Can Cattle and Sheep Co-Exist?Written by Scott Lake, Jeff Beck and Rachel Mealor
By UW Extension Specialists Scott Lake, Jeff Beck and Rachel Mealor
Multispecies grazing refers to the management practice of allowing more than one species of large herbivore with different forage preferences (grasses, forbs, shrubs, etc.) to graze a common forage resource.
Multispecies grazing is not a new phenomenon; in fact, quite the contrary. Evidence of multispecies grazing can be detected as far back as Old Testament days of the Bible, where occurrences of the words cattle and sheep appear together over 19 times. In addition, using multispecies grazing as a management tool has been advocated since the inception of range sciences. However, during the development of the unsettled and unfenced West, the perception was born that cattle and sheep are incompatible, likely due to an economic appraisal that cattle and sheep compete for limited forage resources.
The fundamental principles of proper grazing management include control of the intensity of grazing (stocking rate), timing of grazing, kind and class of herbivore and distribution of grazing.
Multispecies grazing leads to uniform utilization of forage resources, rather than the preferred forage of a single species. Further, multispecies grazing increases the efficiency of grazed forages and overall production on rangelands. The principle that favors multispecies grazing is that intraspecies (between individuals of the same species) competition is always greater than interspecies (between different species) competition. This relationship is an artifact of the ecological principle that a niche defines the ultimate distributional unit of species and no two species living in the same area can occupy the same niche. Each species of animal can utilize different portions of a common area. Thus, multispecies grazing allows for more efficient utilization of resources.
Factors Affecting Forage Selection
One of the main factors that dictate the type of forages an animal within the same class of digestive system (i.e., ruminant) consumes is body size. Large-bodied animals can meet their nutrient requirement with lower quality forage because they can consume larger total amounts of feed within the same time period than animals with smaller body sizes. Smaller sized animals require more time per unit of body weight to select higher quality feed items from the environment.
Dietary overlap and selection determines the effect of multispecies grazing on both pasture composition and carrying capacity. Theoretically, the proper mix and number of animals is a function of livestock dietary preferences, animal forage demand and botanical composition. Maximum benefit from multispecies grazing will occur when the proper substitution ratio of one livestock species for another occurs. Replacement ratios of five sheep per cow are commonly used and are based on relative differences in forage consumption. However, a suggested rule of thumb is that one ewe can be added per cow on moderately stocked rangelands without affecting cattle production. Limited studies have suggested that animal performance (weight gain) increased six and 30 percent for cattle and sheep, respectively, when grazed together than when each species grazed alone. Similarly, multispecies grazing was reported to increase animal production per unit area by 24 and nine percent compared to grazing cattle and sheep alone, respectively.
In a recent study conducted at the University of Wyoming with admittedly short sample time and limited numbers, a 52 percent increase in available grazing days were detected when sheep followed cattle compared with cattle following sheep grazing on irrigated meadows. Perhaps the selectivity of sheep while grazing allowed for re-growth of the plants that were initially grazed by cattle.
Multispecies grazing is probably not right for everyone; however, it should not have the negative connotation that is commonly associated with multispecies grazing. It is apparent that both sheep and cattle can co-exist, and likely have beneficial effects on plant utilization and range/pasture health due to differences in plant selection.