Effect of slashing, grazing, burning and maturity on quality of natural grassland herbage in the Accra Plains
1980
Fianu, F.K., Department of Animal Science, University of Ghana, Legon, Ghana | Wench, J.E., Department of Crop Science, University of Guelph, Ontario, Canada
Effects of slashing, grazing and burning pretreatment and maturity dates on leafiness, in vitro dry matter digestibility (IVD) and nitrogen (N) content of leaves and stems of Sporobolus pyramidalis Beanv., Heteropogon contortus (L.) Beanv., Panicum maximum Jacq. and Andropogon gayanus Kunth. var. bisquamulatus (Hochst) Hack., were studied at the University of Ghana, Legon during the 1974/ 75 rainy seasons. Pretreatment did not affect leafiness or N content. A. gayanus remained vegetative for longer periods and maintained higher leatiness. P. maximum was highest in IYO at all stages of growth. A. gayanus had almost the same IVD as the short grasses at the early stages of growth. After 10 weeks, S. pyramidalis and H. contortus declined more rapidly in IVD; falling below A. gayanus by the 17th week. Leaf IVD was higher than stem IVD in P. maximum, S. pyramidalis and H. contortus but the stem IVD of A. gayanus was higher than its leaves. Species difference were not consistent in N content although N content of A. gayanus was lower than the others from the 4th week to the 6th week. Leaf N was higher than stem N in all species. Quality declined with advancing maturity but the regressions did not appear to be reliable quality predictors because they were inconsistent from one year to the next and from species to species. Grazed before 8 weeks maturity, P. maximum would probably meet the nutrient requirements of fast growing ruminants. The floristic change in grazing lands dominated by P. maximum and A. gayanus to communities dominated by H. contortus and S. pyramidalis is nutritively a retrogressive change. Such deteriorated pasturage would not support highly productive livestock.
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