The invention is designed to enhance mammalian reproduction and in particular to improve the use of existing artificial insemination catheters in combination with novel products and processes for the insemination of mammals such as pigs. The invention comprises a controlled/sustained release delivery system comprising a metabolite/carrier combination based on specific gels, polymers and/or other molecular complexes for metabolite delivery at the point of insemination en order to promote aspects of spermatozoa function.
