
Dwarf and Tall Elephantgrass Genotypes under Irrigation as Forage Sources for Ruminants: Herbage Accumulation and Nutritive Value
2021; Multidisciplinary Digital Publishing Institute; Volume: 11; Issue: 8 Linguagem: Inglês
10.3390/ani11082392
ISSN2076-2615
AutoresRayanne Thalita de Almeida Souza, Mércia Virgínia Ferreira dos Santos, Márcio Vieira da Cunha, Geane Dias Gonçalves, Valdson José da Silva, Alexandre Carneiro Leão de Mello, James P. Muir, Robson Elpídio Pereira Ribeiro, José Carlos Batista Dubeux,
Tópico(s)Pasture and Agricultural Systems
ResumoThis two-year study evaluated the effect of Pennisetum purpureum genotypes under rainfed or irrigated conditions, during the dry and rainy seasons, on herbage, leaf, and stem dry matter (DM) accumulation rates, nutritive value, and carbohydrate and protein fractionation. Treatments were tall (Iri 381 and Elefante B) or dwarf (Mott and Taiwan A-146 2.37) genotypes under rainfed or irrigated conditions. Taiwan A-146 2.37 (146 kg DM ha per day) showed similar herbage accumulation rate (HAR) to tall genotypes during the rainy season (124 and 150 kg DM/ha per day, respectively). Dwarf genotypes showed differences in leaf accumulation rate (LAR) (66 and 49 kg DM/ha per day). Mott leaf had less neutral detergent fiber (NDF) (589 g/kg DM) than Taiwan A-146 2.37 (598 g/kg DM), and tall genotypes had generally greater NDF (668 g/kg DM) than the dwarf genotypes. Irrigation increased fiber deposition in the leaf. Stems of all genotypes had lower in vitro digestible dry matter (IVDDM) (378 g/kg DM) under rainfed conditions in the rainy season. Leaf from irrigated plots had 23% more carbohydrate C fraction (160 g/kg CHO) than those from rainfed plots (122 g/kg CHO). Dwarf genotypes had generally greater nutritive value than tall genotypes. These genotypes show promise under irrigation to fill forage gaps during dry periods.
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