Passage and degradation kinetics of solid particles from agricultural residues

Abstract

The use of waste generated in the agroindustry can result in increased production at a relatively low cost compared to traditional ingredients, especially for producers with easy access to this waste. This study proposes to estimate the kinetics of passage and degradation of corn, soybean, wheat residues and corn silage in the gastrointestinal tract of cattle. Four rumen-fistulated animals with an average weight of 450 ± 50 kg were assigned to four treatments (corn, soybean, wheat residues and corn silage) in a 4×4 Latin square experimental design. The fiber from the residues and corn silage used to estimate the passage kinetics was marked with potassium dichromate, whereas the in situ technique was employed to estimate the fiber degradation kinetics. A larger potentially degradable fraction and a smaller undegradable fraction were observed for corn residue and corn silage, whereas no differences were detected between the materials for passage kinetics. The residue from corn processing is similar to corn silage in terms of degradation kinetics and mean fiber retention time, while the other residues have worse degradation kinetics than corn, which is due mainly to the elevated undegradable fraction. All the analyzed residues, as well as corn silage, share the same characteristics of fiber passage kinetics.