Importance of L-carnitine as Biochemical Marker for Semen Quality Preservation after Cryopreservation in Stallions

The aim of this work is to study the significance of carnitine fractions and NO metabolites for the assessment of spermatozoa resistance to cryopreservation, for which purpose these parameters were investigated in seminal plasma of animals divided according to the indices of spermatozoa of stallions subjected to cryopreservation.

There were 18 breeding stallions with an average age of 11.28±5.46 years, all 18 were of Arabian breed. Using cluster analysis of indicators of semen quality, animals were identified into two groups: with high and low sperm resistance to cryopreservation-thawing. We assessed standard quality parameters in fresh and cryopreserved sperm, as well as carnitine and its fractions and NO metabolites in stallions’ seminal plasma, steroid hormones level and carnitine fractions in blood serum. Data were analyzed using JASP. Differences at p<0.05 were considered statistically significant.

Seminal plasma obtained from animals from the cluster with low motility after cryopreservation-thawing was characterized by a lower concentration of nitric oxide metabolites in 1,79 time (p=0.0415) and free carnitine in 1,64 time (p=0.0349). Positive moderate strength correlation were established between the level of seminal plasma free carnitine and the percentage of live spermatozoa after sperm cryopreservation-thawing.