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.