Propanol in maize silage at Danish dairy farms

Abstract The objective of the present study was to investigate the prevalence maize silage containing propanol, the seasonal variation in propanol content of maize silage, and correlations between propanol and other fermentation products in maize silage collected from 20 randomly selected Danish dairy farms. Propanol concentrations in samples ranged from not detectable to 9.1 g/kg DM. Propanol concentrations were positively correlated with concentrations of propyl acetate, acetic acid, 2-butanol, propanal, ammonia, and propionate, and negatively correlated with the concentration of l-lactate. At 4 out of 20 farms, the maize silage had ≥5 g propanol/kg DM. The present study indicates that dairy cows in Denmark are commonly exposed to propanol and that approximately 20% of the dairy cows will have an intake in the range of 75–100 g propanol/d under common feeding conditions.