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Data from USDA ARS Central Plains Experimental Range (CPER) near Nunn, CO: Cattle weight gains managed with light, moderate and heavy grazing intensities

LTGI Herd on Central Plains Experimental Range, near Nunn, CO

The USDA-Agricultural Research Service Central Plains Experimental Range (CPER) is a Long-Term Agroecosystem Research (LTAR) network site located ~20 km northeast of Nunn, in north-central Colorado, USA. In 1939, scientists established the Long-term Grazing Intensity study (LTGI) with four replications of light, moderate, and heavy grazing. Each replication had three 129.5 ha pastures with the grazing intensity treatment randomly assigned. Today, one replication remains. Light grazing occurs in pasture 23W (9.3 Animal Unit Days (AUD)/ha, targeted for 20% utilization of peak growing-season biomass), moderate grazing in pasture 15E (12.5 AUD/ha, 40% utilization), and heavy grazing in pasture 23E (18.6 AUD/ha, 60% utilization). British- and continental-breed yearling cattle graze the pastures season-long from mid-May to October except when forage limitations shorten the grazing season. Individual raw data on cattle entry and exit weights, as well as weights every 28-days during the grazing season are available from 2000 to 2019. Cattle entry and exit weights are included in this dataset. Weight outliers (± 2 SD) are flagged for calculating summary statistics or performing statistical analysis.

Release Date
Spatial / Geographical Coverage Area
POLYGON ((-104.74299417576 40.826648795134, -104.75315245788 40.826698002219, -104.7531286736 40.823567497273, -104.75308795659 40.81541020461, -104.75308643986 40.812450903073, -104.74408743733 40.812480841203, -104.74301211022 40.826419118394, -104.74300158176 40.826554222408, -104.74299417576 40.826648795134))
POLYGON ((-104.75315245788 40.826698002219, -104.75315395551 40.826977268868, -104.75323672081 40.841206350945, -104.753228788 40.841296418733, -104.76309583918 40.841211253448, -104.76332088774 40.84118556917, -104.76288095375 40.832857695908, -104.76272903898 40.82774956763, -104.76272507332 40.827614432007, -104.76270223152 40.826848662653, -104.7627114273 40.826722562577, -104.76248956791 40.826726610311, -104.7606714239 40.826713844579, -104.75585544592 40.826703753794, -104.75315245788 40.826698002219))
POLYGON ((-104.73416457694 40.82663329251, -104.74299417576 40.826648795134, -104.74300158176 40.826554222408, -104.74301211022 40.826419118394, -104.74408743733 40.812480841203, -104.73419250487 40.812489999889, -104.73417227135 40.821921864609, -104.73417239075 40.821984924411, -104.7341626591 40.82655671587, -104.73416457694 40.82663329251))
Ag Data Commons
Spatial / Geographical Coverage Location
The USDA-Agricultural Research Service Central Plains Experimental Range (CPER) is a Long-Term Agroecosystem Research (LTAR) network site located ~20 km northeast of Nunn, in north-central Colorado, USA (40°50 N, 104°43 W, 1645 m above sea level). Mean annual precipitation (1939–2018) is 340 mm, with 43% of this occurring from April through June and 37% from July through September. Major soils on the study pastures are Ascalon fine sandy loam (fine-loamy mixed mesic Aridic Argiustoll) and Renohill fine sandy loam (fine montmorillonitic mesic Ustollic Haplargid). The main ecological site in the study pastures is Loamy Plains (Site ID: R067BY002CO; data available online). The perennial C4 shortgrass blue grama (Bouteloua gracilis [Willd. ex Kunth] Lag ex Griffiths) is the dominant species and increases as grazing intensity increases. Conversely, the perennial C3 mid-height grasses western wheatgrass (Pascopyrum smithii [Rydb] A. Love) and needle-and-thread (Hesperostipa comata [Trin. & Rupr.] Barkworth ssp. comata) decrease with increasing grazing intensity. Other key plant species include needleleaf sedge (Carex duriuscula C.A. Mey), an important perennial C3 graminoid, scarlet globemallow (Sphaeralcea coccinea [Nutt.] Rydb.), the primary forb, and plains pricklypear cactus (Opuntia polyacantha Haw).
Temporal Coverage
January 1, 2000 to December 31, 2019
Data Dictionary
Contact Name
Derner, Justin
Contact Email
Public Access Level
Program Code
005:040 - Department of Agriculture - National Research
Bureau Code
005:18 - Agricultural Research Service