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The Southwestern U.S. has experienced frequent drought over the past 30 yr, and wildfire frequency and intensity has been increasing which threatens western rangelands. In the west, livestock grazing systems often involve a combination of private, state, and federal land, and the grazing managers must comply with designated grazing plans. In 2022, the Black Fire in southern NM was the second largest wildfire in state history and burned hundreds of thousands of hectares of rangeland including fencing which impeded the ability to comply with grazing management plans. Local extension agents along with area beef producers and federal grazing managers revealed the largest challenge they faced was lack of fencing and fence damage due to wildfire loss and floods. Labor shortages, replacement costs, and difficult terrain inhibited the ability to replace fences and sufficiently manage cattle. Virtual fencing (VF) technology allows containment of cattle without physical fencing, but the technology has not been evaluated in extensive systems in the SW challenged by large pastures and extremely difficult terrain. NMSU Extension worked with producers and federal grazing managers to evaluate the effectiveness of VF as a response to wildfire. All procedures were approved by NMSU Institutional Animal Use and Care Committee (2211000086). Two large allotments (17,233 and 5,776 ha, respectively) were evaluated for cellular receptivity and LoRa WAN connectivity and 2 peaks per allotment were identified for installation of LoRa WAN receiving stations. Two ranchers enrolled in the program and were trained to VF principles and Vence software platforms. Cows (n = 100/rancher) were trained to Vence VF collars utilizing physical fence in conjunction with sound and electrical pulse. After a 4-d training period, cattle were grazed across 2 to 3 large pastures per site. Containment efficacy was evaluated via GPS position data. In allotment A and B, LoRa WAN packet communication was 46% and 37%, respectively. After 230 d of testing, cattle containment using VF in combination with remaining perimeter fence and terrain barriers was estimated at 79% and 94% for pastures A and B, respectively. Producers reported that GPS location data helped reduce gathering time by 1 to 2 wk and increased gathering efficiency by approximately 10%. Results demonstrated that VF technology can reasonably be used in response to partial fencing loss during post-fire recovery and there is a need for Extension to provide support for new technology utilization on ranching operations. Project was supported by USDA/ NIFA #2023-68016-38885. [ABSTRACT FROM AUTHOR]

Nearly one-half of beef cows in the United States are located in southern states where cow-calf operations predominate. Grazing management in cowcalf systems can be affected by environmental and seasonal conditions, often leading to nutrient deficiency, particularly during late gestation of beef females. Maternal nutrition during the last trimester of gestation can influence offspring development and health, and can be explored to optimize maternal and progeny performance. The objective of this presentation is to share nutritional and management strategies for pregnant beef cows and their long-term effects on offspring growth and physiology. Study 1 investigated the effects of timing of maternal protein supplementation during all last trimester of gestation (LATE84), only the first 42 d of last trimester of gestation (LATE42), or no prepartum supplementation (NOSUP) on offspring pre- and post-weaning performance. At weaning, LATE84 calves were the heaviest, followed by LATE42, and NOSUP (P ≤ 0.05). Steer serum parainfluenza-3 titers were greater (P = 0.03) for LATE42 vs. NOSUP and tended to be greater for LATE84 (P = 0.10) vs. NOSUP steers. Marbling and the proportion of steers grading choice were greater (P ≤ 0.04) for LATE42 vs. NOSUP, and intermediate for LATE84. Study 2 evaluated the effects of frequency of maternal protein supplementation on offspring pre-weaning growth. Cows received the same weekly amount of supplement (7 kg·cow-1·wk-1) but with different frequencies: once a week (1X), three times per week (3X), every day (7X), or no prepartum supplementation (NOSUP) during the last 80 d of gestation. At weaning, calves born from 7X cows were the heaviest (P ≤ 0.05), followed by 3X and 1X, which did not differ between them (P = 0.54), and NOSUP calves were the lightest (P ≤ 0.05). Study 3 evaluated the use of monensin supplementation during the last 77 d of gestation and its impacts on offspring performance. Treatments consisted of no prepartum supplementation (NOSUP), supplementation of dried distillers grains at 1 kg·cow⁻¹·d⁻¹ added with 0 (SUP) or 200 mg/d of monensin (SUPMO). At weaning, SUPMO calves were the heaviest (P ≤ 0.05), SUP intermediate, and NOSUP were the lightest. Experiment 4 consisted of pregnant heifers receiving the supplementation of 1 kg/d of soybean hulls dry matter added (BAC) or not (CON) with a Bacillus-based DFM mixture during late gestation (d 0 to 139) and early lactation (d 139 to 242). Post-weaning body weight gain and indicators of humoral immune response post-vaccination were greater for BAC vs. CON calves (P ≤ 0.05). Therefore, changing the time and frequency of supplementation, and the use of additives and probiotics during late gestation of beef females are effective alternatives to improve offspring pre- and post-weaning growth and immune response. [ABSTRACT FROM AUTHOR]

Western rangelands represent approximately 58% of the total arable land in the U.S. and are used primarily for cow-calf production, which has the largest greenhouse gas (GHG) emission footprint of all beef production phases. Further, beef production sustainability concerns involve climate mitigation (reducing GHG output) and adaptation (climate-resilient soil-plant-animals). Precision livestock farming (PLF) may help address sustainability concerns by providing innovative solutions and new opportunities for extensive rangeland production. The use of precision measurement and management tools with precision system models can connect measurement data to inform management capabilities. For example, real-time individual weighing and remote sensing (precision measurement tools) can be used to inform and implement dynamic rotational grazing management using virtual fencing technology (precision management; Menendez et al., 2022, 2023). Recent USDA investment in climatesmart agriculture (CSA) commodities has provided over $3 billion in funding to implement practices to reduce GHG emissions in agriculture production, for which PLF may be one approach to accomplish these goals. The overall purpose is to develop commodities produced using NRCS climate-smart practices (e.g., prescribed grazing, 528) and document reductions to provide market opportunities associated with inset GHG. Currently, South Dakota State University is leading two simultaneous programs, which include precision ranching (virtual fencing, precision weighing, and GHG evaluation) and a beef and bison CSA program (GHG evaluation; 7 producer-owned research ranches, representing more than 1.09 million ha). The scale of the CSA program has revealed that current PLF research has only been a prelude to providing the precision tools necessary to successfully implement CSA practices and document their impact through monitoring, measuring, reporting, and verification (MMRV). This presentation will include rangeland grazing case studies that cover the application of virtual fencing, animal location, behavior tracking, remote sensing, precision weighing, feeding, supplementation, and enteric emissions and soil moisture monitoring on extensive rangelands. Case studies will include an overview of big data processing and precision system model development methods. Increasing awareness of available PLF tools for optimizing grazing management, animal performance, productivity, and associated challenges (maintenance, costs) is essential for meeting livestock and sustainability goals. PLF and data-driven approaches aid in the creation of scalable, cost-effective MMRV protocols and models (soil carbon and enteric GHG) for extensive rangelands (20 to 70,000 ha areas) that allow producers to realize potential CSA market incentives. Further, MMRV will likely help guide management decisions by identifying CSA strategies that build climate-resilient landscapes for sustainable livestock production and other environmental synergies (soil microbiome, bird and insect habit, water retention). [ABSTRACT FROM AUTHOR]

Our objective was to evaluate how virtual fencing grazing management during the stocker phase influences steer growth performance, carcass traits, and enteric emissions during the finishing phase. Angus steers [n = 96; initial body weight (BW) = 375 ± 7.2 kg) grazed native rangeland from 07 June 2023 to 31 August 2023 in Cottonwood, SD at South Dakota State University’s Cottonwood Field Station. Following summer grazing, steers were transported to Brookings, SD and fed for 130-d at the South Dakota State University Cow-Calf Education and Research Facility. During the summer grazing season, steers were assigned to different stocking rates (Light, Moderate, and Heavy, at 0.32, 0.42, and 0.72 animal unit months, respectively), and grazing strategies [continuous (CG) or virtual fencing rotational (RG)] in a 2 × 3 factorial design. Steers were transitioned from a 30% roughage to a 10% roughage diet over 21-d. The finishing diet (13.7% CP, 17.2% NDF, 1.36 Mcal/kg NEg, and 30 g/907-kg monensin sodium) was manufactured twice daily and provided ad libitum. Feed consumption was tracked using precision monitoring equipment (Insentec, The Hague, Netherlands). Steers were individually weighed on d 1 (entry BW), 21, 63, 90, and 130 and administered a steroidal implant (200 mg trenbolone acetate and 20 mg estradiol; Revalor-200, Merck Animal Health, DeSoto, KS) on d 21. Enteric emissions, including methane and carbon dioxide, were monitored using the GreenFeed trailer system (C-Lock Inc., Rapid City, SD), growth performance, carcass traits, and categorical carcass traits were analyzed in a factorial design using a randomized complete block design with individual steer considered the experimental unit. Final BW was determined from hot carcass weight divided by 0.625. Steers from heavy-CG had greater feedlot entry BW (P ≤ 0.05) compared with all treatments except light-CG and light-RG. Light-CG and light-RG had greater entry BW compared with heavy-RG (P ≤ 0.05). Gain efficiency was greater for light-CG compared with light-RG, moderate-CG, and heavy-CG (P ≤ 0.05), while moderate-RG and heavy-RG were intermediate (P ≤ 0.05). Steers from moderate-RG had greater marbling scores compared with heavy-RG (P = 0.05), and all other treatments were intermediate. Neither stocking density (P ≥ 0.15) nor grazing management strategy (P ≥ 0.13) had any influence on other measures of growth performance, emissions (CH4 and CO2 ) production rate, or carcass traits. These findings suggest that stocking density and grazing-management strategy (CG vs. virtual fencing-RG) influence gains on pasture and alter feedlot entry BW, highlighting the need for further investigation into their implications for greenhouse gas emissions, as well as for determining optimal stocking densities and management strategies for ranchers [ABSTRACT FROM AUTHOR]

Grazing management and N-fertilizer have been reported to improve tropical forage productivity and quality, however, their effect on methane emission of grazing animals remains uncertain. Therefore, this study aimed to assess the effects of increasing application rates of nitrogen (N) fertilization of Marandu palisadegrass under continuous stocking on intake, digestibility, nitrogen balance, and enteric methane emissions of Nellore growing bulls. We hypothesized that changes in the forage nutritive value caused by N fertilization of pastures combined with adequate grazing management (e.g. greater crude protein [ CP ] and digestibility) would lead to an increase in animal productivity (e.g. greater average daily gain [ ADG ] and gain per area), and then, to a decrease in methane emission intensity. Treatments consisted of different annual application rates of nitrogen fertilization: 0, 75, and 150 kg N/ha using ammonium nitrate (32% N) as the nitrogen source. The experimental design was completely randomized, with three treatments and four replications (12 paddocks). Intake, digestibility, N balance, and methane emissions were measured in eight animals per treatment. CP intake, digestibility and N balance increased linearly with the increase in N fertilization (P < 0.05). In addition, stocking rate (SR) and ADG linearly increased from 1.75 animal unit (AU = 450 kg)/ha and 0.62 kg/d (0 kg N/ha) to 3.75 AU/ha and 0.82 kg/d (150 kg N/ha), respectively. Individual methane emissions nor methane emission intensity were affected by treatment with an average of 164.7 g/d and 199.7 g/kg ADG (P > 0.05). Annual N fertilization with ammonium nitrate between 75 and 150 kg N/ha in palisadegrass pastures under continuous stocking enhances animal performance per unit area yet not affecting neither methane production nor intensity. [ABSTRACT FROM AUTHOR]

