[Morphology of live and dead spermatozoa of stallions (author's transl)]

Examination of 539 ejaculates of stallions of various breeds showed that approximately 60 per cent of the spermatozoa were completely normal morphologically. Of these morphologically normal spermatozoa, 13 per cent were dead. The total proportion of live spermatozoa was 75 per cent, 32 per cent being obviously abnormal (22 per cent of live and 10 per cent of dead spermatozoa). Separated heads (normal as well as abnormal) were significantly more common among dead spermatozoa. Protoplasmic droplets (both at the neck and at the end of the middle piece) were mainly present in live spermatozoa. As the stallion grow older, the total proportion of abnormal spermatozoa shows only a slight increase. Moreover, this increase is mainly due to an increase in abnormal dead spermatozoa as the live ones show a reduction of abnormal forms. Thus, the proportions of abnormal and separated heads are reduced in live spermatozoa, whereas separated heads show a marked increase in dead spermatozoa. The total number of abnormal spermatozoa is reduced by an average proportion of 4 per cent in second ejaculates, whereas it increases by 8 per cent in live (unstained) spermatozoa.