Nutritional value of elephant grass in response to different harvest times in Roraima state, Brazil

The nutritional value of forage grasses is associated with the optimal harvest time. Forage should be harvested at a developmental stage that balances high nutritional value with ample forage production. Accordingly, this study aimed to evaluate the nutritional value of elephant grass (Pennisetum purpureum) harvested at different times in a forest-savannah transition region in Roraima state, Brazil. This included chemical analyses and in situ degradability assessments. A randomized block design was employed, evaluating five harvest times (35, 45, 55, 65, and 75 days), each with four replications. Existing forage banks were utilized. Following collection on predetermined days, samples were pre-dried for subsequent chemical analysis of dry matter (DM), mineral material (MM), organic matter (OM), ether extract (EE), crude protein (CP), and neutral detergent fiber (NDF). In situ degradability of DM and NDF was also assessed. Significant differences were observed in DM, MM, OM, CP, and EE (p < 0.01), as well as in the degradabilities of DM and NDF. As the harvest time of elephant grass increased, levels of CP, MM, EE, and the degradability of DM and NDF decreased, while OM, DM, and NDF contents increased.