IN VITRO PROTEIN SOLUBILITY AND SOLUBILIZATION OF SELECTED FEEDSTUFFS FOR RUMINANT FEEDING

Résumé

Protein solubility in mineral buffer, and protein degradability with bacterial protease, of condensed distillers solubles, distillers dried grains, brewers dried grains, raw, roasted and extruded soybeans, corn silage, haycrop silage, hay, corn gluten feed, multiage solulac and lactosy-urea (Ewoplus) were in­vestigated for use in ruminant feeding. The proteins of distillers dried grains, brewers dried grains, roasted and extruded soybeans and corn gluten meal were highly Insoluble in mineral buffer with average solubilities of 4.50%, 10.47%, 8.07%, 13.12% and 5.40% respectively. Lactosyl­urea (Ewoplus) was 100% soluble. The protease of streptomyces griseus was used to determine protein degradability. The degradable proteins of distillers grains, brewers grains, raw and roasted soybeans, and corn gluten meal were resis­tant to protease action. Extruded soybeans, distillers solubles, forage feedstuffs and Ewoplus were readily degradable.