The purpose of this study was to establish an optimal storage temperature and characteristic analysis after frozen-thawed dairy goat sperm. Sperm was collected at Chojeong dairy goat farm using an electric stimulator and dilluted with semen washing media. The egg yolk-triladyl frozen solution was used for the freezing of Saanen dairy goat sperm and the freezing concentration was set to 1×108sperm/ml. The frozen sperm were thawed in water bath at 37.5℃ for 45 seconds and motility was measured after preservation for 0, 30, 60, 90 and 120 min at 4℃, 17℃ and 37℃, respectively. Sperm characteristic analysis was conducted by flow cytometry. In results, sperm motility at 30, 60, 90 and 120 min after thawing was significantly higher in 17℃ than 4℃ and 37℃ (p<0.05). On the other hand, the frozen-thawed sperm motility were gradually decreased with storage periods increased (30, 60, 90 and 120 min) at 4℃, 17℃ and 37℃. Viability(42%), acrosome damage(24%), mitochondrial damage(28%) and ROS level(4%) were analyzed by flow cytometry in frozen-thawed spermatozoa in 7 male dairy goats. In summary, the motility of frozen-thawed spermatozoa in Saanen dairy goat was more efficient for storage 17℃. The average of viability 42%(30%~54%), acrosome damage 24%(16%~33%), mitochondrial damage 28%(20%~54%) and ROS level 4%(3%~6%) were arranged as standard value by 7 male dairy goats. However, more researches are needed to establish the optimal conditions or proper supplementation for sperm preservation. This study was carried out with the support of research project on feasibility study of the research & development projects for activating the hillside livestock farming and the development of goat grazing program of Rural Development Administration by Korea government (2018PJ013546).

During the freezing and thawing process, fatty acids in the plasma membrane of sperm are released, which results in a functional damage of sperm. Sperm with functional loss due to cryo-damage result in a decrease in fertility. Previous studies have shown that the addition of one of the fatty acid alpha-linolenic (ALA) with carrier proteins improves the stability of plasma membrane and reduces the damage. In this experiment, we focused on the functional aspects of the plasma membrane of sperm and experimented with motility and morphology. For preparation of ALA-carrier protein complex, 3 ng/ml ALA was mixed with 0.7 μg/ml bovine serum albumin (BSA) or 14 ng/ml methyl-β-cyclodextrin (MBCD) in distilled water. The boar semen was purchased from GUMBO Company. Boar semen was cryo-preserved in 20% egg yolk freezing extender containing ALA, BSA, MBCD, ALA+BSA, ALA+MBCD. The frozen boar sperm was thawed at 37.5 ℃ for 45 sec in water-bath. The sperm motility and morphological abnormalities were evaluated under a phase-contrast microscope at 200 × magnification and randomly counts of 200 sperm each sample. In results, motility of frozen-thawed sperm was increased in all treatment groups. In particular, there has been significant improvement in ALA+BSA and ALA+MBCD treatment groups than control (p<0.05). However, there was no significant difference in ALA, BSA and MBCD treatment groups. Morphological normalities in frozen-thawed sperm was reduced in complex treatment groups (p<0.05). However, there was no significant difference in single treatment groups. In both motility and morphology characteristics, ALA+BSA and ALA+MBCD treatment group was higher than all treatment groups. In conclusion, the addition of ALA with carrier proteins during cryopreservation has a positive effect in its functional aspect. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Education) (2016R1D1A1B03931746).