FERMENTATION CHARACTERISTICS AND CHEMICAL COMPOSITION OF TANZANIA GRASS SILAGE CONTAINING ADDITIVES

The objective of this study was to evaluate the fermentation characteristics and chemical composition of Tanzania grass silage containing additives. The following treatments were applied: silage without additive (SWA); silage treated with 2.17% limestones (SLS); silage treated with 2.17% urea (SUR), and silage treated with a combination of additives: 7.5% corn meal, 5.3% molasses powder, 1.1% urea and 1.1% limestone (SA1), and 10% corn meal, 2.93% molasses powder, 1.1% urea and 0.97% limestone (SA2). All silages containing additives exhibited a higher mean pH than SWA, but this did not negatively affect their fermentation quality. The titratable acidity of SWA (7.84) was higher than that of SUR (3.28), SLS (4.80), SA1 (3.30) and SA2 (3.80). The mean ammoniacal nitrogen was 10% lower in relation to total nitrogen in all silages, except for SUR, indicating a good fermentation profile. Effluent loss was lower for silages containing additives (P<0.005), with losses of 22.5, 12.1, 12.3 and 7.85 kg/t for SLS, SUR, SA1 and SA2, respectively, compared to SWA (46.1 kg/t). Dry matter content, total digestible nutrients and non-fibrous carbohydrates increased with inclusion of the additives, while neutral detergent fiber and hemicellulose content decreased. Dry matter digestibility was higher in SA1 and SA2 (45.8% and 44.4%, respectively) compared to the other silages, while SA2 did not differ from SWA (43.4%). The combination of chemical and organic additives had a positive synergistic effect to reduce effluent losses, neutral detergent fiber and acid detergent fiber and to increase dry matter digestibility, thus increasing nutrient availability. These silages therefore represent a good-quality final product.