The invention described in this application relates to a method of increasing the amount of weight gained by the mammal during a feeding period, to a method of increasing the amount of milk replacer consumed by the mammal during a feeding period, to a method of decreasing the amount of scour of the ruminant during a feeding period, to a method of decreasing the amount of respiratory distress of the mammal during a feeding period, to a method of feeding the ruminant, to a mammal ration, to a daily mammal ration, to a method of feeding mammals an animal feed that contains resistant starch, and to a method of increasing the feed efficiency of a mammal during a feeding period that entails feeding the mammal an effective amount of a fluid animal feed during the feeding period and feeding the mammal an effective amount of resistant starch during the feeding period.