Biomass yield and nutritive quality of four varieties of Pennisetum purpureum as influenced by three cutting intervals in the humid zone of Nigeria

This experiment was conducted to determine the effect of cutting intervals on the dry matter (DM) yield, yield components and nutrient contents of four varieties of Pennisetum purpureum. Varieties experimented include: Local green, Local purple, S13 and S15. These were planted in a randomized complete block design with three replicates. All the four varieties of P. purpureum were cut at intervals of 4, 8 and 12 weeks after cutback (WAC) to represent first, second and third cutting intervals respectively. Results showed that the dry matter yield of the P. purpureum grasses significantly decreased from first to third cutting intervals. Variety S15 recorded a higher (P < 0.05) dry matter yield (13.26 t ha-1) at the first cutting interval. Variety S13 had higher leaf proportion (89) at first cutting interval and tiller density (137.00 tiller-1 m2) at third cutting interval (than the other varieties). Cutting intervals had significant effect (P < 0.05) on the crude protein (CP) content of the grasses which was higher at second cutting interval for S15. In contrast, the neutral detergent fibre (NDF) and acid detergent fibre (ADF) increased from first to third cutting intervals for all the varieties. The CP and fibre contents of the Pennisetum varieties at different cutting intervals were within the levels recommended for optimum animal performance.