Abstract: Disclosed are compositions, kits, and methods for enhancing growth in an animal in need thereof. The methods typically comprise administering orally to the animal a composition comprising biodegradable particles, the biodegradable particles comprising a polymer or a co-polymer comprising polymerized lactic acid and having an effective average diameter of 0.5-5 ?m. In the methods, the animal is administered a dose of the biodegradable particles that is effective for improving feed conversion rate in the animal in comparison to an animal that is not administered the composition.

Abstract: Disclosed are compositions, kits, and methods for enhancing growth in an animal in need thereof. The methods typically comprise administering orally to the animal a composition comprising biodegradable particles, the biodegradable particles comprising a polymer or a co-polymer comprising polymerized lactic acid and having an effective average diameter of 0.5-5 ?m. In the methods, the animal is administered a dose of the biodegradable particles that is effective for improving feed conversion rate in the animal in comparison to an animal that is not administered the composition.

Abstract: Disclosed are compositions, kits, and methods for improving feed conversion rate in an animal in need thereof. The methods typically comprise administering orally to the animal a composition comprising biodegradable particles, the biodegradable particles comprising a polymer or a co-polymer comprising polylactide (PLA) and having an effective average diameter of 0.5-5 ?m. In the methods, the animal is administered a dose of the biodegradable particles that is effective for improving feed conversion rate in the animal in comparison to an animal that is not administered the composition.

Abstract: Disclosed are compositions, kits, and methods for inducing an immune response against an infection or a disease. The compositions typically include biodegradable particles having an average effective diameter that such that the biodegradable particles are phagocytosed by antigen presenting cells when the biodegradable particles are administered to a subject in need thereof. Optionally, the compositions include one or more of an adjuvant, an apoptosis inhibitor, and an antigen. The compositions, kits, and methods may be utilized to induce a cell-mediated response, such as a T-helper cell response, and/or a humoral response against a pathogen or a disease. In some embodiments, the compositions, kits, and methods may be utilized to induce preferentially a Th1 response versus other types of immune responses such as a Th2 response.

Abstract: Disclosed are compositions, kits, and methods for inducing an immune response against an infection or a disease. The compositions typically include biodegradable particles having an average effective diameter of 0.5-20 ?m, and optionally the compositions include one or more of an adjuvant, an apoptosis inhibitor, and an antigen. The compositions, kits, and methods may be utilized to induce a cell-mediated response, such as a T-helper cell response, and/or a humoral response against a pathogen or a disease. In some embodiments, the compositions, kits, and methods may be utilized to induce preferentially a Th1 response versus other types of immune responses such as a Th2 response.