Chemical composition, rumen degradation, and gas production characteristics of some multipurpose fodder trees and shrubs during wet and dry seasons in the humid tropics

Seasonal variations in chemical composition, dry matter (DM) and nitrogen (N) degradation and gas production characteristics of 18 multipurpose trees and shrubs (MPTs) from the humid lowlands of West Africa were evaluated. The MPTs have potential for the development of integrated crop and livestock agroforestry technologies in the region. The experiment was conducted in Ibadan, southestern Nigeria during the main-wet (April-August) and dry (December-March) seasons. The MPTs were ranked by their degradation and gas production characteristics, and these were found to be related to chemical composition. There were wide variations among MPTs in crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and proanthocyaidin contents, DM and N degradation, and gas production characteristics. Dry matter degradation during the dry season ranged from 4126 to 868 g kg-1 and for N508 to 950 g kg-1. Crude protein, and rates of DM and N degradation were significantly correlated (r=0.48, P=0.037 for DM and r=0.56, P=0.032 for N). The rates and extents of DM and N degradation were significantly correlated with NDF and ADF during the wet season (r=-0.47 to-0.63). The volume of gas produced (r=-0.48 to -0.67) and initial gas production (r=-0.64 to -0.73) were highly correlated with the NDF and ADF in both seasons. The rate of DM degradation was significantly correlated with gas production variables in the minor-wet season. Ranking of the MPTs based on extent of DM and N degradation, and volume of gas produced for the main-wet and dry seasons were highly correlated. Based on degradation and gas production characteristics in the main-wet and the dry seasons, F. exasperata, S. nodosa, S. siamea, S. spectabilis, G. sepium, L. leucocephala and L. diversifolia were superior in quality to M. thonningii, A. angustissima and pterocarpum

Feed value of multipurpose fodder trees and shrubs in West Africa: Edible forage production and nutritive value of Millettia thonningii and Albizia lebbeck

Harvests were made at the end of the main (April-August) and minor (September-November) wet, and dry (December-March) seasons for two years. Dry season edible forage samples were analyzed for concentrations of crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (NDF), acid detergent lignin (ADL), cellulose (CL), soluble phenolics (SOPH) and proanthocyanidins (PAs). In sacco dry matter (DM) and nitrogen (N) degradation and in vitro gas production (GP) chaaracteristics were also determined on dry season edible forage samples.Edible forage production of M. thonningii was significantly lower than A. lebbeck during the wet seasons. Millettia thonningii had relatively lower CP and PAs, but higher NDF, ADF, ADL, CL and SOPH than A. lebbeck. In sacco DM and N degradation and in vitro GP parameters of M. thonningii were significantly lower than A. lebbeck. Parameters of in sacco DM degradation and in vitro GP were highly correlated. Milletia thonningii appeared to be of lower feed value than A. lebbeck based on edible forage production, chemical composition, in sacco DM and N degradation and in virto GP characteristics

Seasonal dynamics in dry matter degradation of browse in cattle, sheep and goats

Rumen degradation characteristics of DM in edible forage of 25 multipurpose tree and shrub fodders (MPTS) harvested at the end of the main-wet (April-August 1992), minor-wet (September-November 1992) and dry (December 1992-March 1993) seasons were determined in rumen-fistulated Bunaji cattle (BC), West African Dwarf (WAD) sheep (WS) and WAD goats (WG) in Ibadan, southwestern Nigeria. Air dry samples of edible forage were incubated for 3, 6, 12, 36, 48, 72 and 96 h in three each of BC, WS and WG castrates fed a basal diet of Panicum maximum supplemented with Gliricidia sepium leaves. Dry matter degradation constants were estimated from non-linear regression. Concentrations of crude protein, neutral detergent fibre and insoluble proanthocyanidins varied widely among seasons. Classification of the MPTS based on a (soluble fraction), b (rumen degradable fraction), c(rate of degradation)) and PD (potential degradation) varied among BC, WS and WG within season. Using PD as an index of forage quality, the MPTS were classified into high, medium and low groups. The b and PD in BC during the dry season were significantly higher than in WS and WG. The results suggested the existence of intraspecies and interspecies variation in rumen degradation characteristics of DM of the MPTs in BC, WS and WG. The PD in BC was highly correlated to WS and WG in the wet seasons.Thus, rumen degradation could be useful in the initial screening of MPTS for further nutritional studies