Korbetskyy A. Improving the quality of thawed dog semen by the action of membrane-stabilizing factors

The object of the project is to study physiological, biochemical and morphological processes in dog semen under influence of different membrane protecting factors in freezing extender at different stages of technological processing. The goal of the project is to evaluate structural and physiological state of the sperm plasma membranes during cryopreservation of dog semen by using membrane-stabilizing and membrane-modifying factors. Methods: physiological, biotechnological, radioimmunological, cytological, kinematic, statistical. Novelty: for the first time is shown the possibility of using substances, alternative to eggs yolk: water-soluble components of yolk, low-density lipoprotein, extract of crude sunflower oil, essentiale with bovine serum albumin, as evidenced by high level of dog semen plasma membranes protection (integrity and functionality). On the basis of the damage level of sperm plasma membranes and acrosomes by enzyme markers, revealed that egg yolk water-soluble components stabilize the structural integrity and function of plasma membrane through interaction with its components. At first scientifically approved of thiotriazoline addition to the dog freezing extender which showed high antioxidant and membrane protecting effect that significantly improves the dog spermatozoa quality parameters after thawing. Were found the most effective sugars composed of dog semen cryopreservation medium, providing high sperm quality after thawing - fructose, trehalose, sucrose and lactose. At first in Ukraine was shown the high efficiency of combined use of proline and trimethylglycine in freezing extender, showed significant increase in progressive motility, plasma membrane and acrosome integrity. Results: based on the theoretical study and experimental data was improved the extender for freezing of dog semen. It was established that the use of egg yolk water-soluble components, water extract of sunflower oil provided the sperm quality indexes at the level of whole yolk, and low-density lipoprotein and essentiale with bovine serum albumin significantly (p<0,05-0,01) increased plasma membrane and acrosome integrity of dog spermatozoa after thawing. Scientifically proofed of thiotriazoline addition to the freezing extender at concentrations of 8, 10 and 12 mg/ml, which showed high antioxidant and membrane protecting effect and significantly improved the quality indexes of dog spermatozoa after thawing. Addition of prostate fraction of ejaculate to thawed dog sperm at concentrations of 25 % provided the highest level of all studied parameters of sperm quality. Using the improved extender for sperm cryopreservation allows dog owners to get economic benefit at a rate of 4400 grn per bitch after insemination.