Abstract
1. The ability of domestic fowl spermatozoa to reduce MTT tetrazolium to its coloured formazan was compared with other tests of sperm quality and fertilising ability. 2. MTT reduction was highly correlated with sperm ATP content (r2=0.85); sperm mobility (r2=0.62.); sperm:perivitelline layer interaction (r2=0.80) and fertilizing ability (r2=0.83). 3. The simple, robust, MTT-reduction assay may therefore be used to select male chickens on the basis of their sperm quality and thus potential fertilising ability.