Effects of different extenders on the short-term storage of Southern Karaman rams semen

The conservation of native sheep breeds, the preservation of genetic diversity and the provision of sustainable livestock production are of great importance. The aim of this study was to determine the short-term storage viability of semen collected from Southern Karaman rams, one of Türkiye native sheep breeds at risk of extinction, using two different extenders. A total of six rams were used. Since the animals could not be trained to use an artificial vagina, semen was collected using an electro-ejaculator during the breeding season. The semen samples collected were diluted with an extender containing Tris-egg yolk and a liposome- based extender (OptiXcell®, IMV Technologies, France) and stored at 4°C. Spermatological parameters such as motility, viability and morphological characteristics were evaluated at 0 and 96 hours (h). In addition, some biochemical parameters were examined, primarily changes in malondialdehyde levels, which are considered an important indicator of oxidative stress and antioxidant enzyme levels. The results showed that the type of extender had no statistically significant effect on spermatological parameters. However, significant changes in these parameters were observed during the storage period. The interaction between types of extenders and storage time was not found to be statistically significant. At 96 h, malondialdehyde levels in semen were significantly higher in both extenders compared to 0 h values, while reduced glutathione levels and catalase activity showed a significant decrease. These findings suggest that both extenders can be used for the short-term storage of ram semen without significant differences in spermatological parameters, although storage duration remains a critical factor affecting sperm quality and oxidative stability.