Effect of Different Egg Yolk-Based Extenders on the Quality of Ovine Cauda Epididymal Spermatozoa during Storage at 4°C

The Influence of Three Commercial Soy Lecithin-Based Semen Extenders and Two Spermatozoa Concentrations on the Quality of Pre-Freeze and Post-Thaw Ram Epididymal Spermatozoa

There are limited studies on the factors affecting the success of ram epididymal spermatozoa (REPS) cryopreservation. On this note, the current study assessed the influence of three commercial soy lecithin-based semen extenders, AndroMed® (AND), BioXcell® (BIO), and OviXcell® (OVI), and two concentrations (400 × 106 vs. 200 × 106 spermatozoa/mL) on the pre-freeze and post-thaw quality of REPS. The REPS were retrieved from nine adult rams' testes and diluted with each of the three extenders to both concentrations. Straws were frozen manually. Standard motility (SMP) and kinematic parameters (KPs) were assessed via a CASA, while spermatozoa viability, morphology, and acrosomal integrity were assessed via the Kovács-Foote staining technique. The concentration did not significantly affect the pre-freeze and post-thaw SMP and KPs of REPS. BIO and OVI had significantly higher pre-freeze and post-thaw BCFs, post-thaw VAP, and the percentage of all intact heads than AND. In contrast, AND had a significantly lower percentage of REPS with tail defects than BIO and OVI. The 400 × 106 spermatozoa/mL concentration resulted in a significantly higher percentage of all intact heads than the 200 × 106 spermatozoa/mL concentration. Freezing significantly increased tail defects and decreased the percentage of REPS with distal cytoplasmic droplets. The cryopreservation of REPS at the 400 × 106 spermatozoa/mL concentration is recommended. All three extenders must be optimized to preserve the viability, membrane integrity, and better normal morphology of REPS; the reason for increased tail abnormality after the freezing/thawing process needs to be studied.

Idebenone improves quality of ram sperm by mitigating oxidative stress during cryopreservation

The present study was designed to test the effect of different levels of idebenone, a potent antioxidant on the quality of ram semen at post thaw. Eighteen (18) ejaculates were collected and extended with tris extender supplemented with no antioxidant (CON), with 2 μM idebenone (Id2), 5 μM idebenone (Id5), 7.5 μM idebenone (Id7.5) and 10 μM idebenone (Id10). The sperm quality was determined in terms of percent sperm motility, live sperm percentage, percent hypoosmotic swelling test (HOST) positive spermatozoa and percent intact acrosome (PIA). Moreover, malondialdehyde (MDA) level, an end product of lipid peroxidation (LPO) was also measured at post thaw both in seminal plasma and sperm cell. At post thaw, the percent sperm motility was significantly higher (p < 0.05) for Id10 as compared to Id2, Id5, Id7.5 and control. The live sperm percentage was non-significantly (p > 0.05) higher for Id10 as compared to control, Id5 and Id7.5 but significantly higher than Id2. The percent HOST positive spermatozoa was significantly higher (p < 0.05) for Id10 than control, Id2 and Id5. The MDA level in seminal plasma was significantly lower (p < 0.05) for Id10 than control and Id2. The MDA level in spermatozoa did show similar trend as in seminal plasma. Further, all the sperm parameters at all idebenone levels declined significantly from pre freeze to post thaw. In conclusion, idebenone at 10 μM level improved post thaw sperm quality by mitigating peroxidative stress, hence could be considered as a promising antioxidant additive for cryopreservation of ram semen.

Effect of washing on the post-thaw quality of cryopreserved ram epididymal spermatozoa

Aim:

The aim of the study was to evaluate the effect of washing on the post-thaw quality of ram cauda epididymal spermatozoa (P1: Unwashed, P2: Washed).

Materials and Methods:

Fresh testicles of adult healthy slaughtered rams were collected and transported to the laboratory in an ice chest, where they were weighed, and cauda epididymides were separated. These cauda epididymides were used for recovery of spermatozoa in tris-citric acid fructose buffer by incision method. Spermatozoa samples showing ≥70% progressive motility were pooled and processed further. The mean values (±standard error) of various parameters such as the percentage of sperm motility, live sperm, intact acrosome, and hypo-osmotic swelling test (HOST) reacted spermatozoa were recorded.

Results:

In this experiment, the percent sperm motility, live spermatozoa, and intact acrosome both at pre-freeze and post-thaw were higher (p>0.05) in P1 than P2. However, the post-thaw percent HOST reacted spermatozoa was slightly higher (p>0.05) for P2 than P1.

Conclusion:

Washing of cauda epididymal spermatozoa has no significant adverse effect on the quality during cryopreservation. Therefore, this processing method can be applied wherever necessary before the extension of the recovered spermatozoa sample in different ram extenders.