Effect of Amylolytic and Cellulolytic Enzymes on Whole Plant Corn Silage: Characteristics of Silage and Animal Digestion

Abstract

Enzyme additives have been added to forage at ensiling to improve nutritive value. The aim of this study was to evaluate effects of adding exogenous enzymes to silage on fermentative losses and profile, aerobic stability, chemical composition, in vitro degradation, microbial quality, and nutrients intake and digestibility. Treatments were control (CON); addition of exo-1,4-α-glycosidase glucoamylase (GLU; Kerazyme 3035, Kera Nutrição Animal, Bento Gonçalves, Brazil); addition of β-glucan 4-glucanhydrolase (CEL); and GLU + CEL. Data from the silo experiment were analyzed using PROC MIXED of SAS, with fixed effects of glucoamylase and cellulase, and interaction effect between them. In vivo experiment analyses also included fixed effect of Latin Square and period, and random effect of animal within Latin Square. CEL increased (P ≤ 0.038) gas losses and effluents production, CEL and GLU decreased (P = 0.039) DM recovery compared to control but not differ from GLU+CEL. CEL silage had higher (P ≤ 0.021) starch and crude protein and in vitro digestibility of DM and NDF (P ≤ 0.032), while GLU had higher (P = 0.001) ADF. CEL showed lower (P = 0.012) ethanol content and higher (P = 0.02) anaerobic bacteria counts, while GLU showed higher (P = 0.012) lactate concentration and lower (P ≤ 0.002) counts of bacteria and fungi. Lambs fed with CEL presented higher (P ≤ 0.012) digestibility coefficients for DM, OM, CP and NDF. Decrease on DM recovery indicates no improvements on the nutritive value of silage. On the other hand, cellulolytic enzyme positively affected animal digestion.