Effect of Exogenous Fibrolytic Enzymes Supplementation or Functional Feed Additives on In Vitro Ruminal Fermentation of Chemically Pre-Treated Sunflower Heads

Abstract

This study aims to provide possible utilization of sunflower head byproduct (SFH) as a feedstuff by implementing chemical pretreatments (4% sodium hydroxide (SFHNaOH) or 4% urea (SFHurea) and supplementation with either exogenous fibrolytic enzymes (EFE) or functional feed additive (FFA). The experimental EFE was a complex (1:1, v/v) of two enzyme products with high activity of β-1,3-1,4-glucanase and endo-1,4-β-D-xylanase and applied at 0 (SFHout), 1, 2, 5, and 10 µL/ gdry matter, while FFA was a fermentation byproduct rich in cellulase and xylanase activities, applied at 0 (SFHout), 0.5, 1, 2, and 4 mg/g DM. SFHurea had the highest (p p out had the highest (p out supplemented with EFE seems to be the most promising substrate to enhance microbial fermentation in vitro.

Keywords

• sunflower head
• chemical composition
• digestibility
• in vitro
• chemical pretreatments
• exogeneous enzymes