Cryopreservation of buffalo (Bubalus bubalis) semen: Current status and future prospective

Abstract

Most progress in improving reproductive efficiency of buffalo can be made by accurate estimation of the fertility of males and their selective use. Because of the major impact of individual males on multiple pregnancies and the ability to estimate fertility of males, more emphasis is placed on evaluating males. Spermatozoa were the first mammalian cells to be cryopreserved successfully due to the serendipitous discovery of the cryoprotective effect of glycerol. The development of cryopreservation protocols for the bull to be used for AI in the dairy industry began in the 1950s. Cryopreservation of semen has permitted the rapid expansion of reproductive technology such as artificial insemination. Advances in the reproductive biotechnology particularly cryopreservation of semen paved the way for better freezing of buffalo semen which was earlier considered as problematic. However, cryopreservation induces damage to all sperm compartments. Moreover, there is also variable degree of morphological, physiological and biochemical alterations in remaining population of live spermatozoa making them unsuitable for optimum fertility. Till today, there is no single objective test to evaluate the fertility of bull. The development of fertility markers to identify bulls of high breeding values at young age represents a remarkable way for achieving genetic gain in dairy farming. This review summarizes the developmental path of semen cryopreservation in buffalo along with the recent development in this field and critical gap therein.