DEVELOPMENT OF A DILUTION MEDIUM FOR SEMEN OF SMALL CATTLE

Abstract

The research was aimed at studying the effect of experimental blood plasma preparation (EBPP) in a synthetic dilution medium on the qualitative characteristics of ram semen. The semen was obtained during the mating season (October) from 3 adult rams using an artificial vagina. 24 ejaculates were obtained. With each collection, the ejaculates were combined to exclude the influence of the individual characteristics of the ram and divided into 4 equal parts. Then, one part was diluted with synthetic TRIS-based medium (control), and three aliquots with the same medium supplemented with different proportions of EBPP (5%, 10% and 15%, respectively). In the end there were 4 groups. All samples were subsequently cryopreserved in liquid nitrogen. We studied the general motility, speed of sperm cells movement, integrity of the acrosome and plasma membrane of sperm cells at different stages of cryopreservation (dilution, equilibration and after freezing-defrosting).

The results showed that semen, which was supplemented with 10% EBPP had significantly higher overall motility (P < 0,05) compared to the control and other groups after equilibration and in frozen-thawed semen. In addition, in sperm supplemented with 5% and 10% EBPP, the percentage of fast-moving sperm cells increased significantly (P < 0,05) compared to the control group and 15% EBPP group after equilibration and freeze-thawing. The addition of 10% EBPP resulted in improved progressive semen motility and viability after cryopreservation (P < 0,05), as well as increased acrosome preservation and plasma membrane integrity in comparison to the control. In conclusion, it was noted that the addition of EBPP improved the cryoresistance of ram sperm in general, which allowed us to predict a higher fertilizing ability of cryopreserved semen due to improved quality parameters.