Evaluation of the effect of adding cysteamine on Ros 308 sperm quality parameters and reduction of lipid peroxidation rate during freezing-thawing process

Introduction: Long-term storage of semen is essential for achieving the benefits of artificial insemination (Tuncer et al. 2010). This is carried out by sperm cryopreservation, which stops the sperm metabolic activities, allowing long storage (Bailey et al. 2000). This process affects the sperm quality (Wang et al. 1991) by introducing mechanical and chemical damage, production of reactive oxygen species, oxidative stress, and reducing antioxidant activity (cysteamine is an aminothiol antioxidant as an effective scavenger). Cysteamine is known to have been reported in some studies to improve the freezing of ram sperm (Bucak et al. 2007). The aim of the present study was to determine the antioxidant effects of cysteamine on the functional parameters of cysteamine in Lake Extender based on soybean lecithin. Material and methods This study was carried out in University of Tabriz research station. For this purpose, 15 adult roosters (25 weeks old) were used. Sperm collection was done by dorsal-abdominal massage. The roosters were habituated for one month and sperm collection was performed twice a week. First, sperm were examined for volume, concentration and color, and only samples with volume of 0.2 to 0.7 mL and motility ≥80% and concentration above 3×109 were used. To eliminate the individual effects, the confirmed samples were pooled. Four levels containing control, 0.15, 0.30, and 0.45 μM cysteamine were then added to Lake Extender containing (one part of semen and four of extender). The cooling process was carried out in two steps. The samples were adjusted to 4°C for two hours. Samples were transferred to the refrigerator for one more hour, then they were drawn into 0.25 mL straws, placed 4 cm above nitrogen vapor for 7 min, and immersed in liquid nitrogen. They were stored in liquid nitrogen until further analysis. For assessment, the cryopreserved straws were thawed in a water bath at 37 °C for 30 s. The motility parameters were evaluated using CASA, viability by Eosin-Nigrosin staining, membrane integrity by Host tests, sperm abnormality by Hancock test and lipid peroxidation by MDA. Results and discussion: Based on the results (Table 2), addition of 30 and 0.45 μM significantly increased total motility and 0.30 μM level improved progressive motility, VAP, VSL and VCL parameters (P