Herbage Accumulation and Nutritive Value of Limpograss Breeding Lines Under Stockpiling Management

Abstract

Supplements or conserved forage are often used to overcome forage quantity deficits for beef cattle, but stockpiled forage can be more economical. Limpograss [Hemarthria altissima (Poir.) Stapf & C.E. Hubb.] is the best available species for stockpiling in Florida because it is productive in autumn and maintains greater digestibility than other grasses at advanced stages of maturity. New limpograss hybrid breeding lines have been developed, but they have not been tested under stockpiling. Three limpograss breeding lines (1, 4F, and 10) and the most-used cultivar, Floralta, received 50 or 100 kg N ha(-1) at initiation of stockpiling and herbage accumulated for 8, 12, or 16 wk. Entry 4F had greater herbage accumulation (7.3 Mg ha(-1)) than Entries 10, 1, and Floralta (6.1, 6.0, and 5.4 Mg ha(-1), respectively). Entry 4F also had greater in vitro digestible organic matter (IVDOM) concentration (530-594 g kg(-1)) than Entries 1 and Floralta, but 4F was not different from Entry 10 (519-531 g kg(-1)) after 12 and 16 wk of accumulation. As stockpiling period increased from 8 to 16 wk, herbage accumulation increased from 5.3 to 7.4 Mg ha(-1), dead material proportion increased from 1 to 10%, and herbage crude protein (CP) decreased from 44 to 32 g kg(-1). Limpograss hybrids 4F and 10 are superior to Floralta for stockpiling, stockpiling period should not be longer than 12 wk, and protein supplement will be required to achieve satisfactory animal performance on stockpiled limpograss.