes} year to evaluate time trends. Stocking rates had no effect on PGP (P~= 0.25), but year did (P~< 0.01). Stocking rate {\texttimes} year did not affect PGP (P~= 0.94). We found a 75\% reduction in in kg * ha-1~PGP when the first (115.4 {\textpm} 18.7 kg DM perennial grass) vs last three (28.27 {\textpm} 18.67 kg DM perennial grass) study years periods were compared (P~< 0.01). Annual average ambient temperature during the 25-y study increased by more than 1{\textdegree}C (beginning: 15.22 {\textpm} 0.2 vs end: 16.7 {\textpm} 0.2{\textdegree}C). Mean maximum June temperature (P~< 0.01;~r~= - 0.39) was negatively associated with PGP. Conversely, PGP was positively associated with total annual precipitation (P~< 0.01; r = 0.28). The interaction of June mean maximum temperature and annual precipitation negatively affected PGP (P~< 0.01). These preliminary results suggest that climate may have an overriding effect on Chihuahuan Desert forage production even when appropriate stocking rates are applied. Sustainability of beef production systems on southwest rangeland will increasingly be hampered by forage yields less than 100 lb*ac-1; the point at which point livestock grazing becomes financially unsound.}, author = {Matthew M. McIntosh and Jerry L. Holechek and Andr{\'e}s F. Cibils and Richard E. Estell and S. Spiegal} } @article {JRN55286, title = {Weight gain, grazing behavior and carcass quality of desert grass-fed Rar{\'a}muri Criollo vs. crossbred steers}, journal = {Livestock Science}, volume = {249}, year = {2021}, month = {10 April 2021}, abstract = {Rar{\'a}muri Criollo cattle producers often crossbreed their cows with improved beef-breed bulls and/or retain and develop their yearlings on rangeland because of limited weaned calf markets, however it is unknown if Rar{\'a}muri Criollo steers exhibit marketable weight gains and carcass qualities, or desirable grazing behaviors documented in cows of this biotype. We evaluated two cohorts (cohort: 1 = 31, 2 = 26) of Rar{\'a}muri Criollo (JRC), Mexican Criollo (MC) and Criollo {\texttimes} beef-breed crossbred (XC) steers to investigate effects of biotype on growth, carcass traits, and landscape utilization. Steers were weighed approximately once every 2-mo and average daily gains (ADG) calculated. Nine JRC and XC steers per cohort were monitored at 5-min intervals via global positioning systems (GPS) for 1-mo during winter (2015{\textendash}16) and late-summer (2016{\textendash}17). Weight and carcass data were analyzed using mixed measures procedures to identify differences between biotype through time. Discriminant analyses were conducted to determine whether grazing behaviors could be discriminated among: 1) JRC and XC steers and JRC cows; 2) steers by season (winter vs. summer); and 3) steers of cohort 1 and 2. Final live and carcass weights of XC were greater than JRC and MC, but all were market ready at 30-mo following a grass-finishing protocol. Carcass quality and ADG were not different among biotypes. Steers were discriminated into different season or cohort groups based on grazing behavior differences but JRC and XC steers exhibited grazing patterns that were similar to those previously observed in JRC cows. Our results suggest that JRC, MC, and XC steers can be developed to slaughter weights in 30-mo using a rangeland-based grass-fed protocol, and that JRC and XC steers exhibit desirable grazing behaviors previously observed in JRC cows.}, keywords = {beef cattle, climate change, Grass finished steers, Grass-fed supply-chain, Heritage genetics, livestock behavior}, issn = {1871-1413}, doi = {10.1016/j.livsci.2021.104511}, url = {files/bibliography/21-020.pdf}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and Richard E. Estell and S. Nyamuryekung{\textquoteright}e and Amy L. Gonzalez and Qixu Gong and Huiping Cao and S. Spiegal and S. Soto-Navarro and Amanda D.Blair} } @article {JRN55267, title = {A phenotypic characterization of Rar{\'a}muri Criollo cattle introduced into the southwestern United States}, journal = {Archivos Latinoamericanos De Produccion Animal}, volume = {28}, year = {2020}, month = {11/5/2020}, pages = {111-119}, abstract = {Our objective was to describe key phenotypic characteristics of a population of Rar{\'a}muri Criollo (RC) cattle introduced from the Copper Canyon of Chihuahua, M{\'e}xico into the Southwestern United States almost two decades ago. We recorded 26 phenotypic traits of 37 RC individuals including mature cows, first--calf heifers, and mature bulls raised at the USDA--ARS Jornada Experimental Range in southern New Mexico. This herd of RC cattle exhibited intermediate body sizes (390 kg) compared to the smaller Corriente (300 kg) and larger Texas Longhorn (400 kg) and Florida Cracker cattle (400 kg). Coat colors were similar to those described for other Criollo biotypes but horn shape and size of RC appear to be different than that of other US--based Criollo breeds. Though smaller than commercial beef breeds, RC cattle appear to be well -matched to the Southwestern US environments as evidenced by previous studies that evaluated their grazing behavior, weight gains, and carcass quality. Rar{\'a}muri Criollo cattle are a genetic resource whose conservation could be critically important for climate change adaptation of ranches in the desert Southwest. https://ojs.alpa.uy/index.php/ojs_files/article/view/2832}, keywords = {beef cattle, climate change, genetic conservation, heritage breed}, url = {files/bibliography/21-003.pdf}, author = {Matthew M. McIntosh and Amy L. Gonzalez and Andr{\'e}s F. Cibils and Richard E. Estell and S. Nyamuryekung{\textquoteright}e and A.F.A. Rodriguez and S. Spiegal} } @conference {JRN55143, title = {Carcass characteristics of Criollo and Criollo crossbred steers raised on Chihuahuan Desert rangeland}, booktitle = {2019 ASAS-CSAS Annual Meeting and Trade Show}, year = {2019}, month = {07/10/2019}, publisher = {American Society of Animal Science (ASAS-CSAS)}, organization = {American Society of Animal Science (ASAS-CSAS)}, address = {Austin, TX}, abstract = {

