Solubility characteristics of forage components and their digestibility

The principal objective of this study was to isolate forage chemical components of uniform nutritive characteristics and, if attainable, describe and quantify variations in digestibility of non-uniform components in terms of their chemical composition. Chemical determinations in most forages included: dry matter (DM); ash (OM); crude protein (CP); neutral detergent extract, gravimetric (NDEg) and colorimetric (NDEc); neutral detergent fiber (NDFg); acid detergent fiber (ADF); crude fiber (CF); easily hydrolyzable hemicellulose, gravimetric (DHHc); cellulose, gravimetric (Cg) and colorimetric (Cc); acid insoluble lignin (AIL); acid insoluble ash (AI Ash); permanganate lignin (P.L.) and silica (SiO). Additional chemical analyses included solubilization of the sample's NDF in cupriethylene diamine (CED) and fractionation of its insoluble residue according to ease of hydrolysis. This fractionation yielded CED soluble (NDFs, EHHs, DHHs, Cs, Ls) and CED insoluble (NDFi, EHHi, DHHi, Ci, Li) components of both forage and feces, and their respective digestibilities. In vitro dry matter digestibility (IVDDM) was also determined for most forages. ..