In rabbits, the number of inseminated spermatozoa plays an important role in the fertility rate obtained after artificial insemination. However, methods for the correct determination of spermatozoa number are scarce. The aim of this study was to develop and validate a spectrophotometric method for the measurement of spermatozoa concentration corrected by the seminal particle/spermatozoa ratio. For this purpose 360 ejaculates were collected from 36 rabbit bucks. The semen samples were divided into three groups based on their particle/spermatozoa ratio subjectively determined by microscopic viewing. The spermatozoa concentration of each semen sample was evaluated by spectrophotometer and these results were compared with those obtained by using a haemotocytometer. The results of the standard spectrophotometric method were correlated with the results of the haemotocytometer count of spermatozoa (r=0.76; P<0.01). When the optical density was corrected by considering the P/S ratio, the correlation values greatly improved (r=0.94; P<0.01). The simplicity, rapidity and low cost of this method make it suitable for the routine measurement of spermatozoa concentration of heterospermic pools in rabbit artificial insemination centres.
Rabbit; spermatozoa; seminal particles; spectrophotometer