A method is provided for encapsulating sperm in a particle wherein the particle provides for the timed release of the sperm. In particular, the method uses a gel forming polymer to form the particle and a medium for maintaining most of the sperm in a non-capacitated stage while it is encapsulated. Further provided is a method for artificial insemination using the encapsulated sperm wherein the sperm is naturally or artificially capacitated after the artificial insemination. In an embodiment, capsules containing a core of sperm in a semen extender are formed as a mixture having membranes of different thicknesses to provide varying time of sperm release. In another embodiment, the sperm and extender are dispersed throughout solid beads that vary in chemical property and diameter to provide varying time of sperm release. The extender may be free of glucose, xanthine oxidase and H.sub.2 O.sub.2, and contain fructose, fructose-6-phosphate, pyruvate, lactate or mixtures thereof as a carbohydrate source.