Sheep and goats present land stewards with a unique opportunity to graze areas that cattle cannot access and by consuming plants that cattle find unpalatable. While Alberta has a thriving sheep industry and ranks third in Canadian sheep and lamb inventories, producers continue to seek new opportunities to improve land stewardship and better understand grazing animal management. Resources are limited for flock managers that provide the details necessary to successfully graze sheep or goats and maintain forage health under typical and novel circumstances. These typical and uncommon grazing situations include invasive weeds, solar farms, low-quality marginal lands, forests, inner city vegetation control, and powerline cut blocks. In partnership with Lakeland College, the Alberta Lamb Producers and the Alberta Goat Association obtained funding from Alberta Environment and Parks through their Rangeland Sustainability Program to develop a Sheep/ Goat Vegetation Management Accreditation Course. In consultation with some knowledgeable Alberta sheep and goat producers, summer students developed a series of vegetation management modules for Alberta sheep and goat producers to learn best management practices for grazing forages under typical and unique situations. These modules form a vegetation management accreditation program. The modules include 1) Grazing Principles; 2) Grazing Forages – native and tame; 3) Stockmanship and Animal Welfare; 4) Building a Business Case; and 5) Unique Grazing – under solar panels, powerline cut blocks, meeting landscape goals and controlling invasive species, forest grazing, and urban grazing. The course will be offered through Lakeland College in the D2L continuing education platform after a group of sheep/ goat producers have gone through the course and provided their feedback. The D2L platform will monitor the number of producers and landowners who complete the course to determine the effectiveness of the project. The modules will educate flock owners and serve as a go-to resource for comprehensive grazing and sheep/goat management under specific situations. Stakeholders requiring or offering vegetation management services using livestock would benefit from these resources for contract and partnership development purposes. The project engages land and animal stakeholders to balance and show both perspectives and needs related to vegetation management. [ABSTRACT FROM AUTHOR]

Weed encroachment might reduce stocking rate and overall animal performance in grazing systems. In addition, weeds can affect soil organic carbon because of changes in primary productivity and belowground biomass compared with well managed pastures. This study assessed different levels of spiny pigweed (Amaranthus spinosus L.) encroachment on bermudagrass [Cynodon dactylon (L.) Pers.] pastures. Spiny pigweed was drilled onto bermudagrass pastures to create three levels of encroachment: weed free, medium encroachment, and high encroachment. The weed-free pastures were treated with herbicide to control weed encroachment, and the medium had strips where weeds were controlled and strips uncontrolled. The high encroachment had no weed control. Treatments (weed free, medium, and high) were allocated in a randomized complete block design. The spiny pigweed was drilled in 2020 and grazing occurred from 2021 to 2023. Soil samples were collected in October 2023 to assess soil organic carbon (C) stock by determining soil bulk density and soil C concentration in the 0- to 5- and 5- to 15-cm layers. Results indicated that weed-free and medium-encroached pastures had greater soil organic carbon stock (20.2 Mg C/ha) compared with the weed-infested pastures (17.2 Mg C/ha). Soil C concentration was similar, but soil bulk density was lower in the weed-infested pastures, affecting soil carbon stocks. [ABSTRACT FROM AUTHOR]

The circadian rhythm alters forage chemical composition by balancing processes of photosynthesis, respiration, and transpiration. Timing of moving animals to a new paddock in a rotationally stocked system may take advantage of potential improvements in forage quality. The objective of this study was to collate available peer-reviewed papers aiming at comparing the forage quality and grazing dairy cattle performance when moved to a new paddock either in the morning (a.m.) or afternoon (p.m.). Twenty-four studies were gathered in total, and the number of observations per variable varied according to its availability within the studies. Among forage chemical composition parameters, contents of dry matter (DM), total nonstructural carbohydrates (TNC), soluble carbohydrates (SC), starch, neutral-detergent fiber (NDF), aciddetergent fiber (ADF), acid-detergent lignin (ADL), ether extract (EE), crude protein (CP), and digestibility were assessed. The animal performance parameters included dry matter intake (DMI), milk yield (MY), energy-corrected milk yield (ECM), milk fat (MF) and milk protein (MP) contents, fat yield (FY), and protein yield (PY). A meta-analysis was performed according to a random effects model weighted by inverse variance (Comprehensive Meta-Analysis V3.3.070). Means, standard deviations or p-values, and number of observations were used to compute the effect sizes. Heterogeneity between observed effect sizes was examined with the Cochran’s Q test and the I2 statistic. The standardized mean difference was reported with its 95% confidence interval (CI), where positive values indicate an increment of p.m. compared with a.m., and negative values indicate a reduction. Statistical differences were declared significant at P ≤ 0.05, and trends were declared at P ≤ 0.10. Forage sampled in the p.m. had greater (P < 0.001) contents of DM, TNC, SC, starch, and digestibility by 19.8, 16.3, 21.3, 12.1, and 1.0%, while NDF (P < 0.001), ADF (P < 0.001), ADL (P < 0.001), and CP (P < 0.01) were decreased by 1.8, 2.4, 2.4, and 1.7% relative to a.m. forage, respectively (Table 1). Content of EE was not influenced (P > 0.05) by time. The ECM was 3.4% greater (P < 0.001) and the PY tended to be 3.7% greater (P = 0.07) for dairy cows moved in the p.m. compared with those moved in the a.m (Table 2). Dry matter intake, MY, MF, MP, and FY were not affected (P > 0.05) by time. Results indicate that even with considerable improvements of forage nutritive value in the afternoon, the benefits in terms of animal performance are small. Future studies assessing potential benefits of moving animals to a new paddock during the afternoon, should consider statistical power analysis and sample size calculation when designing the experiment. [ABSTRACT FROM AUTHOR]

Accurate and less laborious estimates of forage biomass are needed for research and management decisions in grazing lands. Our objective was to develop linear regressions to estimate forage biomass using canopy height in both native rangelands and introduced bermudagrass [Cynodon dactylon (L.) Pers.] pastures in the Cross Timbers and Southern Tallgrass Prairie Ecoregion. Twelve pastures averaging 26 acres each were equally distributed in two ranches located in the Love County, Southern Oklahoma. The native rangelands comprise native tall- and mid-grasses along with forbs and some woody shrub species. Little bluestem [Schizachyrium scoparium (Michx.) Nash] is the dominant species, with brome (Bromus L.), broomsedge bluestem (Andropogon virginicus L.), ragweed (Ambrosia psilostachya DC.), purpletop tridens [Tridens flavus (L.) Hitchc.), dropseed (Sporobolus R. Br.), and Indiangrass [Sorghastrum nutans (L.) Nash] commonly found. The introduced pastures are dominated by bermudagrass with cereal rye (Secale cereale L.) and horseweed [Conyza canadensis (L.) Cronquist] commonly found as well. Samples occurred at preand post-grazing conditions from summer 2022 to fall 2023. Measurements included canopy height and handclipping all herbaceous vegetation in a 0.25-m2 frame. Forage samples were fresh weighed then dried for 72 h at 60°C and reweighed. There were 760 and 786 samples collected at native and introduced pastures, respectively. Data were analyzed using PROC GLM of SAS (SAS Inst., Cary, NC) including canopy height (cm) and forage biomass [kg of dry matter (DM)/ha] as independent and dependent variables, respectively. Only regressions including all parameters as significant (P < 0.05) were selected, and coefficient of determination (R2) and root mean square error (RMSE) were used to evaluate the predictive ability of the regressions. There was a pasture type (native or introduced) × season interaction (P < 0.001). This interaction is likely explained by the dominant species in each pasture type across seasons as well as their phenological stage. For the native rangeland, the spring linear regression including the quadratic term had the best fit with the greatest R² (0.56) and the least RMSE (944 kg DM/ha; Table 1). Summer and fall regressions had R² of 0.45 and 0.24 and RMSE of 1139 and 1343, respectively. No regressions were selected for winter because parameters were not significant (P = 0.53 and P = 0.18). For the introduced bermudagrass pasture, regressions presented R2 ranging from 0.24 and 0.30 except during the winter (R² = 0.09). These results indicate that forage biomass can be acceptably estimated using canopy height only during spring in the native rangeland. [ABSTRACT FROM AUTHOR]

One of the constraints on advancing livestock research is the lack of large-scale quantification of physiological traits, a process often constrained by financial, labor-intensive, and scalability limitations, in addition to being traditionally performed through invasive methods. However, in the era of big data, the collection of large, extensive, and heterogeneous datasets via digital technologies, coupled with Artificial Intelligence (AI) techniques, has catalyzed significant progress across various research domains, including precision medicine, education, finance, and environmental and socioeconomic studies. This presentation will highlight our research efforts in employing computer vision systems (CVS). It will focus on a longitudinal study predicting body weight (BW) using a keypoint model. The discussion will include the advantages of using keypoints and 2D images to assess BW, which is important in the fields of animal growth and physiology in dairy and beef farm operations. We will also discuss the use of machine learning algorithms to early detect subclinical ketosis and locomotion problems in dairy cows. Lastly, this presentation will showcase the use of Unmanned Aerial Vehicles (UAVs) for pasture and soil management in grazing conditions. Our main goal with this presentation is to discuss how CVS and AI can generate valuable data in different areas, allowing for large-scale phenotyping, improving farm performance and sustainability. [ABSTRACT FROM AUTHOR]

Monitoring the diet consumed by grazing animals and relating that to health and performance is a task dating back to the origins of herding and pastoralism. Visual assessment of plants and animals by knowledgeable individuals has and will likely continue to be the most common manner of obtaining this information. It is part of the culture of livestock rearing and so even with the advent of modern analytical methods, adoption may be slow until the demographics of the industry change toward practitioners who have grown up with technology as part of their culture. Recent discussion within the rangeland profession has revolved around the art and science of grazing management, and thus grazing animal nutrition. These two skill sets are not mutually exclusive. I contend that art is the skilled application of science. With respect to the science, near infrared spectroscopy (NIRS) has been applied to determine the chemical content of feeds and forages. Fecal NIRS has been used to determine diet quality and composition in herbivores and results of this analysis can generate inputs to nutritional balance software that subsequently project animal performance. As described in the title, this presentation will involve a discussion of physics, math, chemistry, and biology. Regarding physics, the absorbance and reflection of near infrared energy by a population of chemical bonds ultimately described mathematically via multivariate statistics. Statistics that quantify the relationships between spectra and reference methods. Chemistry in this application quantifies constituents of interest in plant tissue consumed which are related to biology by way of intake, digestion, metabolism, and elimination of said grazed material. When projections of grazing animal performance are merged with landscape scale remotely sensed vegetation indices, the result is a powerful decision support system, provided by science, that facilitates the skill of the grazier; the artist if you will. [ABSTRACT FROM AUTHOR]

Parasitism in lambs during the post-weaning period has effects on growth, survival, and sheep enterprise profitability. Opportunities to minimize exposure to infective larvae during this period may reduce clinical effects and improve lamb performance. Native warm season grasses (NWSG) offer increased growth during summer months and taller plants that allow grazing at greater heights. The objective here was to evaluate NWSG as a forage for post-weaning development of lambs in spring lambing, forage-based systems. Over 2 yr, Katahdin lambs (Yr 1, n = 30; Yr 2, n = 31) were managed at a producer farm in the piedmont region of North Carolina. Beginning 2 wk post-weaning, lambs were randomly assigned to graze on either NWSG (Big Bluestem and Indiangrass) or cool season grass (CSG, Kentucky 31 Tall Fescue base) pasture. Lambs were continuously grazed for 70 d in Yr 1 and 55 d in Yr 2. Fecal egg count (FEC), FAMACHA score, and body weight (BW) were measured every two weeks. Lambs were dewormed at FAMACHA > 3. Forage analysis was conducted at the start and end of the grazing period. Statistical analysis were performance using the PROC Mixed procedure of SAS. Lambs in each group were raised in similar litter sizes and sire and sex were evenly distributed between groups. Fecal egg count and growth estimated breeding values (EBV) were similar between NWSG and CSG groups. In Yr 1 and 2, no differences were observed in FEC between grazing groups (P > 0.05). However, FEC did increase in both groups throughout the grazing period (P < 0.05). In Yr 1, no differences were observed in total BW gain (P = 0.74). However, in Yr 2, lambs grazing CSG had greater total BW gain than the NWSG group (P < 0.05). In both years, there were no differences in the percentage of lambs requiring deworming (Yr 1, P = 0.36; Yr 2, P = 0.47) but lambs requiring treatment had greater FEC EBVs (P < 0.05). Nutrient quality of NWSG pasture was reduced compared with CSG pastures. Total digestible nutrients and crude protein were less in NWSG compared with CSG pastures (Yr 2: 61.5% vs. 63.9% and 8.9% vs. 13.6%, respectively) and neutral detergent fiber was greater (Yr 2: 74.1% vs. 65.2%, respectively) resulting in decreased nutrient availability for NWSG group. While NWSG may provide additional biomass for summer grazing, rapid maturity rates may limit nutrient availability for lambs resulting in decreased growth performance despite similar levels of parasitism. Lamb FEC EBV may have a role in parasite resistance and deworming requirements regardless of forage type. Thus, genetics must be considered along with grazing management as part of an integrated parasite management plan. [ABSTRACT FROM AUTHOR]

