Seasonal-accumulated growth and forage quality of range grasses for fall and winter grazing

Abstract

The production and subsequent feeding of forage during winter is a major expense for livestock producers. Fourteen perennial range forage grasses including crested wheatgrass (WG) [Agropyron cristatum and A. desertorum] , intermediate WG [Thinopyrum intermedium], tall WG [T. ponticum], quackgrass [Elytrigia repens] × bluebunch WG [Pseudoroegneria spicata] RS hybrids, Altai [Leymus angustus] wildrye (WR), basin [L. cinereus] WR, smooth bromegrass [Bromus inermis], and orchardgrass [Dactylis glomerata] were evaluated from 1992 to 1994 for total dry matter (DM) production (November harvest only), crude protein (CP), neutral (NDF), and acid (ADF) detergent fiber from November through March in northern Utah. Mean species DM production rankings (P < 0.01) combined across years were: RS hybrids > smooth bromegrass > basin WR > Altai WR > intermediate WG > orchardgrass > tall WG > crested WG. Mean species CP rankings (P < 0.01) combined across years and harvests were tall WG > intermediate WG > orchardgrass > RS hybrids > crested WG > Altai WR > basin WR > smooth bromegrass. Levels of CP remained constant from November through March for all species and entries. Trends in NDF and ADF remained constant from November through January, but NDF increased slightly in March. Crude protein of the dormant grasses was below the level necessary to maintain ruminal function so protein supplementation would be necessary. Key words: Range grasses, winter forage quality, yield, extending the grazing season