The present invention relates to dissolvable containers for animal feed micro-ingredients, and methods for using such dissolvable containers to prepare an animal feed mixture. Ingredients required in very small amounts with respect to the rest of the components in an animal feed, i.e., micro-ingredients, can be pre-measured and sealed within the dissolvable containers, which can be made from a water-soluble polymer film, then added to the other feed components when the complete animal feed is being prepared.