Evaluation of The Cryopreservation Technology of Poultry Sperm: A Review Study

Abstract

With the advancement of the poultry industry, the basic need for the use of cryopreservation technology of poultry sperms has emerged, given that it is the basic technology that preserves the genetic resources of different breeds and establishes genetic banks that in turn contribute to the establishment of different strains and lines. The technology of cryopreservation of sperm has encountered many considerations and obstacles, as the impressions of this technique are divided into three topics, the first impression believes that this technique is largely unsuccessful, while the second suggests a great potential in the preservation process. The third impression believes that cryopreservation is an encouraging and promising operation shortly. Similar to the cryopreservation of sperm in mammals, two methods were used in poultry: the slow and rapid freezing (vitrification). In both types, similar results were obtained where the fertility rates of the sperm did not exceed 40%. Due to the morphological and physiological differences between poultry and mammals’ sperms, three cryoprotectants have been widely used in poultry cryopreservation: dimethyl sulfoxide, dimethylacetamide and glycerol, glycerol is the most widely used due to its molecular properties that contribute to maintaining the highest survival rate and fertility after freezing (high permeability and low cytotoxity). The main obstacle facing this technique remains in how to treat the remaining quantities of the aforementioned cryoprotectants, which lead to a decrease in the fertility capacity after freezing and during artificial insemination. The numerous protocols used, whether in slow or rapid freezing, greatly affected fertility rates, as both the equilibrium and freezing stages played a decisive role in obtaining the highest possible rates of fertility, vitality and survivability of the sperm after thawing. It is concluded from the current review that the cryopreservation technology of poultry sperm is still in a non-advanced stage and needs many new methods to contribute to raising the fertility capacity, vitality and survivability rates after freezing.