Interspecies variation of forage nutritive value and nonstructural carbohydrates in perennial cool-season grasses
Knowledge of grass genotypes nonstructural carbohydrate (NSC) variation is one component to be considered when developing a successful forage and livestock management program. The objective of this study was to determine variations in concentrations of NSC, crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) among perennial cool-season grasses grown in the southern Great Plains at the preheading stage. Grasses evaluated included four tall fescue (Festuca arundinacea L.), two Festulolium (Lolium. multiflorum Lam. x Festuca arundinaceae), one tall wheatgrass [Thinopyrum ponticum (Podp.) Z.-W. Liu & R.-C. Wang], two intermediate wheatgrasses [T. intermedium (Host) Barkworth & D.R. Dewey], and four smooth bromegrasses (Bromus inermis Leyss). Grass species influenced forage concentrations of NSC, CP, NDF, and ADF. Averaged across years, concentrations of forage total NSC, CP, NDF, and ADF ranged from 70 to 112, 81 to 138, 548 to 614, and 288 to 321 g kg–1 dry weight (DW), respectively, among the 13 entries. Differences in the relative contribution of each NSC component to total NSC were small among the five species. Averaged across the entries, glucose, fructose, sucrose, fructans, and starch accounted for 14, 10, 15, 38, and 23% of total NSC, respectively. Producers seeking to improve the provision of energy to livestock would be served best by using smooth bromegrass with superior NSC concentration rather than by a tall fescue entry with low NSC concentration.