Over the last few years, effect of various concentrations of melatonin on semen preservation was studied in domestic animals and seasonal variation in melatonin production and its effect on semen production, quality were also studied. Melatonin is used as an antioxidant in semen preservation in the present study at various concentrations. Moreover, seminal parameters with various antioxidant and biochemical profiles were studied at different concentrations and at different seasons. Addition of this additive on semen preservation will improve the conception rate and reduces the repeat breeding through better semen preservation. Melatonin helps to select the suitable season to collect the semen to improve the semen preservability. This book will help to the breeders and farmers to improve the fertility in artificial breeding centres and enhance reproductive performance in cost effective manner.