Semen Evaluation of Arab Stallions during Steps of the Freezing–Thawing Protocol

Abstract

| The aim of the current study was to determine the influence of steps involved in the freezing-thawing protocol on semen quality of Arab stallions. A total of 48 ejaculates were collected (step 1) and undergone the first dilution in INRA96 ® at +37°C, followed by incubation at +22°C (step 2). A second dilution with INRA Freeze ® was carried out after centrifugation and supernatant removal (step 3). The diluted semen was kept at +4°C, then packaged in straws of 0.5 ml (step 4) and frozen into liquid nitrogen at -196°C. After 48 hours of storage, the semen was thawed (step 5). The percentages of motile sperm (%MS), abnormal head (%AH), mid-piece (%AM), flagella (%AF), cytoplasmic droplets (%CD) and abnormal sperm (%TAS) were studied at each step. Results showed that the %MS and %TAS were higher in steps 1, 2, 3 and 4 as compared to those of step 5 (p<0.05). The %AM was higher in step 5 as compared to that of the other steps (p<0.1). However, the %CD and %AF were higher respectively in the step 3 (p<0.01) and step 4 (p<0.05) than those of the other steps. Consequently, the semen quality of Arab stallions was affected during the freezing-thawing protocol. So, it is recommended to study the contribution of molecules in extenders such as vitamin C or glutamine to improve sperm motility and avoid increasing abnormal sperm during the freezing-thawing protocol.