Effect of season on scrotal circumference, semen characteristics, seminal plasma composition and spermatozoa motility during liquid storage in INRA180 rams

•To study the seasonal changes in some sexual parameters of INRA180 rams.•To study the seasonal changes in the semen liquid storage of INRA180 rams.•To demonstrate that the INRA180 rams has no seasonality character.•To determine a relation between semen storage and seminal plasma cholesterol.•To determine a relation between semen storage and seminal plasma lipid.

The present study was undertaken to assess the effect of seasons on scrotal circumference, semen characteristics, seminal plasma composition, and sperm motility during liquid storage of INRA180 rams. The semen was collected from five mature INRA180 rams (2-3 years of age) during one year (from April 2014 to March 2015). Scrotal circumferences, semen characteristics, some biochemical parameters of seminal plasma were evaluated. Immediately after collection and evaluation, the semen was pooled and extended in skim milk (SM) at 15 °C to reach 0.8 × 109 spermatozoa/ml. Thereafter, samples were evaluated at different storage times (0, 8, and 24 h). The results showed that scrotal circumference, semen quality and the concentration of total protein in seminal plasma were relatively constant during the year (P > 0.05). However, total lipid and cholesterol concentrations increased significantly (P < 0.001) in winter and summer. The result showed also that progressive motility was higher in winter and summer after 24h of storage (P < 0.01). In contrast, no difference was recorded regarding total motility (P > 0.05). To conclude, the INRA180 rams have the ability to produce semen with high quality all over the year. The only parameters showing seasonal variations are cholesterol, total lipid, and progressive motility.