Diet selection of bonded and non-bonded free-ranging sheep and cattle

Compared with monospecies stocking, numerous studies substantiate that multispecies stocking can efficiently increase use within and among the mosaic pattern of rangeland plant life forms. However, multispecies stocking may fail to bring anticipitated biological and financial results because of severe small ruminant losses, often because of coyote ( Canis latrans) predation. Previously published data have demonstrated that when young lambs are bonded to cattle, they will follow cattle under free-ranging conditions. This close association under free-ranging conditions has been shown to reduce coyote predation on lambs. However, in addition to protection, lambs that stay with cattle may have their diet selection influenced. Differences between cattle and sheep diets were estimated using microhistological analysis of heifer and lamb feces. The data indicated differences between pastures, animal species, and bonded and non-bonded lamb diets. Lambs bonded to cattle grazed 7% more grass, 5% fewer forbs and 4% fewer shrubs between April and June than non-bonded lambs. Cattle diets were not influenced by either bonded or non-bonded lambs grazing in the same pasture and averaged 57% grass, 35% forbs and 8% shrubs. In contrast, bonded sheep diets averaged 35% grass, 59% forbs and 5% shrubs. The relatively large differences between heifer and lamb diets, and the relatively small differences between bonded and non-bonded lamb diets, do not negatively impact the potential benefits to be gained from multispecies stocking using bonded sheep. Managing bonded sheep with cattle under free-ranging conditions may result in more uniform spatial use of the vegetation than would occur if either species were managed alone.