THE EFFECT OF LEVEL OF INCLUSION OF THE LEGUME DESMODIUM UNCINATUM AND THE USE OF MOLASSES OR GROUND MAIZE AS ADDITIVES ON THE CHEMICAL-COMPOSITION OF GRASS-LEGUME AND MAIZE-LEGUME SILAGES

The effect of the inclusion rate of legume and use of molasses or grou nd maize as additives on the chemical composition of grass-and maize-l egume silages was investigated in two experiments. In experiment 1 the effects of adding molasses or ground maize to star grass (Cynodon nle mfluensis) with or without legume (Desmodium uncinatum) at ensiling we re studied. Four additive treatments (no additive, molasses, 50 and 10 0 g ground maize/kg fresh weight) were combined with four levels of le gume (no legume, 150, 300 and 450 g/kg fresh weight) in a factorial ar rangement of treatments. Sealed plastic bags containing about 15 kg of compressed material were used and each treatment was replicated three times. In experiment 2 the effect of adding graded levels of legume ( D. uncinatum) to maize (Zea mays) at ensiling was studied in a complet ely randomised block design. Four levels of legume were used at ensili ng: no legume, 150, 300 and 450 g/kg fresh weight. The same procedure as that used in experiment 1 was applied, All the grass silages were w ell fermented. Addition of ground maize and molasses increased the dry matter content of grass silage (P < 0.001). Molasses addition resulte d in lower (P < 0.05) levels of volatile nitrogen and higher (P < 0.05 ) lactic acid content compared to the control and the ground maize tre atments. The inclusion of legume above 300 g/kg fresh weight raised th e pH, volatile nitrogen and total nitrogen content of grass silages (P < 0.001). The increase in pH and volatile nitrogen content was less w hen the silages were treated with additive, especially molasses. All t he maize silages were well fermented, with low pH and volatile nitroge n levels. Crude protein level was increased from 60 to 90 g/kg dry mat ter in the silage with no legume and at the highest level of legume (4 50 g/kg) respectively. The pH increased from 3.7 in silages with no le gume to 4.2 when legume was added at the rate of 450 g/kg. The inclusi on of D. uncinatum improved the quality of both grass and maize silage s. However, the inclusion of legume above 300 g/kg fresh weight of gra ss silage would require the use of additives. (C) 1997 Elsevier Scienc e B.V.