Effect of selenium and vitamin E addition to the extender on liquid stored capercaillie (Tetrao urogallus) semen quality
Captive breeding has become an important tool in species conservations programmes, maintaining genetic diversity and restoring wild, endangered populations. In order to improve the reproductive efficiency of captive kept capercaillie, the purpose of the study was to determine the effect of selenium and vitamin E addition to semen extender on sperm characteristic during short-term storage. Ejaculates collected individually from four capercaillie were divided into two parts, diluted threefold with basic EK extender and EK enriched with 1 mg/ml of organic selenium and 8 mg/ml of vitamin E (EK+Se+E) and stored 24 hr at temp. +4°C. Spermatozoa morphology, motility and motility parameter were evaluated in net, diluted and stored semen samples. Significant (p < .05) differences between individual males were stated in relation to the majority of traits evaluated in the freshly collected semen. Comparing to the fresh semen, a significant (p < .05) decrease in percentage of live sperm in total (by 3.8% points on average) has been observed in samples diluted by EK extender, while in semen diluted with EK+Se+E extender this decrease was lower (1.5%pts on average) and not significant. Also per cent of motile sperm in EK+Se+E extender was higher (p < .05) then in EK (71.6% vs. 58.9%), but taking into account the values of individual males, both extender and male effect on liquid semen storage become apparent. Obtained data allow concluding that selenium and vitamin E addition to EK extender had positive effect on morphology and motility of capercaillie semen stored 24 hr at 4°C and can be recommended for similar studies carried out on other Galliformes species.