FODDER YIELD AND QUALITY OF FOUR ELEPHANT GRASS VARIETIES PLANTED IN THE DRY SAVANNA REGION OF GHANA

Abstract

Two separate experiments were conducted to investigate the fodder yield and nutritive value of four varieties (16783, 16798, 16840 and local) of Pennisetum purpureum (Napier) grass in the savanna region of Ghana. A randomized complete block de sign was used for evaluating the yield performance of the four varieties over a 90-day period in Experiment 1. After 90-days, the fodder as harvested to a stubble height of 15 em and were used in experiment 2. The harvested fodder was separated into leaves, stem and whole and analyzed for nutrient composition and in vitro organic matter digestibility in a 4 x 3 factorial experiment in completely randomized design. The factors were the four varieties and three botanical fractions. There was no signific ant effect (P<0.05) of variety on biomass yield, tiller number, plant height and leaf: stem ratio. The biomass yield (DM kg/ha) ranged from 1354 to 3339 for the 16798 and local varieties respectively. Plant height was positively correlated (P<O.OOI) with fodder yield. There was a significant effect of variety x fraction interaction on hemicellulose concentration. The highest (P<0.05) hemicellulose was obtained in the leaf fraction of the local variety. The stem fraction for all the varieties was consistently lower (P> 0.05) relative to crude protein concentration with the least recorded in the local variety. Whilst variety x fraction interaction did not affect (P>0.05) gas production and degradation parameters, the main effect of variety and fraction was significant for some of the parameters. Gas production at 12, 24 and 48 h was significantly higher relative to the stem fraction. There was no significant difference (P<0.05) among the fraction for in vitro organic matter digestibility (IVOMD) and metabolizable energy (ME). The study revealed a superior yield performance for the local variety. The local and 16798 varieties were higher in organic matter digestibility. The stem fraction was highly digested compared to the leaf and whole at 12, 24 and 48 h.