The quality and fertilizing ability of sperm after the addition of nanosuccinates of Mn, Cu, Zn to the medium for cryopreservation of ram sperm

Abstract

In the process of cryopreservation of sperm, there are violations of the ultrastructure of spermatozoa, which causes biochemical and functional changes in them. To protect spermatozoa from the negative effects of low temperatures, cryopreservation media are used, to which trace elements are added. Recently, nanoforms of trace elements have been obtained in Ukraine and experiments have been started to study their effect on the animal body. The aim of the work was to find out the effect of adding nanosuccinate of Mn, Zn and Cu to the medium for cryopreservation of ram sperm on the quality and fertilizing ability of sperm. The experiment was conducted on six clinically healthy breeder rams, aged 2–4 years. After evaluating the ejaculate from six rams aged 2–4 years, the Texel breed was divided into control and experimental groups. Control sperm samples were diluted with lactose-yolk-tris-citrate-glycerin medium (LYTCGM). Nanosuccinates of microelements were added to the medium in test samples of ram sperm in the following doses: Zn and Mn – 2.5, 5.0 and 7.5 μg/l, Cu – 1.25, 2.5 and 3.75 μg/l. Diluted sperm was packaged in straws, equilibrated for 2.5 hours and frozen. After thawing of sperm, motility, percentage of damaged spermatozoa, their survival, activity of succinate dehydrogenase (SDH) and cytochrome oxidase (CO) in sperm were determined. A dose-dependent effect of Mn, Zn, and Cu nanocitrates upon their addition to LYTCGM was established. The addition of Mn and Zn nanosuccinate at a dose of 5.0 μg/l to LYTCGM probably increases the motility of ram spermatozoa after thawing, and also reduces the percentage of spermatozoa with morphological disorders. Addition of Cu nanosuccinate in increasing doses significantly reduces spermatozoa motility in thawed ram semen, simultaneously increasing the percentage of degenerate spermatozoa. After the addition of Mn and Zn nanosuccinate at a dose of 5.0 μg/l LYTCGM, the survival rate of ram spermatozoa is probably increased, and the addition of Cu nanosuccinate in increasing doses significantly reduces the survival time of germ cells. Addition of Mn and Zn nanosuccinate at a dose of 5.0 μg/l to LYTCGM probably increases the activity of SDH and CO in sperm after thawing, and the addition of Cu nanosuccinate in increasing doses significantly reduces the activity of these enzymes. The addition of Mn and Zn nanosuccinate in lower (2.5 μg/l) and higher (7.5 μg/l) doses did not significantly affect the motility, morphological disorders and survival of spermatozoa, as well as the activity of SDH and CO in them.