Artificial insemination (AI) in cattle is popular in world wide. But AI in pig is not yet common in field condition in most of the developing countries. To achieve successful AI, preservation of semen is a prerequisite. There are several methods of processing and preservation of semen either in liquid or frozen state meant for AI. However, no single technique has been approved as the ideal so far. Like wise difference in timing of AI also differ fertility and fecundity in pigs. Further research in this field is highly recommended to develop a suitable technique. This book discusses about boar reproductive performance with respect to libido and sperm characteristics before and after preservation. Performance of AI was also appraised by using best processed and preserved semen in this research. Hope it will be useful for the students and research scholars in pig reproduction as well as those who are involved in pig production for livelihood and R&D professionals engaged in rural development.