Chemical composition and in vitro evaluation of the nutrient content of Panicum maximum-Moringa oleifera diets
The ruminants in the tropics are slow growing, arising from low quality feed. The use of indigenous legume trees and Guinea grass is a good strategy for an improved livestock performance. The study determined the chemical composition, anti-nutritional factors and in vitro gas production characteristics of Panicum maximum-Moringa oleifera mixed diets. Five diets were formulated such that Panicum maximum was substituted with Moringa oleifera at ratio 0, 25, 50, 75 and 100% in diets A, B, C, D and E respectively and they were incubated for 48 hr using in vitro gas production technique. The proximate composition, fibre franction, anti-nutrient, mineral contents and in vitro characteristics of the P.maximun- M.oleifera mixed diets were determined and all data collected were subjected to one way analysis of variance and where there were significant (P<0.05) differences, means were compared using Duncan multiple range F-test. The results revealed that the observed values were significantly (p<0.05) influenced by the inclusion of Moringa oleifera in the diets with the exception of dry matter and gross energy. Dry matter values (87.00-89.72g/100g) decreased with the increased inclusion of Moringa oleifera in the diets, while protein content (9.26-26.68g/100g) increased with the increased inclusion of Moringa oleifera in the diets. It implied that the diets could be good sources of protein and energy that would meet the requirement of small ruminants for growth and production. Neutral detergent fibre and Acid detergent lignin values decreased with the increased inclusion of Moringa oleifera in the diets. However, the values of acid detergent fibre, hemicelluloses and cellulose ranged from 20.13 to 43.44g/100g, 6.88 to 14.45g/100g and 14.65 – 31.48g/100g respectively. Antinutrient values were significantly (p<0.05) influenced by the treatment. Tannin concentrations in these diets were below the 6.00g/100g toxic level for small ruminants. The concentrations (g/100g) of Ca (0.12 – 2.74), P (0.05 – 0.12), K (0.17 – 2.78), Na (0.07 – 0.27), Fe (0.07 – 0.17) and Zn (0.04 – 0.16 ) varied significantly (p<0.05), the observed values were higher in diet E that contained 100% Moringa oleifera leaves than other diets. The high contents of these minerals in Moringa oleifera indicated that the requirements of sheep and goats for these minerals could be met if the plant is fed with grass ad libitum. There were significant (p<0.05) differences among the treatment means of metabolizable energy (ME 3.44 – 5,58 MJ/kg DM), organic matter digestibility (OMD 30.96 – 43.65 g/100g), short chain fatty acids (SCFA 0.05 – 0.26 μmol) and methane (2.00 – 6.00 ml). Total gas and methane production increased with incubation period and the highest values of OMD was observed in the 48th hour of incubation. It can be concluded that with the enhanced values of crude protein, gross energy, metabolizable energy, short chain fatty acids and low methane production, the Panicum maximum-Moringa oleifera diets have potential that would meet the nutrient requirements of small ruminants in the tropical regions particularly during the dry season.
Keywords: Gas production, in vitro, nutrients, Moringa oleifera, Panicum maximum