QUALITY OF DECONSERVED BULL SPERM AFTER ADDITION OF MICROELEMENTS CONNECTED TO N-DERIVATIVE PEG400 TO DILUENT

Abstract

The aim of the work was to establish optimal regimes for sperm cryopreservation when using nano-complexes in environments. The effect of micronutrients (Сu2+, Zn2+, Mn2+) in the polymer- transporters on the survival and fertilization capacity of sperm bulls was investigated. To assess the validity of the complexes N-derivative PEG400, ejaculates were chosen with volume – from 2 to 5 ml, concentration - 0,7 - 1,2×109 cells/ml and sperm activity 7.0 - 8.0 points. Sperm diluted with lactose-yolk-glycerin diluent was divided into parts: control - without addition and experimental with the addition of N-derivative PEG400 (N-PEG400) with a content of 1 ml of solution: Zn2+ - 0,0319 mmol; Cu2+ - 0.0222 mmol; Mn2+ – 0.0359 mmol. In the test sperm samples were added 0.01 ml of solutions of microelements in the polymer composition in ml of diluted ejaculate. Sperm survival was determined in sperm survival samples, motility, respiratory activity, activity of enzymes-markers of sperm fertility - succinate dehydrogenase (SDG) and cytochrome oxidase (CHO).
 It was found that the optimal equilibration time of sperm in the presence of microelements in the diluent of N-derivatives of PEG400 is 2.5 hours. In this case, the activity of sperm in the presence of N-derivatives of PEG400 depends on the exposure of spermatozoa over nitrogen vapor and the ability of trace elements to affect metabolic processes in sperm. The highest values of the values of the dynamic parameters of sperm characterized deconserved sperm with the addition to the dilution medium of Zn2+ and Mn2+ N-derivatives of PEG400 and exposure to nitrogen vapors for 8-10 minutes. It was found that Zn2+ and Mn2+ N-derivatives of PEG400 that were added in the diluent after cooled for 8-10 min over nitrogen vapor are characterized by high spermatozoa survival. The results of enzymes-markers activity show that the use of spermatozoa containing PEG400 Zn2+ or Mn2+ N-derivatives after 8-10 min exposure to nitrogen vapor, will ensure fertilization of 65% or more heifers and cows after the first insemination. Studied dose (0.01 ml of 0.0222 mmol solution / ml of diluted semen) of Cu2+ N-PEG400 should not be used in the diluent, when freezing the ejaculate of bulls, as the intensity of oxidative processes was elevated, which was manifested by a decrease in physiological characteristics of germ cells.