Assessment of the Potential Value of Twelve Browse Legume Trees Using In Vitro Gas Production and Coefficient of Preference Technique

Abstract

Twelve tropical multipurpose browse plants were evaluated for their chemical composition, metabolizable energy (ME), organic matter digestibility (OMD), in vitro gas production characteristics and preference by the West Africa Dwarf (WAD) goats using cafeteria method. The crude protein content of the legumes ranged from 9.79 to 29.53 g/100 g DM and varied significantly (P< 0.05). Ether extract varied widely ranging from 6.0-13.1 g/100 g DM. The total gas produced at the end of 24 hrs of fermentation varied between 13.67 to 20.83 ml per 200 mg per DM. In-vitro characteristic parameters also varied significantly amongst the legumes. Initial gas (a) produced ranged from 0.00 to 4.67 ml, insoluble but degradable fraction (b) varied from 14.66 to 23.00 ml while a+b which is the potential degradability varied from 13.67 to 24.00 ml. Methane production ranged between 8.33 and 13.83 ml. Also, metabolizable energy (ME), organic matter digestibility (OMD) and short chain fatty acid of the forages varied from 4.81 to 6.58, 37.20 to 52.09 and 0.27 to 0.57 respectively. Neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) varied significantly (P< 0.05), ranging from 41.82 to 65.55 g/100 g DM, 26.72 to 49.38 g/100 g DM, and 6.05 to 13.72 g/100 g DM respectively. The ash content of the plant species also varied significantly (P< 0.05), ranging from 5.14 in Albizia odoratissima to 8.93 g/100 g DM in Cassia fistulosa. A wide range of preference was observed, as Leucaena leucocephala was most preferred. The results showed that these browse species are potential sources of nutrients for ruminants as dry season basal forage.