Bh. Dzowela et al., EFFECT OF DRYING METHOD ON CHEMICAL-COMPOSITION AND IN-VITRO DIGESTIBILITY OF MULTIPURPOSE TREE AND SHRUB FODDERS, Tropical grasslands, 29(4), 1995, pp. 263-269
Methods of drying fodder (sun-air- vs oven-drying) from 8 multi-purpos
e trees and shrubs were compared with freeze-drying in one experiment.
Twelve-month-old coppice foliage (leaf and petioles) was separated fr
om browseable stem components. The samples were either sun-air-dried f
or 3 days at 25 degrees C maximum day temperature or oven-dried at 65
degrees C for 48 hours. These dried samples were compared with freshly
cut samples that were freeze-dried in liquid nitrogen. In a second ex
periment, both leaf and browseable stem components of the fodder were
either sun-air- or oven-dried as in Experiment 1 above. Dry matter, ac
id and neutral detergent fibre (ADF; NDF), lignin, soluble polyphenoli
cs, NDF insoluble condensed tannins, total N and NDF-N concentrations
were determined. The in vitro digestibilities of both organic and dry
matter (IVOMD, IVDMD) were also determined. Major differences were rec
orded in fibre and nutrient concentrations between multi-purpose tree
species, fodder components and drying methods. Flemingia macrophylla a
nd Acacia angustissima had the lowest overall IVDMD, probably on accou
nt of their high ADF, NDF and lignin concentrations. Oven-drying resul
ted in an overall increase in ADE NDF and lignin concentrations compar
ed with sun-drying and freeze-drying. However, oven-drying resulted in
an overall reduction in soluble polyphenolics, total N, NDF-N and IVO
MD. The implications of the effects of drying method on in vitro diges
tibility values are discussed in the context of preservation of the fo
dders for dry season use.