We compared carcass characteristics of 11 Raramuri Criollo (RC) and 8 Criollo x Brangus crossbred (XC) steers raised together on Chihuahuan Desert rangeland. Steers entered the trial (completely randomized design) at approximately 5 months of age (December, 2015). Initial weights of RC and XC steers were 233.7 {\textpm} 7.8 and 231.4 {\textpm} 9.2 kg, respectively. Steers weighed 423.1 {\textpm} 7.8 (RC) and 483.0 {\textpm} 9.2 (XC) kg at 29 months of age (February 1, 2018), before being shipped to South Dakota where they were fed hay for approximately one month until slaughter (February 28, 2018). Carcass characteristics, such as hot (HCW) and cold carcass weights (CCW), preliminary yield grade (PYG), ribeye area (REA), marbling score (MS), and quality grade (QG) were assessed. Breed effects for all variables (excluding QG) were analyzed using SAS Proc Mixed; SAS Proc Npar1way was used to evaluate QG. Compared to XC, RC steers had lighter (P \< 0.01) HCW (220 {\textpm} 5 vs. 265 {\textpm} 6 kg) and CCW (210 {\textpm} 5 vs. 254 {\textpm} 6 kg), and smaller (P \< 0.01) REA (56 {\textpm} 1.4 vs. 61.7 {\textpm} 1.6 cm2). No differences (P \> 0.05) were observed between RC and XC steers in PYG (2.3 {\textpm} 0 vs. 2.4 {\textpm} 0.2) or MS (452 {\textpm} 31 vs. 456 {\textpm} 36). Average QG for all carcasses was between high standard and low choice and was not different (P \> 0.05) for RC versus XC carcasses. Our preliminary results show no major difference in carcass quality parameters of RC and XC steers developed on Chihuahuan Desert rangeland.

}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and Richard E. Estell and Amy L. Gonzalez and S. Spiegal and Blair, A. and S. Nyamuryekung{\textquoteright}e and S. Soto-Navarro and C. Tolle} } @article {JRN55158, title = {Long-term declining trends in Chihuahuan Desert forage production in relation to precipitation and ambient temperature}, journal = {Rangeland Ecology and Management}, volume = {72}, year = {2019}, month = {11/01/2019}, abstract = {

