Influence of grazing cattle and sheep together and separately on animal performance and forage quality.

Cattle and sheep grazed together and separately from April to October during 3 yr. Initial forage composition was 29% Kentucky bluegrass (Poa pratensis L.), 11% white clover (Trifolium repens L.), and 60% weeds. There were six Angus cow-calf pairs or six ewes (1/2 Dorset x 1/4 Finn x 1/4 Rambouillet) with 11 lambs per each of three pasture replications for single animal species. Six cow-calf pairs plus six ewes and 11 lambs grazed in each of three replications of the mixed animal species treatment. There were approximately one cow and calf or five ewes with lambs per .44 ha. Lambs were weaned at 41 kg or by September 1. Calves were weaned approximately October 10. Lamb daily gain (.23 kg/d), total gain (23 kg), and weaning weights (43 kg) were greater (P < .01) and target weaning weights were reached 14 d earlier in the grazing season when both animal species grazed together than when lambs were in pastures with sheep alone (.18 kg/d, 19 and 38 kg, respectively). Calf gains were not influenced by treatment. Grazing pressure increased throughout the grazing season for cattle alone, peaked in midsummer, and then decreased by autumn for sheep alone, whereas grazing pressure initially increased then remained relatively constant with mixed-species grazing. Forage quality in pastures where sheep grazed alone was lower (P < .05) than in pastures where cattle grazed alone until lambs were weaned in late summer, whereas forage quality with mixed-species grazing was generally intermediate. Mixed grazing resulted in earlier weaning and increased lamb performance and BW of ewes, but not in increased animal production per hectare.