Canopy characterization and nutritive value of stockpiled 'Floralta' limpograss (Hemarthria altissima)

Authors: SOUSA DE ABREU, DACILELE - University Of Florida; DUBEUX, JOSE - University Of Florida; SANTOS, ERICK - University Of Florida; QUEIROZ, LUANA - University Of Florida; Jaramillo, David; GARCIA, CARLOS - University Of Florida; LONGHINI, VANESSA - University Of Florida; SOUZA, RAYANNE - University Of Florida; HOMEM, BRUNO - Embrapa; RUIZ-MORENO, MARTIN - University Of Florida

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2022
Publication Date: 8/23/2022
Citation: Sousa De Abreu, D., Dubeux, J., Santos, E., Queiroz, L., Jaramillo, D.M., Garcia, C., Longhini, V., Souza, R., Homem, B., Ruiz-Moreno, M. 2022. Canopy characterization and nutritive value of stockpiled 'Floralta' limpograss (Hemarthria altissima). Agronomy Journal. 114(4):2407-2414. https://doi.org/10.1002/agj2.21081.
DOI: https://doi.org/10.1002/agj2.21081

Interpretive Summary: Limpograss [Hemarthria altissima (Poir.) Stapf and C. E. Hubb.] has been gaining ground in beef cattle production as a stockpiling option. This study evaluated canopy characteristics of stockpiled pastures of limpograss cv. ‘Floralta’ over two cool seasons. Treatments included canopy layers (upper third, middle, lower third) and plant fractions (leaf and stem) arranged in a randomized split block design. Response variables included forage mass, canopy height and density, proportion of leaf and stem, and leaf and stem nutritive value within each layer. Forage mass fluctuated throughout the season, decreasing with time. The lower canopy layer had the greatest proportion of stem whereas the upper layer had greatest proportion of leaves. The Leaf portion was more digestible than stem portion of the canopy. Leaf:stem ratio was greater in the upper layer, but similar between the middle and lower layers. Stockpiled limpograss maintained leaf and stem digestibility and can be used as an alternative to reduce feeding costs in North Florida during the cool season.

Technical Abstract: Limpograss [Hemarthria altissima (Poir.) Stapf and C. E. Hubb.] has been gaining ground in beef cattle production as a stockpiling option. This study evaluated canopy characteristics of stockpiled pastures of limpograss cv. ‘Floralta’ over two cool seasons. Treatments included canopy layers (upper third, middle, lower third) and plant fractions (leaf and stem) arranged in a randomized split block design. There were 12 pastures (blocks) measuring 1.2 ha each. Response variables included forage mass, canopy height and density, proportion of leaf and stem, and leaf and stem nutritive value within each layer. Forage mass fluctuated throughout the season, varying from 4410 kg DM ha-1 in December to 7220 kg DM ha-1 in October. Canopy bulk density was greater in February compared to November and December (290 vs. 145 kg ha cm-1), and similar to October and January (200 kg ha cm-1, on average). The lower canopy layer had the greatest proportion of stem whereas the upper layer had greatest proportion of leaves. Leaf had greater IVDOM (700 g kg-1) compared to stem (600 g kg-1). Leaf:stem ratio was greater in the upper layer (1.12), but similar between the middle and lower layers (0.4, on average). Leaf CP was greater than stem CP 70 vs. 20 g kg-1), with no differences between stem CP across evaluation dates. Stockpiled limpograss maintained leaf and stem digestibility and can be used as an alternative to reduce feeding costs in North Florida during the cool season .