An Ecological and Economic Risk Avoidance Drought Management Decision Support System

Ecologists have long recognized the fundamental impacts of drought on rangeland structure and function. Simulation models have been developed to increase our understanding of these impacts as they relate to forage production, particularly for predictive purposes. Although the capacity of these models to accurately predict quantity and quality of forage produced under varying climatic conditions is often quite good, their ability to serve as an effective and proactive drought management decision support system is often limited. This is in large part because their complexity impedes their use by on-the-ground managers. The objective of this research was to develop a very simple and user-friendly drought management decision support system for rangeland managers in the Northern Great Plains of North America

Evaluation of Beef Cattle Operations Utilizing Different Seasons of Calving, Weaning Strategies, Postweaning Management, and Retained Ownership

Data from a 3-yr study in Montana were utilized to evaluate impacts of season of calving, weaning strategy, and retained ownership of steer calves on enterprise profitability. Calving seasons were late winter (LW), early spring (ES), or late spring (LS). Each season had 2 weaning times: 190 (LW190, ES190) or 240 (LW240, ES240) d for LW and ES, and 140 (LS140) or 190 (LS190) d for LS. Backgrounding options included shipping steers to Oklahoma (OK1), or backgrounding in Montana to a constant age (MT2) or weight (MT3). Steers from OK1 and MT2 were finished in Oklahoma in confinement or via self-feeders on pasture and harvested in Texas. Steers in MT3 were finished in Montana in confinement and harvested in Colorado. Performance of each system was modeled based on actual animal performance, market prices, and variable input costs. When calves were sold at weaning, gross margins per cow were greatest for LS190 (P \u3c 0.05) and lowest for LW240. During backgrounding, costs of gain were similar among cow-calf systems, and gross margins per steer were greatest for LS140 (P \u3c 0.05), but not different among backgrounding systems. During finishing, costs of gain were greatest for steers from MT2 due to transportation costs to Oklahoma (P \u3c 0.05), and gross margin per steer favored MT3 (P \u3c 0.05). Gross margin for a ranch with a fixed land base did not differ among systems if calves were sold at weaning, but was greatest for LS systems after backgrounding or finishing (P \u3c 0.05)

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Relative Annual Broomweed Abundance as Related to Selected Climatic Factors

Regression models were developed to predict relative abundance of annual broomweeds on a Texas rangeland as a function of selected climatic factors. Based on 16 years' data, above-average precipitation in May and below-average daily maximum temperatures in April were the principal climatic factors most closely associated with heavy infestations of annual broomweeds for any given year (R2 = 0.902). Similar models developed from bimonthly and trimonthly averages were less precise than monthly averages for predicting relative abundance of annual broomweed.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Japanese Brome Impacts on Western Wheatgrass in Northern Great Plains Rangelands: An Update

Japanese brome (Bromus japonicas Thunb.) is an annual grass that has invaded thousands of hectares of Northern Great Plains rangelands. We studied the effect of Japanese brome on the current year\u27s increase in biomass in a plant community in the Northern Great Plains dominated by western wheatgrass [Pascopyrum smithii Rydb. (Love)]. In our experiment, brome seedlings were either removed or left in place in replicated l-m2 plots. Above-ground biomass of western wheatgrass increased (891 to 1,095 kg ha-1 ) with the removal of Japanese brome. However, total above-ground biomass decreased (1,873 to 1,334 kg ha-1) when brome was reduced in early spring (708 to 12 kg ha-1). Increased biomass of western wheatgrass resulted from increases in the density of tillers and not in the weight of each tiller. Since the effect of removing brome did not vary among the combinations of site and year, similar outcomes can be expected over a wide array of environmental conditions, such as among years with variable April to late-June or mid-July precipitation or stands with varying percents of brome and western wheatgrass. Thus, we conclude that the presence of annual Japanese brome reduces the biomass of important grasses in the Northern Great Plains

The Role of Livestock and Other Herbivores in Improving Rangeland Vegetation

This material was digitized as part of a cooperative project between the Society for Range Management, the National Agricultural Library, and the University of Arizona Libraries.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Social Values in the Assessment of Livestock Grazing in the Great Plains

We examined the sustainability of the livestock grazing industry in the Great Plains of North America relative to ecological processes, economic viability, and social acceptance. We conclude from the review that livestock grazing is an appropriate use of Great Plains grasslands and, when properly managed, ecologically sustainable. However, we also present evidence that the Great Plains grazing industry is not always economically sustainable or socially acceptable. We attribute this anomaly in large part to the consuming public\u27s general lack of understanding and appreciation for the ecological linkages between current livestock grazing tactics and the evolutionary history of the Great Plains. A contributing factor to this problem is the scientific community\u27s interjection of personal biases and value systems when interpreting ecological response patterns to varying forms of land use. We present evidence in support of this hypothesis by comparing statements and supporting literature citations from three recently published literature reviews addressing the ecological impacts of livestock grazing on North American rangelands

Credibility and the Business of Range Professionals

This material was digitized as part of a cooperative project between the Society for Range Management, the National Agricultural Library, and the University of Arizona Libraries.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Livestock Management During Drought in the Northern Great Plains. I. A Practical Predictor of Annual Forage Production

This research addressed the hypothesis that spring precipitation data can be used to detect agricultural drought early in the growing season. The Rangetek range model was used to simulate yearly forage data based on historical precipitation and temperature records from the USDA-ARS Fort Keogh Livestock and Range Research Laboratory (Miles City, MT) and the Agriculture and Agri-Food Canada Manyberries Substation (Lethbridge, AB, Canada). Monthly total precipitation and monthly average maximum and minimum temperatures were used to develop regression equations predicting growing season forage production at the Fort Keogh Laboratory and Manyberries Substation. At Fort Keogh Laboratory, a combination of fall (October and November) and spring (April and May) precipitation were predictors of simulated forage yield index (P \u3c 0.01, R2 = 0.84). At Manyberries Substation, April and May precipitation were predictors of simulated forage yield index (P \u3c 0.01, R2 = 0.44). Using the actual forage data from Manyberries Substation yielded similar results, in that April, May, and June were predictors of forage production (P \u3c 0.01, R2 = 0.50). Although the regression equation for actual forage production data from Manyberries Substation did indicate that July precipitation was a significant predictor, adding July precipitation did not increase the ability of the equation to detect reduced forage production. These results imply that annual forage production can be estimated with considerable confidence by July 1 and that forage produced by early July is a good indicator of total growing season forage production. Early season detection of drought effects on forage production provides much-needed flexibility in devising management alternatives to minimize the negative impacts of drought on rangelands and beef enterprises