Effect of age on Boujaâd ram semen quality extended in skim milk and tris egg yolk at 5°C

The aim of the present work was to study the effect of age (2.5 years vs 6 years) and extender (skim milk vs tris egg yolk) on the storage of liquid semen at 5°C. Semen was collected weekly from Boujaâd rams and extended to a final concentration of 0.8 x 109 spermatozoa/ml. Sperm quality assessment included total and progressive motility, viability, morphology, membrane integrity and lipid peroxidation assay. Sperm quality was assessed at 0, 8 and 24 hours of storage. Sperm quality decreased over time. There was a significant interaction between age, storage time and extender for progressive motility. Older rams had the significantly lower quality of sperm after storage. Skim milk preserved motility better than Tris-egg yolk. While Tris-egg yolk preserved membrane integrity and inhibited lipid peroxidation. In conclusion, the age of rams should be taken into account for artificial insemination programs using liquid stored semen. Also, type of extender should be selected based on the desired effect