Ensiling of forage rather than drying for hay become more common in many areas because of weather condition, field losses and other risks. Lucerne protein is subjected to extensive degradation during ensiling. Organic and inorganic acids as silage additives could decrease protein degradation of lucerne during ensiling. Cows fed on formic acid treated lucerne silage produced more daily milk and milk per ton of harvested forage. The objective of this study was to determine the effects of diet containing untreated (U) or treated (T) lucerne silage with formic and sulphuric acids on performance of early lactating dairy Holstein cows.