A selected set of wild herbivores on Lewa Wildlife Conservancy (LWC) and Ol Pejeta Ranch were evaluated for their utility value by productivity indexing based on a computer bio-economic model, Prying Livestock Productivity (PRY). PRY derives productivity of species based on feed energy efficiency (FEE). The respective FEE indices (Kenya shillings, Ksh, per kilogram dry matter, Ksh kg)1 DM) for consumptive use only on LWC and Ol Pejet Ranch for zebra, buffalo, impala, giraffe and eland were 9.23 and 9.20; 4.70 and 4.74; 4.05 and 3.42; 7.34 and 7.24; 6.21 and 6.06. With non-consumptive use included in productivity assessments on LWC and Ol Pejeta Ranch, the respective indices for zebra, buffalo, impala, giraffe and eland were 15.52 and 9.98; 21.10 and 6.34; 9.85 and 4.69; 14.41 and 9.92; 12.72 and 16.05. The buffalo and eland were the most productive species on LWC and Ol Pejeta Ranch respectively, while the impala was the least productive on the two units. Most herbivores on LWC were more productive than the same species on Ol Pejeta Ranch when touristic value was included in the indexing. However, without tourism, species in the two units had similar index values, except for the impala. It was concluded that tourism provides the main economic justification for utilization and conservation of the herbivores.