Livestock response to multispecies and deferred-rotation grazing on forested rangeland

Abstract

Performance of cow-calf (Bos taurus) and ewe-lamb (Ovisaries) units was compared under multispecies versus single-species grazing and deferred-rotation versus continuous stocking during a 10-year grazing trial. Treatments were arranged in a 3 species (cattle, sheep, or both species) by 2 grazing method (deferred rotation or continuous) factorial using a randomized-complete block design with 2 blocks. All animals were individually weighed at initiation, mid-point, and termination of each grazing season. Livestock species and grazing method did not interact for any dependent variable (P>0.05). Average daily gain (ADG) was greater (P<0.05) when calves were alone than when mixed with sheep (1.04 vs 1.01 kg day-1, respectively), but ADG of lambs was greater (P<0.05) when mixed with cattle than alone (0.25 vs 0.23 kg day-1, respectively). Cow and ewe ADG were unaffected (P>0.05) by animal species mixture. Production of progeny (gain of calves and lambs) and total production (gain of progeny and dams) per ha was greater (P<0.05) using sheep or mixed species than cattle (17.8, 17.8, and 11.2 kg ha-1 respectively, for progeny, and 22.4, 24.5, and 17.6 kg ha-1 respectively, for total). Calves grew faster (P<0.05) under continuous than deferred-rotation grazing (1.04 vs 1.01 kg day-1). Ewes gained more rapidly (P<0.05) during the second half of the grazing season under deferred-rotation than continuous grazing (0.049 vs 0.023 kg day-1). Multispecies or sheep grazing appeared more appropriate than cattle for this environment. Deferred-rotation grazing appeared superior for sheep performance, but continuous grazing allowed greater calf performance.