Abstract: A controlled release delivery device for macromolecular proteins which comprises a water-soluble outer capsule completely surrounding an inner compartment containing a plurality of non-uniform beadlets. The beadlets comprise a rupturable wax shell which completely surrounds a core matrix containing the macromolecular proteins and optional "core agents" such as excipients, stabilizers, binders, surfactants, preservatives, or mixtures thereof, and the like.The water-soluble outer capsule dissolves when the device is administered to an animal and simultaneously exposes substantially all of the beadlets to an aqueous environment. Each beadlet absorbs fluid from the environment and separately ruptures over a prolonged period thus delivering the macromolecular protein to the animal.

Abstract: Muscle quality of pigs normally susceptible to porcine stress syndrome is improved by administering to the pigs in conjunction with their daily feed ration, a small amount of porcine somatotropin.

Abstract: Somatotropin is administered to food producing animals in the finishing stage of growth to increase fertility by increasing embryonic survival and litter size during the reproductive stage of growth.