Date of this Version
Agriculture, Ecosystems and Environment 183 (2014) 110–117; http://dx.doi.org/10.1016/j.agee.2013.10.030
In the face of an increasingly variable climate, long-term cattle weight gain datasets are rare, yet invalu-able, for determining site-specific influences of seasonal weather patterns on cattle production. Here,we present a long-term (1936–2005) yearling Hereford steer dataset collected at the Northern GreatPlains Research Laboratory (NPGRL) near Mandan, ND, USA. Data were analyzed using weighted AICcmodel averaging to examine the effects of spring (April–June) and summer (July–September) temper-ature and precipitation, as well as prior growing season (prior April–September) and prior fall/winter(prior October–March) precipitation on cattle production (kg/ha) under light (37.4 ± 5.3 SD Animal UnitDays [AUD]/ha across all study years) and heavy (91.6 ± 22.2 SD AUD/ha) stocking rates. Because Ken-tucky bluegrass (Poa pratensis L.) invaded the grassland at NPGRL in the early 1980s, we modeled cattleproduction separately for pre- (1936–1983) and post-invasion (1986–2005) years to determine if theplant community shift influenced sensitivity to seasonal weather patterns. Cattle production under heavystocking was more sensitive to seasonal weather variability than under light stocking during both pre-and post-invasion years. Interestingly, the magnitude and robustness of coefficients changed between thepre- and post-invasion years, with seasonal weather patterns explaining more cattle production variationduring the post-invasion years. Though cattle sensitivity to seasonal weather patterns differed betweenlight and heavy stocking for both pre- and post-invasion years, invasion status did change cattle responseto weather. For example, cattle production in P. pratensis invaded pastures was more heavily influencedby cool, wet springs and wet prior grazing seasons than was production in un-invaded pastures. Forcattle stocked heavily in native pastures, wet winters more strongly increased cattle production than ininvaded pastures.