Temperature and Precipitation Affect Steer Weight Gains Differentially by Stocking Rate in Northern Mixed-Grass Prairie

Abstract

Cattle weight gain responses to seasonal weather variability are difficult to predict for rangelands because few long-term (.20 yr) studies have been conducted. However, an increased understanding of temperature and precipitation influences on cattle weight gains is needed to optimize stocking rates and reduce enterprise risk associated with climatic variability. Yearling steer weight gain data collected at the USDA-ARS High Plains Grasslands Research Station at light, moderate, and heavy stocking rates for 30 years were used to examine the effects of spring (April-June) and summer (July-September) temperature and precipitation, as well as prior-growing-season (prior April-September) and fall/winter (October-March) precipitation, on beef production (kg Á ha À1 ). At heavier stocking rates, steer production was more sensitive to seasonal weather variations. A novel finding was that temperature (relatively cool springs and warm summers) played a large predictive role on beef production. At heavier stocking rates, beef production was highest during years with cool, wet springs and warm, wet summers, corresponding to optimum growth conditions for this mixed C 3 -C 4 plant community. The novelty and utility of these findings may increase the efficacy of stocking rate decision support tools. The parsimonious model structure presented here includes three-month seasonal clusters that are forecasted and freely available from the US National Oceanic and Atmospheric Administration up to a year in advance. These seasonal weather forecasts can provide ranchers with an increased predictive capacity to adjust stocking rates (in advance of the grazing season) according to predicted seasonal weather conditions, thereby reducing enterprise risk.

Modeling weather and stocking rate effects on forage and steer production in northern mixed-grass prairie

“…Additionally, livestock weight gains were more sensitive to seasonal weather influences as SR increased (Reeves et al, 2013b(Reeves et al, , 2014. These results can be used by land managers to adjust SR levels to seasonal weather variability.…”

“…The CV values for PSC (0.29-0.37), Maint (0.21-0.20) and TotTDN (0.18-0.28) changed less with SR compared to the CV change of SWG. This result indicated that the quadratic response of TotTDN and linear response of Maint to SR resulted in high yearly variability of SWG at high SR levels, which explained the higher sensitivity of SWG to seasonal weather variations under higher SR levels (Reeves et al, 2013b(Reeves et al, , 2014. Fig.…”

“…(41°11 0 N, 104°53 0 W) (Hart et al, 1988;Manley et al, 1997;Derner and Hart, 2007;Derner et al, 2008b;Reeves et al, 2013b). Mean annual precipitation at the site is 381 mm with a peak in May and June.…”

“…During the grazing period of 1982-2012, peak standing crop (PSC) was not measured in 2000 for the three SR treatments, and was measured starting in 1991 for the low SR treatment. Detailed information on the experiment can be found in Derner and Hart (2007), Derner et al (2008b) and Reeves et al (2013b).…”

Grazing Management, Season, and Drought Contributions to Near-Surface Soil Property Dynamics in Semiarid Rangeland

“…The Treatments evaluated in the study included two permanent vegetation pastures and one seeded forage pasture, each of which belong to a network of long-term grazing studies investigating grazing management effects on animal performance and plant species composition and production (Reeves et al 2013). The permanent pastures included a moderately grazed pasture (MGP) and heavily grazed pasture (HGP), both established in 1916 on native rangeland and managed without the application of tillage, fertilizer, herbicides, or fire and Kentucky bluegrass (30% of the species composition) while the remainder of the species were similar to MGP.…”