Grassland stewards are seeking a better understanding of the complex interactions occurring in their pastures. Information is readily available to assist producers but each farm provides its own unique challenges and opportunities. A diverse scope of knowledge and skills are required to build resilient grazing systems. To address this need Amazing Grazing conducted a webinar series (April 2023) followed by on-farm workshops in July/August 2023. Webinars were held on consecutive Wednesday evenings with 237 average number of registered attendees and 78 average number of actual participants. Topics covered during the first webinar were pasture ecology basics, plant growth principles, livestock forage demand and grazing management principles. The following week covered pasture layout and design, pasture renovation techniques and pasture soil health concepts. The final evening featured topics on electric fence basics, grazing systems for horses and small ruminants and a synopsis. NC Extension Livestock Agents assisted in the sight selection and execution of workshops (n = 8) that were held on working farms. These events provide the opportunity for hands-on instruction to demonstrate the concepts covered in the webinar series. Total workshop registration was 196, with 148 evaluations completed. Participants were 72% farmers, 1% extension agents, 10% Soil and Water Conservation District Employee, 7% NRCS employee and 10% other. The total number of pasture hectares grazed by participants was 3,217 with 1,257 ha as hay. Livestock inventories for attendees were 4,323 beef cattle, 1,366 sheep, 455 goats and 51 horses. Attendees were asked about their pre- and post-workshop knowledge (1 = Very Low; 5 = Very High) of topics presented. Participants indicated a knowledge gain (average pre = 2.78 and post = 3.91) in Concepts of Pastureland Ecology, Adaptive Management, Managing Nutrient Distribution, Pasture Renovation, Temporary Electric Fence, Troubleshooting Electric Fence and Pasture Plant Identification. Workshop impact was determined by asking attendees their post workshop intentions regarding management practices (1 = No, 2 = Maybe, 3 = Yes, 4 = Already Doing). Attendees plan to spending more time walking pasture to determine plant condition, learn more about soil, plant, animal and human interactions, increase use of temporary electric fence and adopt an adaptive management style (average score = 3.91). Continued workshop participation indicates the demand for hands-on education in these areas and that the on-farm format is an effective teaching environment. [ABSTRACT FROM AUTHOR]

Extensive grazing systems often vary in pasture size and terrain, making it challenging for ranchers to accurately locate livestock through visual appraisal. Using satellite-based global positioning systems (GPS), accurate position data can be provided to track animal movements that could inform grazing management decisions. This study aimed to: 1) assess two modern GPS devices for functionality by calculating fix success rate, and 2) evaluate the relationship between average daily distance traveled and average daily weight gain (ADG) performance on yearling steers grazing smooth bromegrass pasture using the GPS devices. Yearling steers (n = 25) grazed a 10.8-ha smooth bromegrass pasture for 156 days from May to September 2021. The temperature ranged from 4.1 to 38.8℃ with an average 22.7℃ and received 490 mm of rainfall. Cattle ADG was 0.65 ± 0.13 kg/d. Each steer was assigned two GPS collars for 28 days to compare two types of sensors. The sensors evaluated were i-gotU GT-600 travel loggers (GU) and Yabby LoRaWAN GPS sensors (YB) utilizing the IoT (Internet of Things) technology. The YB sensor possessed real-time monitoring and remote data access, while data from the GU sensor needed to be removed from the animals and manually downloaded. The YB sensors had a manufacturer declared finest positioning accuracy of 4.6 m, while that of the GU sensor being 9.1 m. With a 10-min sampling rate, battery life of the YB sensors lasted 4 weeks, while the GU sensors demonstrated unreliable battery performance that ranged between 1 to 4 weeks. Fixed success rate (FSR) was calculated for each sensor. Using PROC MIXED of SAS (v 9.4), on average the GU sensors had a 67.1% FSR and the YB sensors observed an 89.9% FSR (P < 0.0001). The YB sensor outweighed the GU sensor on battery life and FSR, thus was utilized throughout the duration of the grazing season. Individual animal traveled distance was calculated after converting the GPS coordinates in decimal degrees to Universal Transverse Mercator coordinates (WGS 1984 UTM zone 14N) in meters. The Euclidean distance between consecutive coordinates was calculated and summed daily to represent the daily traveled distance of an animal. Using all coordinates recorded from YB, steers traveled 2,718 ± 809 m/d. Statistical analysis was conducted using PROC CORR of SAS to determine the correlation between the daily averages of distance traveled and ADG. All values were considered significant a = 0.05. There was no correlation observed between distance traveled and ADG (P = 0.76). Results demonstrate that modern GPS sensors utilizing IoT technology have benefits over traditional GPS sensors and can be used as a tool for extensive grazing livestock tracking. [ABSTRACT FROM AUTHOR]

Our objectives were to 1) determine diet selection of goats and cattle grazing woody plant-encroached tallgrass prairie, and, 2) determine the effect of the presence of goats on cattle diet selection. In 2019, pastures (n = 6) were allocated to 1 of 2 experimental grazing treatments. Pastures (n = 3) grazed by cattle only (crossbred Angus yearling heifers) were moderately grazed year-round at 4.2 ha per heifer. Pastures (n = 3) grazed by cattle (similar heifers) and goats (Boer x Spanish crossbred mature does) were moderately grazed year-round at 4.7 ha per heifer and 2.3 ha per goat simultaneously. Each pasture was burned in 6 patches (2 patches per year) to facilitate range management objectives. Every 35 d from May 2022 until June 2023, fecal samples were collected from all animals and stored frozen and later composited into 2 composites per animal species per pasture. Composites were then analyzed by a commercial lab with DNA barcoding and high-throughput sequencing. For statistical analysis, the top 50 Exact Sequence Variants (ESVs), representing species of forage, across all treatments were used for analysis. Each ESV was georeferenced to eliminate plants that did not grow in the study area, and assigned to a representative functional group: graminoid, forb, legume, and woody plant. Analysis of variance and Tukey's post-hoc separation of estimated marginal means were performed to assess the effects of season, grazer species, and the interaction. The interaction of season and grazer species was significant (P < 0.01) for the percentage of diet selected from each functional group of plants. As expected, goats selected a greater percentage of their diet as woody plants in summer (57%) and winter (74%) compared with cattle (27%). Cattle selected more grass in winter (34%) than goats (11%). Goats selected more forbs in spring (33%) than cattle (10%). However, goats selected a lesser percentage of their diet as legumes in summer (16%) than cattle (58%), which was unexpected. Overall, these results indicate that both species of grazers select a diverse diet from these diverse pastures, and selection is dynamic over time. Goat presence in a pasture does not seem to drastically alter cattle selection, actually complementing cattle in these pastures where goats can be used to target species cattle do not prefer. [ABSTRACT FROM AUTHOR]

Pastureland Ecology 1 is a 2-wk continuing education course taught by cooperating faculty at NC State University for USDA-NRCS Staff. The course was founded in the early 1990s and has been taught 23 times to over 500 participants from all 50 states. Participants primarily include grazing specialists, soil conservationists, and district conservationists. Instruction is split between classroom lectures and hands-on experience with grazing management. Lecture topics include; introduction to pasture ecology, principles of plant growth, determining animal forage needs, pasture design, principles of soil health, principles of grazing management, and grazing management systems for small ruminants, horses and cattle. Small groups of students work with groups of goats, sheep, horses, and beef cattle throughout the course, learning concepts of forage allocation, temporary electric fence, and adaptive management. Popular demonstrations developed over the years include; the reel race, dung beetle buckets, burying underwear to demonstrate soil health, exploring root diversity, and troubleshooting electric fence. Farm tours are conducted to show how concepts being taught are applied on commercial farms. In 2023 there were 29 students from 13 states including VA (4), MD (4), PA (3), OK (4), MI (1), UT (2), TN (3), WV (1), MA (1), OH (1), NM (1), WA (3), and RI (1). Participants had 8.4 ± 1.39 (AVG ± SEM) years of experience with NRCS with a range of 1 to 27 yr. Students self-assessed their understanding of major concepts before and after the course. On a 1 to 5 scale students increased their understanding by an average of 1.05 ± 0.129, averaged over all topics. Topics more familiar to participants had less increase including; Soil Health (0.38), Pasture Condition Evaluation (0.51), and Grazing Management for Beef Cattle (0.79). Less familiar topics had greater increases including Grazing Management for Horses (1.27) and Small Ruminants (1.27), and Temporary Electric Fence (1.43). Pastureland Ecology 1 remains a critical part of the Amazing Grazing Program at NC State University, impacting pasture-based livestock producers across the country. This educational model has proven to be an effective way of teaching the principles of pastureland ecology. [ABSTRACT FROM AUTHOR]

A mathematical model to estimate: a) the cost of beef cattle production in grazing systems; and b) the environmental sustainability of production systems using the Emergy Synthesis Model was evaluated. All items were considered and allocated, according to the precepts of the Economic Theory, under Fixed Cost (FC), Variable Cost (VC), and Total Cost (TC). The model estimated costs in the case-study for the entire property and the different production lots within the same property. Costs were allocated per animal and per kg of beef cattle produced. The total cost per animal of cattle produced was US$ 416.86. It was observed that the VC represented 66% of the TC. The cattle purchase price, including under VC, was the factor that represented the most significant portion of the production cost, in which the current operation reached 59% of the TC. Therefore, the currently developed tool may be used to facilitate understanding and potentially help to manage risk and profit. To examine from the environmental point of view, the synthesis of emergy was utilized. Emergy is the memory of the available energy used directly and indirectly to produce a service or product. It was observed that the property considered in the current case-study showed a renewability of 47.6%, indicating that less than one-half of all the energy used came from renewable resources. The emergetic yield ratio (EYR), which measures how much natural energy was incorporated into produced goods or services, was 1.91. The survey showed that the emergetic exchange ratio (EER), which indicates how balanced the exchange ratio between the energy in products and the energy gross revenue, was 12.45, showing that the system delivers much more energy than it receives in a monetary form. It seems like the current system analysis was highly dependent on cost-effective resources. The fuel used for pasture management services was the non-renewable resource that mostly affected the design. For the emergy synthesis, such input represented 51.2% of the total energy used, but from the economic point of view, such resource represented only 1% of the total production cost. The system could be less dependent on market variability if good pasture management practices were adopted, such as using a reasonable pasture stocking rate. By using the emergy indexes, it was possible to analyze the cattle system from an environmental perspective, allowing to assist technology/technique adoptions capable of increasing the sustainability indicators, which has been recently valued by worldwide beef consumers. [ABSTRACT FROM AUTHOR]

Larkspur (Delphinium spp.) poisoning is a long-term problem for cattle grazing on rangelands of western North America. Results from preliminary experiments have suggested that differences in larkspur toxicity may exist between heifers and bulls. The objective of this study was to compare the physiological responses of yearling Angus heifers, steers, and bulls with a standardized dose of Delphinium barbeyi and to test the hypothesis that the response is sex dependent. Clinical signs of intoxication, including muscle coordination and function, were measured 24 h after oral dosing with larkspur by walking the cattle at a pace of 5 to 6 km h−1 for up to 40 min on an oval dirt track. Due to the experimental methods used, the variation in susceptibility to larkspur was not quantifiable for walking times of 0 or 40 min or more. Larkspur susceptible animals that were not able to walk (0 min; 36% of the animals) or larkspur resistant animals that walked the entire test period of 40 min (9% of the animals) resulted in censored or truncated data. The statistical methods (censReg and lmec) were used to adjust for data truncation or censoring. The heifers were only able to walk −8.9 ± 3.9 min (65.5% censored on the left) compared with 13.2 ± 3.7 min for bulls and 15.9 ± 2.7 min for steers. When heifers were compared with bulls and steers together, heifers walked 23.4 ± 4.5 min less (P < 0.0001). Serum alkaloid concentrations were measured immediately before walking, and deltaline concentrations averaged 266 ± 28, 131 ± 20, and 219 ± 28 ng mL−1 for all heifers, steers, and bulls, respectively, and serum methyllycaconitine concentrations averaged 660 ± 46, 397 ± 32, and 612 ± 34 ng mL−1 for all heifers, steers, and bulls, respectively. The relative risk of a zero walk time for yearling heifers is 330% that of yearling bulls (P = 0.0008). These results suggest that yearling Angus heifers are more susceptible to larkspur intoxication and, when possible, heifers should be kept from grazing larkspur-infested rangelands as a simple management tool to reduce the risk of fatal poisoning. [ABSTRACT FROM AUTHOR]

