Preparation of Targeted Delivery Materials and Their Application in Animal Production

In livestock production, conventional nutrients and bioactive substances are susceptible to degradation during feed processing, storage, and gastrointestinal transit, resulting in low bioavailability and feed conversion efficiency. Targeted delivery technology, which utilizes carriers such as nanoparticles, microcapsules, and hydrogels, can protect these compounds from premature degradation, regulate their release kinetics, and achieve site-specific accumulation via various administration routes, including oral and injectable delivery. This paper introduces the main types of targeted delivery materials and their preparation methods: ionotropic gelation, emulsion solvent evaporation, and nanoprecipitation for nanoparticle fabrication; spray drying, orifice coagulation bath, ionic crosslinking, complex coacervation, and electrospinning for microcapsule production; and ionic crosslinking, gas shear-assisted ionic crosslinking, oil-in-water emulsion combined with calcium ion crosslinking, and enzymatic crosslinking for gel-based system synthesis. Evaluation methods are also described in detail, covering particle size and polydispersity index analysis, morphological characterization, in vitro simulated digestion, and in vivo fluorescence imaging. This paper reviews the applications of this technology in poultry, pigs, and ruminants, with emphasis on its roles in enhancing intestinal health, regulating immune responses, inhibiting pathogenic bacteria, and improving growth performance and product quality, aiming to provide theoretical references for the rational design and application of targeted delivery systems in precision animal nutrition and sustainable livestock production.