Abstract: The invention relates to the use of at least one bacterial amylase in feed for ruminant animals of the subfamily Bovinae in particular for improving milk yield, apparent digestibility of the diet fed, feedstuff dry matter disappearance, weight gain, and/or Feed Conversion Ratio (FCR). Examples of bovine animals are dairy cows and beef cattle. The invention also relates to the use of such amylases in feed and feed additives such as premix, concentrates and total mixed ration (TMR). The amylase may be used in combination with cellulase for improving milk yield and/or back fat thickness. Preferred amylases are derived from Bacillus halmapalus, licheniformis, and stearothermophilus and are preferably homologous to Bacillus stearothermophilus amylase.