Beef cow herds are expected to be metabolically and reproductively efficient in varied and ever changing environmental conditions. Therefore, selection and management of grazing beef cows provides unique and diverse challenges in achieving optimal production efficiency for any environment. Beef cows face dynamic and highly variable nutritional environments that periodically are inadequate in meeting nutrient and energy requirements. Nutritional management during high metabolically stressed and key physiological states can lead to increased or decreased metabolic efficiency. Conversely, cow metabolic efficiency may be reduced in many production systems due to surplus nutritional inputs and reduced exposure to environmental stressors. Alternatively, metabolically potent supplementation strategies targeting enhanced energy metabolism and endocrine mechanisms would increase beef cow metabolic and economic efficiency. Metabolic efficient beef cows adapt to environmental changes by adjusting their metabolic energy utilization in order to match current environmental conditions and remain reproductively competent. This mechanism involves adaptive processes that drive adjustments in nutrient partitioning and energy utilization efficiency. However, the variation in metabolic and reproductive efficiency among beef cows within cow/calf production systems is substantial, suggesting a lack of complete integration of nutrition, genetics, and reproduction with environmental constraints and conditions. Better integration and understanding of the interactions may lead to advancements in metabolic efficiency of the cowherd. Metabolic flexibility is recognized as an important trait in dairy production but has received little attention thus far in beef cattle. Overall, management and supplementation strategies in cow/calf systems from a mechanistic, targeted nutritional approach during key physiological periods would hasten improvements in metabolic efficiency. [ABSTRACT FROM AUTHOR]

Predicting dry matter intake (DMI) for beef cattle on extensive rangelands presents a significant challenge to determining stocking rates. Traditionally, DMI is estimated by taking full body weight (BW) multiplied by a percentage selected based on animal class, production phase, and forage quality, which introduces tremendous levels of accumulated error at the herd level. Animal Unit Months (AUMs) are utilized to simplify the determination of stocking rate (animal units per area per a specific period of time) of pastures. This challenge represents a tremendous opportunity to leverage precision technology to account for individual animal variation in BW and growth, with subsequent impacts on herd-level decisions. Therefore, the objective of this study was to utilize precision livestock technology (PLT) collected data to build a precision system model (PSM) to evaluate the differences in predicted DMI using either initial BW, expected midseason BW, or PLT measured BW. The PSM model was built utilizing BW data measured using SmartScale (C-Lock Inc.) for 60 days during the summers of 2021 and 2022 on Angus yearling steers (average initial BW 393.71 ± 39.01 and 315.23 ± 53.91 kg, n = 130 and 124, for year 2021 and 2022, respectively) on native pastures at the South Dakota State University Cottonwood Field Station. The PSM evaluated total forage consumption and deterministically estimated hectares of pasture required to meet the herd forage demands relative to available biomass (kg/ha). the PSM estimated 4.49% and 6.94% more DMI at the herd level compared with using initial BW for years 2021 and 22, respectively, and 1.64% less DMI than mid-season BW in 2021. This resulted in an additional 14.03 and 17.95 ha required for years 2021 and 22, respectively, according to PSM estimates compared with initial BW, while animals were understocked by 5 and 0.3 ha for 2021 and 2022, respectively, using mid-season BW. Individuals expressed a divergent growth rate, resulting in greater misalignment between static and PSM predicted DMI as the grazing period progressed (Menendez et al., 2023), indicating greater opportunities for targeted grazing management in long grazing periods. Therefore, applying precision data provides more precise DMI estimates and demonstrates the advantages and disadvantages of herd-level estimates. The use of PSM helps to identify high-leverage precision tools to minimize a performance gap like overgrazing extensive rangeland systems and demonstrates the critical need to develop robust data-collection and processing steps to leverage continuously collected PLT data. [ABSTRACT FROM AUTHOR]

Virtual fencing is a promising alternative to contain livestock dispersal without using physical barriers. This technology uses smart-wearable collars that deliver predictable warning tones to animals when they approach virtual boundaries paired with mild electric pulses. Virtual fencing allows for dynamic management of livestock grazing, based on site-specific variations in the quality and quantity of forages. However, several factors can affect the efficacy of virtual fencing, including the length of prior experience with virtual fencing, climatic conditions, forage availability inside and outside virtual fencing paddocks and collar configuration schedules. Lactation requirements and social interactions between collared cows and uncollared calves can also influence the efficacy of the technology. Virtual fencing trials were conducted at the New Mexico State University's Chihuahuan Desert Rangeland Research Center from August 27 to December 21 of 2022 to evaluate the efficacy of virtual fencing to manage rangeland cows during late lactation and following weaning. Twenty-six Brangus cows previously trained to use NoFence C2 collars (NoFence, Batnfjordsøra, Norway), were monitored for 30 days during late lactation and 28 days after weaning. Collared cows and uncollared calf pairs were allocated to four virtual fence pastures in late lactation and after weaning, with pasture duration (4.2 ± 0.6 d), size (72 ± 19 ha) and perimeter (4,523 ± 352 m) varying according to forage availability and access to fresh drinking water. Audio cues, electric pulses and ratio of electric pulses to audio cues before and after weaning were compared by ANOVA in a Completely Randomized Design replicated across pre-weaning and post-weaning pastures (n = 8). The average number of electric pulses per cow was greater (P < 0.0004) for pre-weaning (3.7 ± 0.2) than for post-weaning post-weaning (1.6 ± 0.3) pastures. The number of audio warnings per cow was also greater (P < 0.0001) for pre-weaning (52 ± 3.3) than post-weaning (34 ± 3.3) pastures. Conversely, cows had decreased (P < 0.0001) ratios of electric pulses relative to audio tones on post-weaning (4.8 ± 0.5%) than pre-weaning (7.0 ± 0.8%) pastures. These results suggest that cows responded better to virtual fencing after weaning, likely because weaned cows were no longer affected by social interactions with uncollared calves. Furthermore, cows after weaning apparently relied on warning tones and fewer electric pulses to interact safely with virtual fences. However, it is important to note that sources of variation not accounted for or controlled by the present experimental design may have also affected the recorded interactions with virtual fences in the present study. [ABSTRACT FROM AUTHOR]

Virtual fencing (VF) enables livestock grazing without physical fences by conditioning animals to an audio tone (AT) followed by an electric pulse (EP) that is up to 25 times weaker than conventional electric fencing (EF). However, the operating principle of a virtual fencing system raises concerns about animal welfare. Therefore, the present study investigated the learning process of dairy cows in a virtual fencing environment and its effects on animal behavior and welfare. Twenty lactating cows were divided into four groups of five individuals each (2x VF; 2x EF), balanced by lactation stage (203 ± 62 days) and age (3.7 ± 1.5 lactations). All cows were accustomed to daily grazing with EF but were naïve to VF. Each group grazed in a separate paddock for 3 days of acclimation (P0) and 21, 14, 14, and 7 days of experimental treatment (P1-4). All paddocks were electrically fenced, and of similar vegetation structure and botanical composition. During P1-P4, a virtual boundary was activated within each paddock of the VF groups, and a second electric fence was set up within each paddock of the EF groups to maintain comparable paddock sizes. All cows were fitted with a VF collar (Nofence AS, Batnfjordsøra, Norway) and an IceQube pedometer (Peacock Technology Ltd, Stirling, UK). The sensors continuously tracked cow positions, the daily numbers of AT and EP, and activity behavior, respectively. Throughout P0-P4, daily milk yield, feed intake, and body weight were recorded. A total of 26 milk samples were collected per cow to determine milk cortisol concentrations. Behavioral observations were conducted for 2 h on 23 days to record agonistic behaviors, vocalizations, and excretions. During P1-P4, each cow received an average of 1.9 ± 3.3 AT and 0.1 ± 0.7 EP per day. The total number of stimuli ranged from 37 to 225 AT and 3 to 11 EP per cow throughout the experimental period, indicating individual variations in learning (P < 0.003). Within the first three days after virtual fence activation, most cows learned the concept of the VF system. The conditioning of the cows was successful at herd level after three repetitions at a new virtual boundary, reflected by a decreasing ratio of mean EP/AT from 20 to 3, 2, and 0 % with each paddock change. Milk yield and cortisol, feed intake, body weight, and cow activity did not differ between VF and EF groups. Overall, there were a mean of 11.2 vocalizations and 5.9 displacements more per cow in the VF groups (P < 0.05), but similar across P0-P4. Our results suggest that learning the virtual fencing system did not lead to lasting adverse effects on cow welfare. [ABSTRACT FROM AUTHOR]

There is an increased interest in the use of climate-smart practices and technologies to be more effective in climate change mitigation. These practices include grazing management, pasture management, animal and herd management, animal disease and health, animal breeding, and supplemental feeding during the stocker phase. In the feedlot sector, climatesmart practices range from supply chain challenges including climate smart adaptation by crop producers, cattle type, manure management, health management, and use of growth promoting technologies. There are certainly other technologies not mentioned and are not meant to be marginalized. During the stocker phase, grazing management is highly variable and dependent on climatic conditions and variability, plant species and plant health, water management, soil health, and cattle type. A correct balance among the different land managers, government agencies, and recommendations from university researchers and Extension personnel should optimize these practices. For instance, there is a focus on rotational grazing to increase the efficiency of grazing management. However, in the southwestern U.S. this practice may not be practical given the vast area and landscape used in production. In certain geographical areas, pasture management is becoming increasingly important as decreasing water sources (particularly aquafer levels) are apparent. Some data suggests that now is the time to change from cereal crop production to perennial forages while water is still available to establish the forages. This, in turn, may improve soil health and carbon sequestration. However, as with all mitigation strategies, this may decrease supply of cereal grains available to small feedlot producers, albeit a significant amount of cereals are transported to the cattle feeding sector. Animal breeding programs to improved production, heat tolerance, disease resistance, and improved reproduction is important. As with any production practice, supplementation programs may become necessary under certain situations. It is well known that cattle treated for respiratory disease have poorer performance and carcass characteristics than cattle not treated. Use of growth promoting technologies improve animal performance and decreases total methane produced. No doubt manure production from feeding operations produce methane. Dairy and swine operations can harvest the methane and with use of biogas collectors flare off the methane or produce energy for electric generators, however, this is not practical under feedlot situations; however, application of manure to land may improve soil organic matter. Building resilience in evaluating climate-smart practices will satisfy multiple objectives including impacting food security without many constraints to adoption. [ABSTRACT FROM AUTHOR]

