Development of a Novel Enzymatic Pretreatment for Improving the Digestibility of Protein in Feather Meal

Abstract

This study describes the process of developing an enzymatic pretreatment to improvethe nutritional value of feather meal (FeM). In a first experiment, a full factorial design was used toexamine the effects of various incubation conditions on the solubilization of nitrogen in FeM. Weincubated FeM for 3 h with various levels of a commercial alkaline serine protease (Savinase®16L), sodium sulphite (Na2SO3), and digestion buffer. A Savinase® 16L level of 3% (%FeM v/w),Na2SO3 level of 3% (%FeM w/w), and digestion buffer level of 500% (%FeM w/w) were identifiedas the optimal conditions. Under these optimal conditions, 45% of the nitrogen in FeM wassolubilized. In a second experiment, we evaluated the effect of more economically sustainableincubation conditions on the in vitro digestibility of protein (pepsin-HCl digestibility andmultistep protein evaluation) in FeM. Two FeMs were incubated with 0.5% Savinase® 16L (%FeMv/w), 2% Na2SO3 (%FeM w/w), and 200% buffer (%FeM w/w) for 24 h. The pretreatment improvedpepsin-HCl digestibility by 7%–16% and the total tract degradable protein content by 14%–50%.Accordingly, this novel pretreatment could be applied in the animal feed industry to improve thenutritional value of FeM.