Previous research conducted on bulls, rats and man have shown that selenium-deficient animals produce less viable semen than animals of an adequate status, because the tail of the spermatozoa is a seleno-flagellate (Slaweta et al., 1988). Furthermore, the fertilising ability of ram spermatozoa is reduced in liquid nitrogen as the semen quality is affected by osmolality and the freezing and thawing process (Colas and Guerin, 1981). In a small experiment, the effect of selenium supplementation on low-selenium rams was tested to ascertain the quality and viability of fresh ram semen and the post-thaw recovery and fertilising ability of frozen semen.