Effect of storage time on the quality of cauda epididymal spermatozoa of West African dwarf (WAD) rams.

The objectives of the study were to develop a protocol for preserving Western African Dwarf (WAD) ram cauda epididymal semen that could be applied in preserving and storing the semen of endangered species/genetically valuable animals in case of death and to study the morphometric characteristic of epididymides after refrigerated storage. Thirty testes-epididymides were collected immediately after slaughter from mature WAD rams and transported in ice chest at (4.5-6 °C) to the laboratory. The samples were either processed immediately or stored in a refrigerator at 5 °C for 6, 12, 24, 48 h. The results indicate that the semen motility decreased (P <  0.05) when compared to the control [87.5 ± 2.1% (0 h), to 85.0 ± 1.8% (6 h), 73.3 ± 3.6% (12 h), 53.3 ± 2.5% (24 h) and 50.0 ± 2.9% (48 h)]. The sperm concentration also decreased (P <  0.05) as duration of storage increased (0 h) 157.5 ± 8.2, (6 h) 152.3 ± 5.8, (12 h) 125.3 ± 4.4, (24 h) 106.2 ± 2.9, (48 h) 98.5 ± 3.5. Semen viability decreased as duration of storage increased from the 0 h to 48 h [(P <  0.05; 84.0 ± 1.4%, 82.8 ± 2.2%, 77.3 ± 1.7%, 69.8 ± 1.5%, and 66.5 ± 1.2%, respectively]. Furthermore, there was a decrease (P <  0.05) in percentage of intact acrosome as duration of storage increased [(0 h) 90.7 ± 1.0%; (6 h) 89.3 ± 2.0%; (12 h) 85.5 ± 1.6%; (24 h) 70.0 ± 2.4%; and (48 h) 73.3 ± 2.1%]. The results from this study indicate that epididymal semen of WAD rams recovered and preserved at 5 °C for 48 h may be used for artificial insemination.