Rising temperatures and more frequent droughts are posing new challenges to range livestock producers in the southwestern United States and many other parts of the world. We analyzed a 49-year time series (1969-2017) of precipitation, ambient temperature, and perennial grass production (PGP) as well as 14 years (2001-2014) of MODIS-derived vegetation phenometrics at a site in the Chihuahuan Desert of New Mexico. PGP was positively associated with December through September precipitation (r = 0.74; P \< 0.05) but negatively associated
with spring and summer (Mar-Sep) maximum average ambient temperature (r = -0.54; P \< 0.05). PGP decreased by 38\% in the second (1994-2017) compared to first half (1969-1993) of our study (228 \± 36.75 vs. 141 \± 21.97 kg DM*ha-144 ; P \< 0.01). Precipitation was lower and more erratic in the second half of the time series decreasing by 21\% (264.88 \± 1.30 vs. 211.13 \± 16.67 mm; P = 0.01). Conversely, mean maximum and mean ambient temperatures were higher during the 1994-2017 period (max T: 24.48 \± 0.14 vs. 25.22 \± 0.13\°C; P \< 0.01; mean T:14.45 \± 0.13 vs. 15.04 \± 0.13\°C; P \< 0.01). MODIS-derived NDVI analysis showed that growing seasons began and ended later and became shorter (P \< 0.05) over the 14 years analyzed. During this period, increasing maximum summer (Jun-Sep) ambient temperatures were associated with decreasing growing season NDVI values (P \< 0.01). Over the 49-year study period, Chihuahuan Desert rangelands at our research site lost 38\% of grazing capacity. Nine drought years occurred in the second half of our study compared to two in the first half. Our research supports predictions by climate scientists that more frequent droughts and lower as well as more erratic precipitation will adversely impact grazing capacity of rangelands in the southwestern United States.

}, keywords = {climate change, forage, grazing capacity, NDVI, phenometrics}, doi = {10.1016/j.rama.2019.06.002}, url = {files/bibliography/19-025.pdf}, author = {Matthew M. McIntosh and Jerry L. Holechek and S. Spiegal and Andr{\'e}s F. Cibils and Richard E. Estell} } @conference {JRN54995, title = {Long-term Trends in Perennial Grass Production, Precipitation and Temperature in the Chihuahuan Desert}, booktitle = {72nd Society for Range Management International Meeting}, year = {2019}, month = {02/2019}, publisher = {Society for Range Management Meeting Abstracts}, organization = {Society for Range Management Meeting Abstracts}, address = {Minneapolis, Minnesota}, abstract = {

Rising temperatures and more frequent droughts are posing new challenges to livestock producers in the Southwest. Our objective was to evaluate long-term perennial grass production (PGP) in the Chihuahuan Desert in relation to ambient temperature and precipitation. PGP was correlated with precipitation (mm) and ambient temperature (oC) over a 49-year period (1969 {\textendash} 2017). Increasing precipitation in December through September was associated with higher PGP (r = 0.74, n = 49) whereas rising maximum average temperatures in March through September were associated with a reduction in PGP (r = -0.54, n = 49). Two-sample t-tests comparing averages of each variable for the first and last 25 years of the study period (1969-1993 vs. 1994-2017) revealed that mean PGP decreased by 35\% (220.7 {\textpm} 12.5 vs. 143.92 {\textpm} 15.89 kg DM*ha-1; P \< 0.01), precipitation was more variable and decreased by 21\% (264.88 {\textpm} 1.30 vs. 211.13 {\textpm} 16.67 mm; P = 0.01), whereas mean maximum temperature (24.48 {\textpm} 0.14 vs. 25.22 {\textpm} 0.13{\textdegree}C; P \< 0.01) and mean temperature (14.45 {\textpm} 0.13 vs. 15.04 {\textpm} 0.13{\textdegree}C; P \< 0.01) increased by\  0.7oC and 0.6o C, respectively. Over this 49-year period, Chihuahuan Desert rangelands at our research site lost 35\% of grazing capacity (approximately 84 AUMs/1000 ha [7 AUYs/1000 ha]). Our research shows that increased temperatures and more frequent droughts are severely impacting forage and range livestock production in the southwest.

