In situ forestomach and intestinal nutrient digestibilities of sweet corn residues

Abstract

Sweet corn residue is a byproduct of the sweet corn processing industry accounting for 60–70% of the harvest. A study was conducted to determine chemical composition, ensiling characteristics, and nutrient digestibilities of both, as collected as ensiled sweet corn residues. Forestomach, intestinal and whole tract digestibilities of dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF) of both as collected and ensiled sweet corn residues were determined relative to a reference corn silage using two lactating cows fitted with ruminal and duodenal cannulae in a randomized complete block design. On DM basis, as collected and ensiled sweet corn residues contained similar NDF (average 577 g/kg), acid detergent fibre (ADF) (average 292 g/kg) and CP (average 89 g/kg) content. Ensiling reduced ( P<0.05) starch content and increased ( P<0.05) soluble CP and non-protein N levels of sweet corn residue. Effective ruminal degradabilities of DM and of NDF as collected and ensiled corn residues were similar, and lower ( P<0.05) than those of the corn silage. Ensiling increased ( P<0.05) effective ruminal CP degradability of sweet corn residue. Intestinal nutrient digestibilities were low for both sweet corn byproducts. Whole tract digestibility of CP and NDF were similar for all treatments. However, corn silage had a 12% higher ( P<0.05) whole tract digestibility of DM than the as collected and ensiled sweet corn residues. Ensiling had little effect on nutrient digestibilities of sweet corn residues and both sweet corn residues had reduced whole tract DM digestibility when compared to a reference corn silage.