Chemical composition, lipid peroxidation and in vitro ruminal fermentation of crown vetch (Coronilla varia L.) herbage and silage

Abstract

Crown vetch (Coronilla varia L.) is a widely spread legume species that can be used as a forage crop for herbivores. The crown vetch herbage was ensiled with 0, 4, or 8% of crushed barley grain on a wet basis. The crude protein (CP) and neutral detergent fiber in organic matter (NDFom) contents of crown vetch herbage were higher than those of crown vetch silages (p < .05). The malondialdehyde (MDA) concentrations of herbage and silages with barley grain were lower than that of silage without barley grain (p < .05). The linoleic acid (C18:2) percentage of total fatty acids in forage decreased with the ensiling process (p < .05). The addition of crushed barley grain in the ensiling process of crown vetch herbage preserved the α-linolenic acid (C18:3) percentage of total fatty acids (p < .05). The crushed barley grain positively affected dry matter (DM) and ammonia-nitrogen levels, acidity value (pH and lactic, acetic and propionic acids) and in vitro ruminal fermentation values (cumulative gas production, metabolic energy [ME], net energy lactation [NEL] and organic matter digestion [OMd]) of crown vetch silage (p < .05). The concentration of volatile fatty acids (acetic, butyric, propionic, iso-valeric and iso-butyric acids) in the in vitro ruminal fermentation fluid was similar in herbage and silages of crown vetch (p > .05). Consequently, crushed barley grain (especially 4% rate) in the ensiling process of crown vetch increased hemicellulose, easily digestible carbohydrates, linoleic acid, α-linolenic acid in silage and in vitro ruminal digestion parameters, positively affected silage acidity and decreased lipid peroxidation.