Forage Growth and Steer Performance on Kentucky Bluegrass vs. Sequentially Grazed Kentucky Bluegrass-Switchgrass

Abstract

In the north central USA, Kentucky bluegrass (Poa pratensis L.) pastures often become semi-dormant with low forage supply in summer. The objective of this study was to determine the effectiveness of a cool-warm-cool season pasture system for improving animal performance in Wisconsin compared with season-long stocking of Kentucky bluegrass pasture. The coolwarm-cool season pasture system consisted of Kentucky bluegrass in the spring and fall with «Blackwell» switchgrass (Panicum virgatum L.) over summer. The study was conducted in central Wisconsin in 1990 and 1991. The cool-season graft pastures were on a soil predominantly Roscommon muck (mixed, frigid Mallic Psammaquents) having 3% or less slope. The warm-season grass pastures were on a soil predominantly Newsom loamy sand (mixed, frigid Humaqueptic Psammaquent) with no slope and Okee loamy sand (loamy, mixed, mesic Arenic Hapludalf) with 2 to 6% slope. Experimental animals were Hereford×Angus×Charolais beef steers (Bos taurus) weighing approximately 550 Ib at the initiation of the trial. There was no difference between the two grazing systems for seasonlong average daily gain (mean of 1.3 Ib/d). Gain per acre was also similar for the sequential grazing system and the continuous Kentucky bluegrass pasture (mean of 92 Ib/acre). In this experiment, no summer decline in forage production or beef steer performance occurred on season-long Kentucky bluegrass pasture. Sequential grazing of cool-warm-cool season grass pasture did not show any advantage over season-long Kentucky bluegrass pasture for increasing beef gain per acre or animal performance in central Wisconsin