}, author = {Matthew M. McIntosh and Jerry L. Holechek and Andr{\'e}s F. Cibils and Richard E. Estell} } @proceedings {JRN54869, title = {Weight gain and behavior of Raramuri Criollo versus Corriente steers developed on Chihuahuan Desert rangeland}, volume = {January 28-February 2, 2018}, year = {2018}, month = {01/28/2018}, publisher = {Society for Range Management Meeting Proceedings}, address = {Sparks, Nevada}, abstract = {

Ranchers that raise Criollo cattle must overcome the challenge of lack of markets for weaned calves. Raramuri Criollo (RC) steers are commonly raised for beef and finished on rangelands, while Corriente (CR) are often raised for rodeo sports. No data exist on weight gains and grazing behavior of rangeland-raised steers of either biotype. We conducted a study in the Chihuahuan Desert with two cohorts of RC and CR. Twenty-two 17-month (cohort 1) steers (10 RC, RC1; 12 CR, CR1) were weighed every 60 d between December 2015 and January 2017 and eighteen 8-month (cohort 2) steers (7 RC, RC2 and 11 CR, CR2) were weighed every 60 d between December 2015 and August 2017 to determine individual body weight (WT), average daily gain (ADG), and body condition score (BCS). 9 cohort 1 steers and 9 cohort 2 steers were monitored with Lotek 3300LR GPS collars that recorded location at 5 min intervals during December 2015 and December 2016, respectively, to compare landscape utilization patterns of 5 RC and 4 CR individuals. The influence of biotype on WT, ADG, BCS and behavior variables was analyzed using repeated measures mixed ANOVA that treated steers as the experimental unit. Separate analyses were conducted per age cohort. No differences in WT, ADG, or BCS between RC and CR in either cohort were detected throughout. RC1, CR1, RC2, and CR2 gained on average 0.2036, 0.1420, 0.1881, and 0.2419 kg/head/d, respectively. Daily distance traveled by RC1 and CR1 did not differ, but CR2 walked farther during day and night than RC2 (P \<0.01). CR1 followed more sinuous trajectories than RC1 counterparts from dusk to midnight (P\<0.01). CR2 followed more sinuous movement trajectories than RC2 at night (P\<0.01). \ Further research is needed to determine the benefits of developing RC vs CR steers on desert rangeland.

}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and Richard E. Estell and S. Soto-Navarro and Amy L. Gonzalez and S. Nyamuryekung{\textquoteright}e and S. Spiegal} } @conference {JRN54670, title = {Weight gain and behavior of Raramuri Criollo versus crossbred steers developed on Chihuahuan Desert rangeland}, booktitle = {70th Annual Society for Range Management Meeting}, volume = {Jan. 29 - Feb. 2, 2017}, year = {2017}, month = {01/2017}, publisher = {Society for Range Management}, organization = {Society for Range Management}, address = {Saint George, Utah}, abstract = {

Ranchers that raise Raramuri Criollo (RC) cattle must overcome the challenge of lack of markets for weaned calves. \ Growing and finishing RC or RC-crossbred steers on rangeland pastures is increasingly common; however, no data exist on their weight gains or grazing behavior. \ We tracked the weight and behavior of four groups of steers in the Chihuahuan Desert to understand the viability of this production approach. Nineteen 8-month steers (eleven RC, RC-8, and eight Brangus{\texttimes}Criollo, BRCR-8) and nineteen 17-month steers (ten RC, RC-17; nine Waguli{\texttimes}Criollo, WACR-17) were weighed every 60 days between 12/2015 and 10/2016 to determine individual body weight (WT), average daily gain (ADG), and body condition score (BCS). In addition, we used Lotek 3300 GPS collars to monitor location (at 5-minute intervals) of five RC-17 and five WACR-17 individuals in 12/2015. \ Influence of breed on WT, ADG, BCS and behavior was analyzed using repeated measures mixed ANOVA treating steers as experimental units. Separate comparisons were conducted within each age group. \ Crossbreds were heavier than their RC counterparts at the beginning of the study and WT differences in both groups persisted throughout (P\<0.01). \ ADG of RC-17 and WACR-17 were not detectably different, however BRCR-8 steers showed higher ADG than their RC-8 counterparts (P \< 0.014). BCS of crossbreds was significantly higher than that of RC steers in both age groups throughout (P\< 0.01). \ Overall, RC-8, BRCR-8, RC-17, and WACR-17 gained on average 158, 203, 166, and 156 lb head-1 11 months-1, respectively. \ Daily distance traveled by WACR-17 and RC-17 did not differ, however WACR-17 walked farther during nighttime hours (P \<0.01) and followed less sinuous movement trajectories (P\<0.01) than their RC-17 counterparts. Although WT gains at a younger age were improved by crossbreeding RC with Brangus, further research is needed to determine performance of older BRCR and younger WACR crossbreeds.

}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and Richard E. Estell and S. Soto-Navarro and Amy L. Gonzalez and S. Nyamuryekung{\textquoteright}e and S. Spiegal} }