We assessed diet quality and livestock weight gains for shortgrass steppe pastures dominated by Loamy Plains or Sandy Plains ecological sites.

When growing season precipitation is “normal,” livestock gains are higher on Sandy Plains ecological sites, and diet quality is not limiting livestock production.

Conversely, when growing season precipitation declines by 20%, digestible organic matter, but not crude protein, influences livestock gains. These negative effects on livestock gains are more pronounced for the Loamy Plains ecological site.

Pastures with multiple ecological sites may provide range managers greater forage diversity for livestock and higher livestock gains during dry growing seasons.