A recent review of grazing system literature in the Journal of  Range  Management  (32:250) by A. Van Poolen  and J. Lacey  shows  that a stocking  rate reduction will generally contribute more to range improvement  than implementation of a specialized grazing  system. However, one type of spe­cialized grazing system that can lead to improvement in livestock  production and range vegetation under certain conditions was not considered.  Kenneth Valentine of New Mexico  State University  (JRM, 1967, 20:395) first described this  system, and  named it  "Seasonal Suitability" grazing. Similar  principles apply to the use of complementary tame pastures in conjunction with native range.