EFFECT OF THE SPERM MEMBRANE PROTECTOR ON THE FREEZABILITY OF GOAT SEMEN

Abstract

Background: Prior to freezing goat semen, it is necessary to perform seminal washing by centrifugation to eliminate Phospholipase A, with the consequent loss of elements involved in maintaining sperm functions. Objective: Determine the adequate concentration of egg yolk (YH) for freezing goat semen in a lyophilized diluent based on Tris-glucose and citric acid, without performing seminal washing by centrifugation. Methodology: ninety ejaculates were evaluated with 12 replicates, collected twice a week by means of Artificial Vagina. Volume, motility, concentration, viability and total pathologies were measured. The fit ejaculates were united and divided into five portions, each one received the corresponding diluent: Tris-glucose-Ac. Citrus with YH (2.25%, 3.37%, 4.45% and 5.65%) and the control diluent containing lactose-skimmed milk (DC). The final sperm concentration in the samples was 1.5 x 109 mL-1. The equilibrium period was carried out at 5°C for 2 h. Subsequently, it was frozen in 0.1 mL tablets in nitrogen vapors, and stored for 7 d in liquid nitrogen, thawed at 37°C and the percentages of motility (30 min, 120 min and 240 min), viability and total pathologies (30 min and 120 min) were determined. The diluents were compared using a Binary Logistic Regression model. Results: YH (4.45%) and DC had the highest probability (P <0.05) of motility at all times. The highest probability (P <0.05) of viability was for YH (4.45%), and the lowest probability (P <0.05) of total pathologies for 4.45% YH and DC, at 30 min and 120 min. Implications: In the freezing of goat semen, it is possible to eliminate the seminal washing process by centrifugation. Conclusion: Goat semen can be frozen in a Tris-based lyophilized extender with 4.45% egg yolk, without performing seminal washing by centrifugation.