Livestock's environmental footprint has become a pivotal concern for both consumers and investment corporations. To stay competitive in the sustainable foods movement, the beef industry has sought to improve sustainability within their own supply chains. However, before system sustainability can be achieved, more sustainability practices must be adopted and implemented by the foundation of the system. Therefore, to gain insight into motivations of ranchers for adopting new sustainable practices we administered an online multi-state survey to cattle ranchers in collaboration with state Cattlemen's Associations. In total, the survey consisted of 45 questions and was divided into four sections including: 1) rancher demographics, 2) ranching educational resources, 3) current best management practices, and 4) willingness to join new rancher sustainability program. Of the survey participants (n = 884), when asked what made them trust/believe in a ranching educational program, 64% of ranchers stated they trusted (very or extremely) science, 55% or ranchers stated they trusted a ranching educational program if the program was partnered with state cattlemen's associations, and 32% of ranchers stated they trusted the program if other ranchers they knew were currently enrolled in the program. When survey participants were asked who they trusted most to dispense ranching educational information 79% trusted veterinarians (very or extremely), 63% trusted extension agents/farm advisors, 57% trusted professors (very or extremely), and 54% trusted other cattle producers. In regards to where cattlemen acquired ranching information 94% utilized trade publications or magazines, 90% utilized university or extension, 70% utilized state or national cattlemen's meetings, and 52% utilized social media. The top three reasons why survey participants would choose to adopt a new ranching practice included increases profitability 79%, improves animal health 78%, and expected benefits greatly outright the cost or effort to implement 51%. Meanwhile, only 18% of ranchers selected improving environmental health as one of their top 3 reasons for adopting a new ranching practice. In terms of best management practices, 77% of producers stated they had a grazing management practice, however only 29% had their plane written down. Finally, the survey indicated that ranchers who were male, had been through the Beef Quality Assurance training, and were enrolled in a land assistance program were more likely to state that joining a sustainability program would be beneficial to their operation (P < 0.05). Overall, this survey provides the necessary insight into why and how ranchers learn about new ranching practices and provides a possible framework for how to develop successful ranching educational and sustainability programs in the future. [ABSTRACT FROM AUTHOR]

A high prevalence of diseases and parasites is one of the major constraints in the small-ruminant industry in the Southeast because of its warm and humid climate, and poor management practices. Drug resistance developing in pathogens, and the lack of access of producers to and affordability for veterinarians practicing in small ruminants warranted us to look for integrated preventive approaches. To promote integrated approaches for preventing diseases and parasites in small ruminants, a team of scientists and professionals from five institutions (Tuskegee University, Fort Valley State University, USDA-ARS Booneville, University of Arkansas, and the University of Maryland Eastern-Shore) worked together with an objective to develop curricula (training handbook) and train the trainers (educators) and small-ruminant producers in the Southeast. The Training Handbook consisted of nine chapters authored by project collaborators and invited experts. Relevant aspects of keeping small ruminants healthy and preventing possible diseases and parasites, including basic facilities and health care, suitable sites, grazing systems and management, biosecurity, selection and breeding, nutrition, and economics have been presented and discussed in the Handbook. After the handbook was developed, a 3-day train-the-trainers training was conducted at Tuskegee University. County agents, specialists, and technical-service providers working at various land-grant universities and other institutions working with small-ruminant producers or their educators were invited to participate in the training. Additionally, selected lead producers raising small ruminants from Alabama and graduate students working on small-ruminant research and outreach were invited to the training. Twelve professionals from four different states (Alabama, Georgia, Mississippi, and North Carolina) six farmers, and four graduate students attended the training. Training included indoor sessions with presentations, discussions, and question-answer sessions. Outdoor sessions included demonstrations, hands-on activities, and tours of the small-ruminant production sites and facilities. Evaluations by participants were conducted before adjournment on the same day or at the beginning on the next day. Most participants expressed that presented topics, hands-on activities, demonstration, and tours were extremely useful (71-85%) or very useful (13-23%). They stated that they were extremely likely (73-89%) or very likely (11-23%) to apply what was learned from the training. Similarly, most participants reported that the ultimate condition of small-ruminant health would be improved if the learned knowledge and skills are applied on the farms (producers) or on education endeavors (professionals) with most improvements (64-83%) or reasonable improvements (15-21%). Evaluations by participants showed that the training handbook and the overall training could be very useful to improve health of small ruminants significantly. [ABSTRACT FROM AUTHOR]

The beef sector is facing mounting challenges related to its perceived impact on climate change and other negative ecological externalities that can occur from the rearing of beef cattle. This would include greenhouse gas emissions (GHG), soil degradation, eutrophication of water ways and a decrease in biodiversity, to name a few. Within the industry, the largest contributor of GHG comes from the grazing sector, predominantly in the form of enteric methane (CH4) produced during the reticulo-rumen fermentation process. This presents a unique challenge, as the grazing sector is one where animal scientists have low precision with respect to experimental design and data collection, and where producers assert a lower level of dietary control relative to confined operations. While enteric CH4 inhibitors are getting closer to regulatory approval, their ability to reduce emissions in grazing systems is still relatively unknown due to the "pulse" supplementation strategy being unstudied to date. Therefore, management decisions that improve the quality of the forage base are the most practical strategies to reduce enteric CH4 production. This would include strategies such as adaptive grazing management, inclusion of high-quality forages, and improved forage diversity as potential tools to reduce emissions, dependent on geographic location. Furthermore, how the human dimension influences soil-plant-animal interrelationships may lead to beneficial ecological outcomes such as carbon sequestration and soil health. Therefore, potential "win-win" outcomes may be achieved. However, climatic gradients, and more specifically moisture, can influence or limit outcomes and thus interpreting research should be done on a geographical and climatic specific basis. The objective of this presentation is to outline and examine how management decisions can influence the efficiency and environmental impact of U.S. beef production, and to identify potential limitations and knowledge gaps in need of future research. [ABSTRACT FROM AUTHOR]

Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A 2-yr experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 d (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at 5 points above the canopy for each paddock using a canopy analyzer. For all treatments, the postgrazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre- and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited NDF intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible OM (P = 0.007) and the ratio of CP/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency of microbial synthesis (P = 0.023) were greater at 95LI and 90LI, followed by 42D and less at 100LI. Overall, the range from 90% to 95% of LI is the recommendation to interrupt the rest period, since this strategy enhanced community stability, forage intake, and nutritional value of the diet. Under on-farm conditions, brachiaria grass and forage peanut pastures should be managed at a range height of 24 to 30 cm. [ABSTRACT FROM AUTHOR]

To ensure long-term sustainability and ecological resilience of agroecosystems, agricultural production should be guided by policies to ensure regenerative cropping and grazing management protocols. Changing current unsustainable high-input agricultural practices to low-input practices that regenerate ecosystem function will be necessary for sustainable, resilient agroeco-systems. Effective soil management provides the greatest potential for achieving sustainable use of agricultural land with rapidly changing, uncertain and variable climate. With appropriate management of grazing enterprises, soil function can be regenerated to improve essential ecosystem services and farm profitability. Affected ecosystem services include carbon sequestration, water infiltration, soil fertility, nutrient cycling, soil formation, biodiversity, wildlife habitat, and increased ecosystem stability and resilience. Collectively, conservation agriculture managed regeneratively supports ecologically healthy, resilient agroeco-systems and enhances watershed function. To accomplish this, it is important for scientists to partner with farmers who have improved the environment and excel financially to convert experimental results into sound environmental, social, and economic benefits regionally and globally. Benefits include addressing questions at commercial scale; integrating component science into whole-system responses; identifying emergent properties and unintended consequences; incorporating pro-active management to achieve desired goals under changing circumstances; and including the potential of the human element to achieve superior economic and environmental goals. Developing and implementing regenerative management protocols that include ruminant grazing animals will be necessary to ensure long-term sustainability and ecological resilience of agroecosystems. [ABSTRACT FROM AUTHOR]

The dearth of individual performance records derived from an extensively driven production system coupled with the impracticality of utilizing reproductive technologies makes commercial genetic improvement challenging in small ruminants. We collaborated with five producers throughout California to assess how electronic ID (EID) and genetic testing could inform ram selection. Our objective was to determine how the data collected from these technologies could augment genetic improvement on commercial ranches. Familiarity and use of EID tags on ranches at the start of the research varied; thus, allowing for a qualitative reflection on the participant's perceptions of the usefulness of this technology. Ear notch samples were collected and EID ear tags were placed in 2,963 sheep; 305 rams, and 2,658 of their potential progeny. We partnered with Superior Farms (Dixon, CA) to genotype the animals using their Flock54 single nucleotide polymorphism panel which contains 956 markers for assigning parentage, and includes markers linked to quantitative trait loci and/or known single gene causative markers to aid in disease management. SNP data was used to assign paternity and determine sire prolificacy. A total of 524 carcass samples from ram lambs from two of the ranches were processed at Superior Farms' plant and assessed with a USDAapproved camera grading system (e+v, Oranienburg, Germany) that matches EID’s to carcass data. Progeny contemporary group deviations were calculated for hot carcass weight, yield grade, and ovine cutability calculation (OCC) which predicts the yield of edible product on the carcass. The average number of lambs per sire born at each ranch and the mean OCC of the progeny for each sire were compared using a one-way analysis of variance. There was a significant ranch effect on the average progeny number per ram (P < 0.05). The ranch with the lowest ram to ewe ratio (1:10) also has the lowest average progeny per ram and the ranch with the greatest ratio (1:50) has the most progeny per ram. There was a large range in the number of lambs per sire (0-135) within each ranch. There was a significant sire effect (P < 0.05) on average OCC within each progeny contemporary group, meaning some sires were producing offspring with significantly more marketable meat. The use of EIDs in combination with genetic testing, allowed for the collection of individual progeny performance data. This provided insight into sire performance and identified prolific sires that were also producing lambs with superior carcass merit. Producers could use this information to select for high-performing rams; however, there is an unavoidable delay between ram turnout and the collection of progeny carcass data. This limits the practical utility of these data and reinforces the value of having estimated breeding values available at ram purchase to select genetically superior rams. [ABSTRACT FROM AUTHOR]

Cow-calf farms are abundant across the southeastern US and there is a wide diversity of farm sizes and types of farmers. Farms include small-scale part-time farms, and large commercial-scale farms, often integrated with other farm enterprises. Many farmers have full-time employment off the farm and little if any hired labor, such that there is little time to devote to farming activities. In contrast, large farms often have access to labor, equipment and other inputs that may not be available to small farms. The diversity of farms and farmer demographics makes extension programming challenging as motivational factors vary considerably. Many pasture management practices proven by research have very low levels of adoption including active grazing management, pasture renovation, hay testing, etc. We assume that all farmers are focused on profitability, but this is clearly not the case especially with small part-time farmers. Other motivations may be enjoyment of spending time with animals, time spent with family, improving animal welfare, interest in machinery and "gadgets", and other nonfarm interests including using a cow-calf enterprise to hold land in some kind of agriculture for future development. New management practices may make sense from a profitability perspective but might require the development of new skills that the farmer does not have. Additionally, there may be other barriers including access to necessary equipment, conflicting information provided by advisers, and expertise in simple practices such as planting and spraying. As an example, novel endophyte tall fescue (NETF) has potential to eliminate the negative aspects of endophyte infected tall fescue while maintaining the desirable agronomic characteristics. While NETF technology is research proven and has been available to producers for over two decades, adoption has been very slow. The Alliance for Grassland Renewal is a multi-state private/public collaborative formed to promote the appropriate adoption of NETF. The Alliance conducts workshops to teach farmers and their advisors about how to best implement the NETF technology. The collaborative effort provides a more uniform set of recommendations than was formerly available through each member state. Through workshop evaluations we found several important factors that limit adoption including 1) the balance of cost and benefit is unclear, 2) farmers have limited financial resources, 3) the land is rented or unsuitable for renovation, and 4) farmers lack of knowledge, and 5) farm forage reserves are limiting. Many of these pasture management practices are difficult to adopt because they require many sequential steps that must be completed in a timely way. This may leave the farmer hesitant to take the first step in the process. For practices that are very different than standard management, use of on-farm demonstrations and hands-on learning have proven valuable. [ABSTRACT FROM AUTHOR]

