Effects of alpha1-adrenoceptor antagonist (tamsulosin) on incident of ejaculation and semen quality in the goat.

Male temporary contraception is occasionally required in some animals. Alpha1-adrenoceptor antagonist (tamsulosin) can cause ejaculation disorder. Two sets of Latin square were applied to six male goats to received either normal saline, dimethylsulphoxide or tamsulosin (179.8 nmol kg(-1) ) at 1-week interval. Semen collection and libido scoring were undertaken at 3, 6 and 24 h post-injection. For ejaculated semen, its quality was evaluated. Physiological measurements including body temperature, respiration and heart rates were measured before injection and at 30 min before semen collection. The results showed that libido score and physiological changes were not affected by treatments and time periods. Anejaculation was observed in 11 (91.7%), 5 (41.7%) and 1 (8.3%) males at 3, 6 and 24 h post-tamsulosin injection respectively. The incidence returned to normal when compared with control groups at 24 h. The percentages of motile and live spermatozoa at 6 h post-tamsulosin injection were significantly lower (P < 0.05) than that of normal saline group. At 24 h post-injection, there were no significant differences of all semen parameters among treatments. This study demonstrated that tamsulosin had temporary effects on ejaculation and semen quality without reducing sex desire and physiological functions in male goats.