Effects of animal manures and cutting height on the chemical composition of two Panicum maximum varieties (Local and Ntchisi) harvested at different stages of growth

An experiment was conducted to determine the effects of animal manures and cutting height on the chemical composition of two Panicum maximum varieties harvested at different stages of growth. The experiment was laid out as a split-split-split plot design with four manure types (cattle, swine, poultry, and control) assigned to the main plot, three stages of growth (8, 10, and 12 weeks) assigned to the sub-plots, three cutting heights (10, 15, and 20 cm above ground) allotted to the sub-sub-plot, and P. maximum varieties (Local and Ntchisi) allotted to the sub-sub-sub-plot with three replicates. Results showed that swine and cattle manure fertilized grasses recorded (P<0.05) higher crude protein (CP) content than the unfertilized and poultry manure fertilized grasses. The grasses defoliated at 8 weeks recorded higher CP (10.37%), ether extract (8.77%) and ash (9.60%) compared to those harvested at 10 and 12 weeks respectively. Ntchisi variety recorded higher ether extract (8.94%) and ash (9.58%) contents than the local variety. However, the neutral detergent fibre (NDF) and acid detergent fibre (ADF) of the grasses increased with advancement in the growth stage. Grasses cut at 15 cm had higher Ca (4.66 g kg-¹) while those cut at 20 cm recorded higher P (4.01 g kg-¹) concentration. The quality of the grasses was influenced by the interactions (manure × harvest time; manure × variety × cutting height; manure × cutting height × harvest time). Therefore, to harness the best nutritive P. maximum for the feeding of ruminants in Nigeria and other parts of the tropics, manure (cattle, swine, and poultry), harvest time, variety and cutting height, and their interactions are important factors to be considered.