The primary objectives of forage-based livestock grazing systems are to enhance sustainability of pastures and cattle production, and to maintain economic stability in the presence of changes in input costs and returns. Grazing management strategies and implementation vary for adapted forages according to vegetational-hardiness zones, livestock production objectives, and manager preferences for grazing systems, stocking rates, and stocking methods. Stocking methods are strategies or techniques to manipulate grazing animals in space and time and may be considered as variations of continuous or rotational stocking. In many stocking method discussions, the debates are often focused on experimental confirmational data vs testimonials and perceptions. Acceptable methodology and statistical analyses of grazing experimentation on continuous vs rotational stocking provides repeated measures of forage nutritive value, forage mass, grazing intensity, and stocking rate on gain per animal, gain per unit land area. Additional measurements may include effects on forage stand maintenance and soil nutrient analyses-status. Recent adaptations of mob stocking and intensive rotational grazing via popular press and consultants have received acclaims for methods to enhance ecosystem services, soil health, and other non-experimentally documented attributes. Managers may adopt these testimonials of stocking methods of 60 days or more deferment based on their perception of protecting and enhancing the environment rather than logic of seeking experimental evidence. However, when given a choice of forage available for consumption, cattle select more than 80% of their diet as leaves. Thus, with respect to average daily gain per animal (ADG), only a small percentage of pasture studies have shown an advantage for rotational stocking. The lack of ADG was attributed to reduced nutritive value of forage available for selection during the residence time. Selecting management and stocking strategies for optimum utilization for forage produced, individual animal performance, and overall gain per unit land area has led to flexible grazing systems. These grazing systems may not be "hardcore rotationally, time-scheduled stocked," but they do involve multiple pastures with strategies to incorporate movement of cattle based on current paddock forage status and forage mass estimates for desired animal performance. Grazing management strategies control the degree of intensity of beef cattle production based on level of economic risk and desired-expected environmental stewardship goals. Of all the strategies that management may adopt for grazing, the primary factor that controls resultant sustainability of pastures is that of grazing intensity as measured by stocking rate or forage height-density. Implementing revised or new management strategies requires attention to detail and the use of data-results-recommendations from comparative experiments conducted by a recognized source without conflict of interest in the method promoted. [ABSTRACT FROM AUTHOR]

Assertions about grazing management and grazing systems should be evaluated based on the scientific literature. Prior assumptions can limit our ability to achieve constructive dialogue regarding the merits of various stocking methods. These include the assumption that rotational stocking is inherently superior to continuous stocking, regardless of the nature of the overall grazing system, and the presumption that continuous stocking implies overgrazing. We revisited assertions about grazing management in general, but more specifically the choice of the stocking method, and considered their merit in the context of evidence from the literature, including a chapter titled Prescribed Grazing on Pasturelands from a National Resource Conservation Service (NRCS) literature synthesis published in 2012. We framed those assertions in the form of questions. The questions were: a) Does choice of rotational stocking ensure well-managed pastures?, b) Does rotational stocking result in greater accumulation of soil carbon than continuous stocking?, c) Does rotational stocking increase pasture productivity and optimal stocking rate compared with continuous stocking?, d) Does forage nutritive value and individual animal performance increase in rotational versus continuous stocking?, and e) Do pastures "look better" in rotational versus continuous stocking?. The objectives were to consider whether these often-stated assertions about grazing management were supported, refuted, or simply not adequately assessed by the body of scientific evidence. It is important to recognize that choice of stocking method is only one element of grazing management and grazing management is only one element of a grazing system. Thus, stocking method is "one piece of a very large pie". Additionally, stocking rate (grazing intensity) is a separate and independent grazing management choice from stocking method, such that both rotationally and continuously stocked pastures can be understocked, overstocked, or optimally stocked. It is unfortunate that choice of stocking method dominates discussions of improving grazing management to the expense of other issues, when in fact intensity of grazing has been shown conclusively to be the most important determinant of a wide array of soil, plant, animal, and ecosystem responses. We have observed that terminology such us regenerative grazing, holistic planned grazing, adaptative multipaddock grazing, management intensive grazing, high intensity low frequency grazing, and others, arise frequently and can dominate discussions in the realm of education, outreach and engagement programs in pasture-based livestock systems. These words/themes lack clear definition, and this lack of specificity may promote misconceptions, thus hindering the opportunity for critical thinking and ultimately the advancement and improvement of grazing systems. Educational efforts in pasture management should strive to remain relevant by focusing on experimental evidence. Local (i.e., state or county level) outreach and engagement programs are challenged with providing timely and specific information with implementable guidelines based on frequent observations at the landscape and farm levels. [ABSTRACT FROM AUTHOR]

Feeding the cow herd is costly. However, within grazing systems, identifying differences in efficiencies is difficult since forage intakes are rarely measured. Saturated hydrocarbons (n-alkanes; ALK) and long-chain alcohols are being used to estimate diet composition and intake. The robustness of this method depends on consistently quantifying the plant-wax contents of plants, and using them to delineate the composition of forage communities. The objectives of this study were to test both steps of this process, focusing on its potential to discriminate the dietary composition of cattle grazing rangelands. Three technicians in 2 labs measured C27, C29, C31 and C33 concentrations in pure and 9 mixtures of tall fescue and red clover. Measurement error between labs, and technicians within lab, were quantified. Botanical compositions were estimated with non-negative least squares (NNLS), and reliability assessed by regressing estimated on actual fescue proportions. Three cool- and 3 warm-season grasses, and 2 legumes, typical of western rangelands were harvested at 2 phenologies (vegetative; mature). As additions, C35, and the alcohols C24–OH, C26–OH, C28–OH, C30–OH, and C32–OH concentrations were obtained. Marker profiles of the 8 plant species were discriminated with principal component analysis. Cattle diets were simulated and their species composition estimated with NNLS. For the tall fescue and red clover mixtures, labs, and technicians within labs, differed in their quantification of individual ALK (P < 0.001). However, within technician, fescue contents of the mixtures were estimated reliably (P > 0.12), although consistently high for 2 technicians. At both phenologies, legumes were distinct from grasses, reflecting higher C29, C26–OH and C30–OH concentrations. Blue grama was unique in its C33and C32–OH contents. Still, the 8 plant species could not be clearly discriminated. Matrices of plant-wax marker concentrations had high condition numbers ( > 600), indicating collinearity. Composition of simulated diets were poorly estimated with NNLS, with large normalized mean square errors ( > 422). In conclusion, comprehensive training of technicians analyzing plant-wax contents of plants is vital for reliable use of this methodology. Even with such training, this procedure does not currently provide an accurate method to estimate the species composition of diverse diets common to rangelands. Refinements to the predictive framework are needed for its application in such settings. [ABSTRACT FROM AUTHOR]

Extensive grazing systems are subjected to constant variation in energy supply and International meat prices. In this context, animal energetics need to increase energy efficiency by strengthening the metabolic pathways toward productive/reproductive functions, with low-cost but high-impact management tools. In beef cow-calf grazing systems, grazing management, cow genotype and suckling restriction and flushing at the beginning of the mating period altered energetic efficiency as they modified nutrient partitioning from maintenance and milk production toward resumption of the estrous cycle and pregnancy. We presented a review with three research sub-models of research to improve, with low-cost management tools, beef cow productivity in grazing systems while attempting to alleviate weather variability. The first sub-model identified the optimum cow BCS at calving to achieve high pregnancy rate and its interaction with suckling restriction to improve weaning rate. Optimal cow BCS at calving can be achieved by herbage height manipulation throughout the beef cow-calf cycle. The second research sub-model focused on improve reproductive performance of primiparous beef cows that calved in suboptimal BCS (< 5). Suckling restriction for 12 d before a short-term supplementation (flushing) with rice bran for 22 d, increased probability of early pregnancy by 40%. Pregnancy rate was also modulated by cow BCS at calving, and was related to increased plasma insulin and IGF-I concentrations. The third sub-model incorporated herbage allowance and cow genotype through the entire beef cow production cycle and their interaction with suckling restriction and flushing. Collectively this approach was used to understand the relationships between herbage and animal productivity, stocking rate and individual and per ha production. High herbage allowance increased herbage productivity, cow herbage intake, and conversion efficiency of energy intake into calf product. Cow genotype increased herbage intake and conversion efficiency of energy intake into calf product due to greater calf BW and pregnancy rate. All together, the strategic and tactical tools used in these research models manipulated animal bioenergetics by increasing cow energy intake, changing nutrient partitioning and increasing productivity– per animal and per ha– and production efficiency of cow-calf systems in Campos grasslands. [ABSTRACT FROM AUTHOR]

The purpose of this review is to emphasize rangeland and landscape attributes that effect animal grazing behavior while highlighting successful approaches that have utilized this knowledge to devise supplementation strategies that improve the sustainability of grazing systems through modification of grazing behavior and pasture distribution, irrespective of animal nutrient requirements. Consequently, supplementation strategies are no longer formulated with the sole objective of addressing animal nutrient requirements. One of the principle drivers for this change in management philosophy is rangelands have become valued for many ecological services beyond forage for livestock. The threat of litigation and/or legal mandates that require land managers to consider the ecological, social, and economic impact of management decisions has increased scrutiny of livestock grazing. This has resulted in a significant body of research evaluating the ability of supplementation strategies to maintain or improve rangeland health and ecological function in a way that is economically viable. Herein, we will review the use of supplementation practices to alter livestock grazing location and control invasive species. Also, we will discuss the use of complimentary forages to bridge periods of inadequate forage quality. Rangeland-based livestock producers utilizing extensive landscapes will continue to face management challenges including changes in public land policy, anthropogenic development, climatic variability, invasive weeds, wildfire, water quality, and threatened and endangered species concerns. As an industry and a discipline we must continue to improve or ability to manage for “designed” landscapes that improve the economics of livestock production while maintaining or enhancing rangeland health and ecological function, thereby improving the long-term sustainability of grazing systems. [ABSTRACT FROM AUTHOR]

Although goat meat production could be an option for diversification in improved upland pastures in northern Spain, precise information on the optimal grazing management to enhance goat performance and maximize production per unit land area is lacking. The objective of this study was to compare the effects of 3 stocking rates, high stocking rate (HSR; 20 goats/ha), medium stocking rate (MSR; 15 goats/ ha), and low stocking rate (LSR; 10 goats/ha), on gastrointestinal (GI) nematode infections and productive responses of Cashmere goats grazing such pastures. Treatments were replicated twice on 6 paddocks sown with Lolium perenne and Trifolium repens and with a high presence of the native grass Agrostis capillaris. The experiment lasted 3 grazing seasons (from spring to autumn). Pastures were sampled for sward height and botanical and proximate composition. Body weight and BCS changes of goats were monitored and GI nematode infections were assessed by fecal egg counts (FEC). The established treatments resulted in lower mean sward height in the HSR than in the MSR and LSR (9.6, 11.5, and 14.4 cm, respectively; P < 0.001). Pasture botanical composition and nutritive quality did not differ between treatments. The mean FEC of does across the 3 grazing seasons were greater (P < 0.05) in the HSR than in the LSR. Trichostrongylus spp., Oesophagostomum columbianum, and Teladorsagia circumcincta were the most prevalent nematode species identified in coprocultures. Does showed more favorable (P < 0.001) BW and BCS changes in the LSR than in the MSR and HSR (-14, -30, and -52 g/d and -0.1, -0.3, and -0.7 BCS units [scale 1 to 5], respectively). Greater (P < 0.001) kids' BW gains were observed in the LSR and MSR (average 94 g/d) compared with the HSR (70 g/d). Inversely, kid output per unit land area was greater in the HSR than in the MSR and LSR (320, 258, and 192 kg·ha-1·yr-1, respectively; P < 0.001), whereas daily kids' BW gains per hectare were greater (P < 0.001) in the HSR and MSR (average 1.37 kg·d-1·ha-1) compared with the LSR (0.98 kg·d-1·ha-1). A medium stocking rate of 15 goats/ha could represent the best compromise between animal health, performance, and productivity per unit land area in this type of upland pastures, but stricter controls of parasite levels during the grazing season would be necessary to avoid production losses, unless alternative nutraceuticals are provided. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) fluxes and soil organic carbon (SOC) accumulation in grassland ecosystems are intimately linked to grazing management. This study assessed the carbon equivalent flux (Ceqflux) from 1) an irrigated, heavily stocked, lowdensity grazing system, 2) a nonirrigated, lightly stocked, high-density grazing system, and 3) a grazing- exclusion pasture site on the basis of the GHG emissions from pasture soils and enteric methane emissions from cows grazing different pasture treatments. Soil organic carbon and total soil nitrogen stocks were measured but not included in Ceqflux determination because of study duration and time needed to observe a change in soil composition. Light- and heavy-stocking systems had 36% and 43% greater Ceqflux than nongrazed pasture sites, respectively (P < 0.01). The largest contributor to increased Ceqflux from grazing systems was enteric CH4 emissions, which represented 15% and 32% of the overall emissions for lightly and heavily stocked grazing systems, respectively. Across years, grazing systems also had increased nitrous oxide (N2O; P < 0.01) and CH4 emissions from pasture soils (P < 0.01) compared with nongrazed pasture sites but, overall, minimally contributed to total emissions. Results indicate no clear difference in Ceqflux between the grazing systems studied when SOC change is not incorporated (P = 0.11). A greater stocking rate potentially increased total SOC stock (P = 0.02), the addition of SOC deeper into the soil horizon (P = 0.01), and soil OM content to 30 cm (P < 0.01). The incorporation of long-term annual carbon sequestration into the determination of Ceqflux could change results and possibly differentiate the grazing systems studied. [ABSTRACT FROM AUTHOR]

