Estell R.E.,Research Animal Scientist |
Havstad K.M.,Supervisory Scientist |
Cibils A.F.,Research Animal Scientist |
Anderson D.M.,Jornada Experimental Range |
Schrader T.S.,New Mexico State University
Rangelands | Year: 2014
On the Ground Loss of grasslands to shrublands continues. Demand for livestock products is expected to continue to grow. Increased demand for red meat may stimulate rangeland livestock production. Methods for increasing shrub use are needed to meet increasing forage demands. © 2014 The Society for Range Management.
Reeves J.L.,Research Ecologist |
Derner J.D.,U.S. Department of Agriculture |
Sanderson M.A.,Research Ecologist |
Kronberg S.L.,Research Animal Scientist |
And 5 more authors.
Rangelands | Year: 2015
On the Ground Ranching is a challenging and sometimes risky business, with cattle production (and associated enterprise income) largely being dependent on seasonal weather patterns and corresponding forage production. To help reduce this risk, the USDA-Agricultural Research Service performed a multistate study of seasonal weather effects on cattle production across the Northern Great Plains (Wyoming, North Dakota, and Montana). Cool, wet springs and longer, cooler growing seasons increased cattle production across the Northern Great Plains. Knowledge of these seasonal weather influences on cattle production is important for management decision making, but practical application of this knowledge remains problematic. Increased enterprise flexibility to deal with variable forage production can be achieved by using seasonal weather forecasts, as well as reducing base cow-calf herd numbers to less than 100% of typical ranch carrying capacity. Yearlings or seasonal contract grazing can then be used to increase grazing to use additional forage in good years. Recently launched USDA Regional Climate Hubs will deliver science-based knowledge, practical information, management and conservation strategies, and decision tools to ranchers that will help them adapt to weather variability and changing climatic conditions. © 2015 The Society for Range Management.
Cortus E.L.,Box 2120 |
Mamun M.R.A.,South Dakota State University |
Spiehs M.J.,Research Animal Scientist |
Ayadi F.Y.,Iowa State University |
And 6 more authors.
Transactions of the ASABE | Year: 2015
In conjunction with an emission monitoring study, long-term airflow and environmental data were collected from select pens in each of four regional producer owned and operated mono-slope beef cattle facilities in the Northern Great Plains. The barns were oriented east-west, with approximate depths of 30 m in the north-south dimension, 82 to 333 m widths in the east-west dimension, and south and north wall eave heights of 8 and 5 m, respectively. The north wall curtain openings were adjusted by the producers seasonally or daily, and classified as open (>1.5 m, mean SD = 2.1 m 0.1 m) or closed (<1.5 m, mean SD = 0.6 m 0.2 m). The temperature, relative humidity, and air velocity through the north and south wall openings were monitored at a fixed height near the center of the openings. On-site weather towers provided corresponding ambient temperature, relative humidity, and air velocity and direction data. The airflow was calculated as the product of the air velocity and opening area. The hourly mean airflows for the north and south wall openings were modeled as functions of perpendicular (to the barn opening) ambient air velocity (10 m height) and curtain opening. Theoretical airflows using the wind pressure coefficient method were also calculated. Based on comparisons between monitoring locations within an opening, north and south wall opening airflows, and measured versus theoretical values, greater confidence was given to airflow measurements for southerly airflow and open conditions. Airflow measurements for northerly flow and closed conditions were low compared to theoretical values. The uncertainties associated with the monitoring method are discussed, and the north wall opening airflow was deemed a reasonable measurement of airflow through the barn (i.e., for emission calculation purposes) for open and closed conditions. With a 5 m s-1 south wind, there were approximately 10 to 70 air changes per hour (ACH) for closed conditions in the four barns, and 160 ACH with open curtains. The average relationships between airflow through the pen volume and ambient wind velocity were 7 and 33 ACH (m s-1)-1 for closed and open conditions, respectively. These data assist producers in management decisions, and are required for aerial pollutant estimation for this type of beef cattle facility in the Northern Great Plains. ©2015 American Society of Agricultural and Biological Engineers..