Covers for sealing and/or bonding with an exposed surface of an animal feed within a container include a flexible film that conforms to the animal feed and a rigid or semi-rigid layer that allows the cover to be handled by an operator during placement of the cover over the animal feed composition while the composition is at elevated temperatures. The polymer film may include a heat-activated coating that establishes a bond with the animal feed when the feed is at elevated temperatures or when an external heat source is applied to the cover. The heat-activated coating may be flowable at a temperature of at least about 125° F. Upon placement of the cover over the animal feed, the film conforms to the exposed surface of the feed and the cover forms a seal with the animal feed as flowable coating reaches a flowable temperature.