The objective was to compare the effects of tall fescue grazing systems utilizing either rotational grazing only or rotational grazing and spring and fall stockpiling on beef cow body condition and reproductive performance, calf pre-weaning performance, and forage characteristics. Over 2 years, multiparous, fall-calving cows (n = 360/year; BW = 600 ± 64 kg; gestation = 113 ± 8.5 d) were randomly assigned to 1 of 2 treatments (3 reps/treatment/year); 1) rotational grazing and spring and fall stockpile grazing (SP) and 2) rotational grazing only (CON). Treatments were initiated in late April and terminated in late December each year. Pastures were 48.4 ha/replicate. The CON pastures were divided into eight (6.05 ha) paddocks and cows rotated every 5 days. Twenty-five percent of SP pastures (12.1 ha) were stockpiled for initial 112 days with remaining 75% rotationally grazed (6 paddocks; rotated weekly). An additional 50% (24.2 ha) was stockpiled for 95 days starting early August. Stripgrazing was utilized when grazing stockpiled forage. Forage availability into new paddock was greater in SP than CON during grazing rounds 4, 5, and 6 (P = 0.01), coinciding with grazing of stockpiled forage. Grazing days were increased 24 days for SP versus CON (P = 0.01). Hay fed per cow was reduced in SP compared to CON (59 kg vs. 347 kg, respectively; P = 0.01). Cow BW did not differ at trial end (P = 0.13) however, BCS was greater for CON than SP (5.3 vs. 5.1, respectively; P = 0.01). No differences (P = 0.14) were observed in AI or overall pregnancy rate between treatments. There were no differences in calf birth or weaning BW (P = 0.30) between treatments. Overall, utilization of spring and fall stockpiling system had little impact on cow and calf performance but increased grazing days. [ABSTRACT FROM AUTHOR]

Pasture-fed beef cattle production has been often criticized as a source of greenhouse gas emissions. However, ruminants efficiently convert foods of low nutritional value to humans (e.g., pasture and by-products) into beef, a high-quality food. The present study aimed assessing the ratio between carbon emission per human-edible protein produced (HePp) of Nellore young bulls under three levels of beef cattle intensification systems: lenient, semi-intensive, and intensive. During backgrounding, all animals were raised in marandu palisadegrass pastures managed in continuous stocking with variable stocking rate and fertilized with 0, 75, and 150 kg N/ha, as ammonium nitrate (32% N) for lenient, semi-intensive, and intensive systems, respectively. During the finishing phase, bulls from lenient system remained in the pasture, while animals from semi-intensive and intensive systems were moved to a feedlot barn. The total carbon emission was represented by the total GHG emissions converted to CO2 equivalent (CO2e). Humanedible protein produced was calculated for each production phase and for the entire production system based on animal body protein minus the inedible fraction of empty body weight. Data were analyzed using PROC MIXED procedures of SAS. During the backgrounding phase, the ratio CO2e/kg HePp of semi-intensive did not differ from other systems; however, the intensive system presented the greatest ratio (P< 0.05). During the finishing phase, the ratio was greater for the more intensive systems (P< 0.05). For the entire period, the ratio was greater for the intensified systems (P< 0.05). Although the HePp of bulls from the intensified systems was greater than the lenient system (P< 0.05), the gain was insufficient to offset the CO2e production. Our results suggest that cattle ranching intensification acquired by improvements in grazing management is the most powerful tool to mitigate environmental impact of grazing systems. The authors acknowledge the São Paulo Research Foundation (FAPESP #2017/18750-7; #2018/26492-0). [ABSTRACT FROM AUTHOR]

The relationships among rangeland management practices and ecosystem on soil and nutrient processes are complex. Simulation models can provide valuable insight into this complexity to guide future research and management decisions for sustainable grazing systems. The objective of this analysis was to evaluate the combinations of grazing management (continuous vs. rotational), stocking rate (low, moderate, or high), and burning (none vs. annual spring burn) on soil erosion, nutrient losses, and carbon sequestration. Soil, weather, and forage species data were collected for 3 locations in the Central Great Plains (Konza Prairie Biological Station, Kansas; Agricultural Research Center-Hays, Kansas; Central Plains Experimental Range, Wyoming). These data were used to simulate combinations of rangeland management scenarios using the Agricultural Policy/Environmental eXtender (APEX) model. A stocker cattle operation was simulated at Hays, Kansas and Wyoming locations, and a cow-calf operation at Konza, Kansas location. Burning increased soil loss from water erosion regardless of stocking rate or grazing management. Rotational grazing increased soil loss at the Kansas locations, but decreased soil loss at Wyoming compared with continuous grazing. Stocking rate had little effect on nitrogen losses, but rotational grazing decreased nitrogen loss compared with continuous grazing. Greater stocking rates slightly decreased phosphorus losses with continuous grazing, but not rotational grazing. Burning decreased phosphorus losses with continuous grazing at Konza, but not the other locations. Greater stocking rates decreased the deposition of soil organic carbon especially with continuous grazing, and burning resulted in losses of soil organic carbon at Konza and Wyoming. In conclusion, rangeland management practices differentially affect nutrient processes among ecosystems such that a one-size-fits-all management scheme will not maximize retention of all nutrients in all ecosystems. [ABSTRACT FROM AUTHOR]

Remote sensing has opened doors for grazing management by allowing producers to monitor forage in a more efficient way. The objective of this study was to observe the relationship between the normalized vegetation index (NDVI) from images taken by an unmanned aerial vehicle (UAV) to nutritive value parameters. This project took place at the H. H. Leveck Animal Research Center located in Starkville, MS where 9, 2-hectare pastures planted in Marshall annual ryegrass (Lolium multiflorum) were utilized. Each 2-hectare pasture was subdivided into 0.20-hectare sections where forage samples were collected from 3, 1/4 of a meter quadrat every 14-days. Images were taken with UAV over a 76-day grazing period every 14-days. Images from the UAV were captured at 121.9 m above ground level using a DJI inspire 2 rotor wing fitted with a MicaSense RedEdge camera (MicaSense; Seattle, WA). Images were processed using Pix4D (Pix4D SA; Prilly, Switzerland) and analyzed in QGIS (QGIS; OSGeo; Finland). Raster calculator in QGIS was utilized to calculate NDVI values. Forage samples were analyzed using NIR for crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), relative forage quality (RFQ), and invitro dry matter digestibility (IVDMD) and correlated to NDVI values. Regression analysis was conducted in R (RStudio, PBC) using the package easynls (easynls-package) procedure within package ggplot2 (ggplot2-package). Regression models were obtained through a backward-elimination technique. Neutral detergent fiber (r² = 0.27) had the best correlated relationship to NDVI compared with CP (r² = 0.21), ADF (r² = 0.25), RFQ (r² = 0.18), and IVDMD (r² = 0.22). As NDVI values increased, CP, RFQ, and IVDMD increased while ADF and NDF decreased. There was a weak correlation between all nutritive value parameters and NDVI values. In conclusion, weak relationships indicate that NDVI values may not be the best predictor of nutritive value. [ABSTRACT FROM AUTHOR]

In a 3-yr study, 135 crossbred steers (330 ± 10 kg) were used in a randomized complete block design to evaluate corn dried distillers grains plus solubles (DDGS) fed to yearling steers as a substitute for forage and N fertilizer and its effect on N use efficiency in yearling steers grazing smooth bromegrass pastures. Steers were initially stocked at 6.8 animal unit months (AUM)/ha on nonfertilized smooth bromegrass pastures (CONT), at 9.9 AUM/ha on smooth bromegrass pastures fertilized with 90 kg of N/ha (FERT), or at 9.9 AUM/ha on nonfertilized smooth bromegrass pastures with 2.3 kg (DM) of DDGS supplemented daily per steer (SUPP). Paddock was the experimental unit, with 3 replications per treatment per year for 3 yr. Paddocks were strip-grazed, and put-and-take cattle were used to maintain similar grazing pressure among treatment paddocks during the 160-d grazing season. Steers consumed less forage (P < 0.01), but total N intake for SUPP was greater (P < 0.01) per steer and per hectare than for FERT, and both were greater (P < 0.01) than for CONT. Nitrogen retention for steers in the SUPP treatment was increased (P < 0.01) by 31% compared with N retention in the CONT and FERT treatments. Nitrogen retention per hectare for SUPP was 30 and 98% greater (P < 0.01) than N retention per hectare for FERT and CONT, respectively. Nitrogen excretion per steer and per hectare were also greater (P < 0.01) for SUPP than FERT, and both were increased (P < 0.01) compared with CONT. Animal N use efficiency was similar (P = 0.29) for steers in the CONT, FERT, and SUPP treatments. However, system-based N use improved (P < 0.01) by 144% for SUPP compared with FERT. The DDGS increased N intake and N excretion in yearling steers. However, because of improvements in BW gain and increases in stocking rate of pastures, DDGS can be a useful tool to increase the efficiency of N use in smooth bromegrass grazing systems. [ABSTRACT FROM AUTHOR]

A 2–yr production study was conducted to evaluate 3 systems of growing stocker calves under rotational stocking. One group of steers was stocked on pasture from early April to mid August (springstocked steers = SSS), and another group of steers was stocked from early July to late October (fall–stocked steers = FSS). Steers were stratified by BW (n = 72, BW=229±llkgforSSS;n=72,BW=248±18 kg for FSS) and randomly assigned to 1 of 3 treatments. The 3 treatments were 1) rotationally stocked only (control; CON), steers rotated to a new paddock as forage availability dropped below acceptable levels in the occupied paddock; 2) rotationally stocked with distillers grains (DIST); this was the same as CON except steers were supplemented with varying amounts of distillers dried grains with solubles (DDGS) based on forage nutritive value; and 3) rotationally stocked with round–bale silage (SIL); excess forage in spring was harvested and stored as round–bale silage and fed back as needed. Total BW gain/ha over the entire grazing season did not differ between DIST and SIL (P = 0.09) steers, but both were greater thall CON (P < 0.01). Total BW gain/ha for DIST, SIL, and CON was 459 (SEM = 11.5), 402 (SEM = 31.0), and 276 (SEM = 26.2) kg, respectively. For ADG, there was a group x year (P < 0.01) and group x treatment (P = 0.02) interaction. Steer ADG for SSS did not differ between SIL and DIST (P = 0.51), but was greater than the CON (P = 0.01). The ADG for SSS was 0.79 (SEM = 0.04), 0.81 (SEM = 0.05), and 0.62 (SEM = 0.05) kg for DIST, SIL, and CON, respectively. For the FSS, ADG for all 3 treatments was different (P = 0.02). The FSS ADG was 0.72 (SEM 0.03), 0.53 (SEM = 0.04), and 0.29 (SEM = 0.04) kg for DIST, SIL, and CON, respectively. The only treatment with equivalent (P = 0.07) ADG between early and late–stocked steers (SSS vs. FSS) was DIST. Adjusting the amount of DDGS supplemented to steers based on forage nutritive value resulted in consistent BW gains throughout the grazing study, whereas steers in the SIL and CON treatments gained less BW during the latter portion of the season. Controlling forage maturity by removal in the SIL treatment resulted in total BW gains/ha that were not different than the DIST treatment. [ABSTRACT FROM AUTHOR]

