CHEMICAL COMPOSITION, FERMENTATION CHARACTERISTICS AND ANTI-NUTRITIONAL CONTENT OF ENSILED MAIZE COB - SWEET POTATO VINE MIXTURE

Abstract

The study was conducted to assess the effect of dry matter levels on silage characteristics of maize cob and sweet potatoes vine mixtures. Maize cob (MC) and sweet potato vine (SPV) were chopped and mixed to provide dry matter levels of 70 %, 65 %, 60 % and 55 %, thus each level was considered as treatment T₁, T₂, T₃ and T₄, respectively. The materials were ensiled for 45 days in Ziploc polyethene bags, which were placed inside black plastic containers. Each container carried one treatment with five replicates. There was a significant (p <0.05) difference in dry matter (902.40±0.40 – 975.55±2.74 g/kg), crude protein (39.70±5.25 – 69.40±1.44 g/kg), neutral detergent fibre (525.55±1.07 – 661.70±30.48 g/kg), and hemicellulose (163.45±2.34 – 302.30±4.04 g/kg) across the treatments. A linear decrease (p <0.05) was observed in crude protein (CP) content, but dry matter (DM) and neutral detergent fibre (NDF) increased (p<0.05) across the treatments. Similarly, total volatile fatty acids (8.00±0.58 – 10.67±1.33 µmol/L) showed a numerical decrease at lower DM levels. However, pH (4.22±0.13 – 4.73±0.06) increased (p<0.05) linearly across the treatments. No significant difference (p>0.05) was observed in alkaloid and tannin contents across all the treatments. Invariably, flavonoid content increased (p<0.05) inversely with dry matter levels. Presentation of treatment diets (silage) to sheep and goats received different responses. Goats preferred T₁ while sheep showed a total preference to T₄ after spending little time on T₂ and T₃ silages.  It was concluded that low dry matter levels encourage the formation of high-quality silage. It was further deduced that microbial activities increased with a decrease in dry matter levels. Hence, for good-quality silage using maize cob and sweet potato vine, 55 % DM level is recommended.