Formaldehyde as a silage additive. I. The chemical composition and nutritive value of frozen lucerne, lucerne silage, and formaldehyde-treated lucerne silage

Abstract

Formaldehyde-treated silages, frozen lucerne, and untreated silage were prepared from a lucerne stand and offered to Merino wethers. Formalin was applied at rates of 16.6, 24.9, and 33.1 g formaldehyde per 100 g crude protein. Formaldehyde-treated silages had significantly lower concentrations of ammonia nitrogen and total and individual organic acids than did untreated silage, and hence the ensiling fermentation was inhibited by formaldehyde. Formaldehyde treatment of lucerne partly protected plant proteins against microbial degradation during in vitro rumen liquor digestion and so reduced ammonia nitrogen concentrations in the supernatant. Ad libitum dry matter intakes and in vivo dry matter and nitrogen digestibilities were significantly lower for the treated silages than for frozen lucerne or untreated silage. The treatment of lucerne with formaldehyde at concentrations of 16.6 g formaldehyde per 100 g crude protein and above was not a suitable method of controlling the ensiling fermentation to increase the voluntary consumption of lucerne silage by sheep.