A 2–yr production study was conducted to evaluate 3 systems of growing stocker calves under rotational stocking. One group of steers was stocked on pasture from early April to mid August (springstocked steers = SSS), and another group of steers was stocked from early July to late October (fall–stocked steers = FSS). Steers were stratified by BW (n = 72, BW=229±llkgforSSS;n=72,BW=248±18 kg for FSS) and randomly assigned to 1 of 3 treatments. The 3 treatments were 1) rotationally stocked only (control; CON), steers rotated to a new paddock as forage availability dropped below acceptable levels in the occupied paddock; 2) rotationally stocked with distillers grains (DIST); this was the same as CON except steers were supplemented with varying amounts of distillers dried grains with solubles (DDGS) based on forage nutritive value; and 3) rotationally stocked with round–bale silage (SIL); excess forage in spring was harvested and stored as round–bale silage and fed back as needed. Total BW gain/ha over the entire grazing season did not differ between DIST and SIL (P = 0.09) steers, but both were greater thall CON (P < 0.01). Total BW gain/ha for DIST, SIL, and CON was 459 (SEM = 11.5), 402 (SEM = 31.0), and 276 (SEM = 26.2) kg, respectively. For ADG, there was a group x year (P < 0.01) and group x treatment (P = 0.02) interaction. Steer ADG for SSS did not differ between SIL and DIST (P = 0.51), but was greater than the CON (P = 0.01). The ADG for SSS was 0.79 (SEM = 0.04), 0.81 (SEM = 0.05), and 0.62 (SEM = 0.05) kg for DIST, SIL, and CON, respectively. For the FSS, ADG for all 3 treatments was different (P = 0.02). The FSS ADG was 0.72 (SEM 0.03), 0.53 (SEM = 0.04), and 0.29 (SEM = 0.04) kg for DIST, SIL, and CON, respectively. The only treatment with equivalent (P = 0.07) ADG between early and late–stocked steers (SSS vs. FSS) was DIST. Adjusting the amount of DDGS supplemented to steers based on forage nutritive value resulted in consistent BW gains throughout the grazing study, whereas steers in the SIL and CON treatments gained less BW during the latter portion of the season. Controlling forage maturity by removal in the SIL treatment resulted in total BW gains/ha that were not different than the DIST treatment. [ABSTRACT FROM AUTHOR]

Demographic history, current status, and efficiency of the mating strategy were analyzed using the pedigree of Pannon White (PW) rabbits born between 1992 and 2007. Potential accumulation of detrimental effects and loss of genetic diversity were also considered. Calculations and estimates were done most often for ral)bits born in 2007, whereas other reference populations (REFPOPXXXX) were specified explicitly. The pedigree contained 4,749 individuals and 580 founders, and its completeness was 82.1% up to 10 and 94.5% up to 5 generations, respectively. Generation intervals through different pathways averaged 1.2 yr. When adjusted to the pedigree completeness, the amount of inbreeding (Fi) of rabbits was comparable (5.54%) with that of other livestock populations, whereas the 10 (30) founders contributing the most to inbreeding explained a large part of the population inbreeding [i.e., 42.24% (73.18%)]. The ancestral inbreeding coefficient of REFPOP2004 (10.67%) was one-half that of REFPOP2007 (20.66%), showing its strong dependence on pedigree length. Family variance, inbreeding, and realized effective population size were 84.18 (REFPOP2006; this variable could not be calculated for the last year examined), 37.19, and 91.08, respectively. The effective numbers of ancestors, founders, and founder genomes were 48, 26, and 7.33, respectively. Although the circular mating scheme applied was generally effective, the large accumulated reduction in genetic variability indicates the need to revise and improve the current breeding strategy. [ABSTRACT FROM AUTHOR]

Meat has been important to human survival and personal enjoyment for thousands of years, and as societies become more affluent, the amount and quality of meat consumed increases. Ancient Egyptians are known to have consumed ground meat, whereas the Greeks and Romans enjoyed various types of sausages. Ground meat has been consumed throughout the world under various names and for several centuries. However, in recent years, microbial meat safety has become a major concern, and it appears that meat safety challenges will persist in future years. This paper provides a brief historical account of selected developments in microbiology, meat science, and safety, and associated industrial and regulatory highlights, and a brief overview of current and future food safety issues, concerns, and challenges. [ABSTRACT FROM AUTHOR]

Ergot alkaloids have been associated with vasoconstriction in grazing livestock affected by the fescue toxicosis syndrome. Previous in vitro investigations studying how ergot alkaloids caused vasoconstriction have shown that ergovaline has a distinct receptor affinity and sustained contractile response. A similar contractile response has not been noted for lysergic acid. The objectives of this study were to determine if repetitive in vitro exposure of bovine lateral saphenous vein to lysergic acid or ergovaline would result in an increasing contractile response and if a measurable bioaccumulation of the alkaloids in the vascular tissue occurs over time. Segments of vein were surgically biopsied from healthy, Angus × Brangus cross-bred, fescue-naïve yearling heifers (n = 16) or collected from healthy mixed breed and sex cattle immediately after slaughter (n = 12) at a local abattoir. Veins were trimmed of excess fat and connective tissue, sliced into cross-sections, and suspended in a myograph chamber containing 5 mL of oxygenated Krebs-Henseleit buffer (95% O2/5% CO2 pH = 7.4; 37°C). Contractile responses to repetitive additions of ergovaline (1 × 10-9 and 1 × 10-4 M) and lysergic acid (1 × 10-5 and 1 × 10-4M) were evaluated using the biopsied veins. For the bioaccumulation experiments, veins collected at the abattoir underwent repetitive additions of 1 × 10-7 M ergovaline and 1 × 10-5 M lysergic acid and the segments were removed after every 2 additions and media rinses for alkaloid quantification via HPLC/mass spectrometry. Contractile data were normalized as a percentage of contractile response induced by a reference dose of norepinephrine (1 × 10-4 M). Repetitive additions of 1 × 10-9 M ergovaline and 1 × 10-5 and 1 × 10-9 M lysergic acid resulted in contractile response with a negative slope (P < 0.02). In contrast, repetitive addition of 1 × 10-7 M ergovaline resulted in a contractile response that increased with each addition (P < 0.01). Lysergic acid and ergovaline were detected at all 4 exposure levels (2× to 8×), but only the 1 × 10-7 M ergovaline treatment resulted in increased tissue content as the number of exposures increased (P. < 0.05). These data indicate that ergovaline, but not lysergic acid, bioaccumulates with repetitive exposure in vitro. These results suggest that ergovaline may have a greater potential for inducing toxicosis in grazing animals than lysergic acid because of its potential to bioaccumulate at the cellular site of action. [ABSTRACT FROM AUTHOR]

A total of 295 goats from 4 breeds (Alpine, n = 74; Angora, n = 75; Boer-cross, n = 73; Spanish, n = 73) were used to assess the retention of 3 types of electronic ruminal boluses (B1, 20 g, n = 95; B2, 75 g, n = 100; and B3, 82 g, n = 100) according to breed and feeding conditions. Time for bolus administration, reading with a handheld reader, and animal data recording (goat identification, breed, and bolus type) were registered. Each goat was also identified with 1 flag-button plastic ear tag (4.6 g, 51 × 41 mm). Retention of boluses and ear tags was regularly monitored for 1 yr. Ruminal fluid in 5 goats from each breed and management group was obtained with an oro-ruminal probe at 2 h after feeding. Ruminal pH was measured at 24 h and at wk 1, 2, 3, and 4 and used as an indicator of feeding conditions on rumen environment. Time for bolus administration differed by bolus type (B1, 14 ± 2 s; B2, 24 ± 2 s; B3, 27 ± 2 s; P < 0.05) and goat breed (Alpine, 34 ± 3 s; Angora, 17 ± 2 s; Boer-cross, 16 ± 1 s; Spanish, 19 ± 2 5; P < 0.05), although differences were due to greater times for B2 and B3 in Alpine goats. Time for bolus administration averaged 22 ± 1 s, and overall time for bolusing, reading, and data typing was 49 ± 1 s on average. Ruminal pH differed according to breed and feeding management (lactating Alpine, 6.50 ± 0.07; yearling Alpine, 6.73 ± 0.07; Angora, 6.34 ± 0.06; Boer-cross, 6.62 ± 0.04; Spanish, 6.32 ± 0.08; P < 0.05), but no early bolus losses occurred; rumen pH did not differ according to bolus type (B1, 6.45 ± 0.05; B2, 6.39 ± 0.07; B3, 6.49 ± 0.05; P> 0.05). At 6 mo, electronic boluses showed greater retention than ear tags (99.7 vs. 97.2%; P < 0.05). At 12 mo, bolus retention was 96.3, 100, and 97.8% for B1, B2, and B3, respectively, not differing between B1 and B3 (P = 0.562). No effect of breed and bolus type on bolus retention was detected. No goat losing, at the same time, both bolus and ear tag was observed. Ear tag retention (91.7%) was less (P < 0.05) than all types of bolus (98.1%) on average. Ear tag retention in Boer-cross (98.6%) and Alpine (96.9%) goats was greater (P < 0.05) than in Spanish (88.7%) and Angora (82.9%) and tended to differ (P = 0.095) between Spanish and Alpine. In conclusion, unlike flag-button visual ear tags and mini-boluses used here, properly designed boluses (e.g., standard bolus) met International Committee for Animal Recording and National Animal Identification System retention requirements for goat identification under US conditions and are recommended in practice. [ABSTRACT FROM AUTHOR]

A study was conducted to determine if sampling rumen contents via a ruminal cannula or oral lavage tube would yield similar denaturing gradient gel electrophoresis profiles of the bacterial community. Two species of ruminally cannulated animals were used for this study (cattle, n = 2; sheep, n = 3). All animals were allowed ad libitum access to feed. Cattle were fed baled unprocessed sorghum-sudan hay (12% CP, 68% NDF; DM basis), whereas sheep were maintained on chopped alfalfa (18% CP, 40% NDF; DM basis). Ruminal fluid was collected (approximately 20 mL) once per week for 3 wk from each animal using a poly tube equipped with a suction strainer with a hand-held suction pump through the rumen cannula or oral cavity. The denaturing gradient gel electrophoresis analysis demonstrates that yield of bacterial diversity was not different between the 2 sampling methods (P = 0.73). When samples were grouped according to band pattern similarity, groups were most stable according to individual animal and species rather than sampling method. Total VFA and molar proportions of individual VFA did not differ by sampling method (P > 0.40). Additionally, rumen ammonia concentrations were similar for both sampling methods (19.3 vs. 19.1 mM ± 8.0 for cannula vs. lavage, respectively; P = 0.98). These data indicate that rumen samples collected via oral lavage or rumen cannula yield similar results. This knowledge will allow sample collection from a greater population of animals and an ability to maintain the value of research livestock that can be lost due to the surgical implantation of a ruminal cannula. [ABSTRACT FROM AUTHOR]

Sustainability research is complex and involves the evaluation of tradeoffs. Environmental, economic, and social aspects should ideally be considered. Even when one only pillar of sustainability is evaluated, results should be assessed within the broader context of overall sustainability. Environmental impacts from forage and livestock systems, as well as confined animal feeding operations, can be positive and negative, depending on the type of operation, environmental setting, weather episodes, and management conditions. These systems also have associated social and economic impacts. As in all agricultural management systems, there are likely to be hotspots of damage due to a particular management style combined with the right soil, landscape, and climatic conditions. Widespread, positive benefits of pasture-based management are possible when forage resources are utilized ideally with best grazing management principles leading to enhanced soil organic carbon storage, high water infiltration, efficient nutrient cycling, and minimal water and nutrient runoff into nearby water bodies. Research to quantify the environmental impacts of livestock management systems can be designed in detail on research stations to understand the direct implications of management differences on plant biomass production that captures atmospheric CO2, on carbon stored in soil organic matter, and on greenhouse gas emissions from ruminant livestock fed controlled diets. On-farm research is also valuable to characterize the impacts of a particular style of management across a diversity of environments using a system-level approach integrated across the farm. Communication strategies engaging major stakeholders from the livestock industry are key to deliver a consistent message to the general public. Perceived benefits, challenges, and opportunities must be science based, seeking opportunities to reduce negative impacts, and enhancing the positive ones. Messaging to the lay audience about environmental impacts can be focused on solutions from positive benefits or problems from negative effects, but should also address economic and social components. [ABSTRACT FROM AUTHOR]