Bichko S. Gander semen preservation depending on conditions of cryopreservation

The investigations are devoted to studying the structural and functional integrity of gander spermatozoa depending on the temperature of semen dilution with cryoprotective mixture, usage of cryoprotectants, cooling rates of the semen in straws. The express-methods for evaluation the integrity of sex cell membranes and differential staining of spermatozoa were developed for assessment the morphological state of gander spermatozoa during geese reproductive period and on different stages of cryopreservation. The method of low temperature preservation of gander semen was also developed. We diluted gander semen with the dilution B-26 with cryoprotector at 0-4C, used cryoprotective mixture N,N-dymethylformamide+1,2-propane diol (in ratio 1:2, w/w 0,9 M), plastic straws for diluted semen packing and stepping cooling rate. This method provides viability of 64% gander spermatozoa after freezing-thawing. Using the methods for investigation morphological and functional state of gander semen we proved experimentally that the physiological indices of semen, such as semen volume, spermatozoa concentration, movement and morphological integrity decreased greatly till the end of reproductive period. It was the cause of eggs fertility decreasing. It was first substantiated that usage of cryopreserved gander semen for artificial insemination of females at the end of reproductive period let obtain egg fertility at the level of 77,5% and goslings' hatchability - at the level of 60,0%.