Study on the Effect of Method of Bull Semen Collection upon Several Qualitative Parameters of Fresh and after Thawing of Semen
University of Forestry, Faculty of Veterinary Medicine, BG-1605 Sofia, Bulgaria
PARVANOV, P., 2000. Study on the effect of method of bull semen collection upon several qualitative parameters of fresh and after thawing of semen. Bulg. J. Agric. Sci., 6: 233-237
A total of 160 bull ejaculates have been collected – 68 (70.83%) in an artificial vagina and 92 (95.83%) by electroejaculation. The volume of semen obtained by the latter method was twice bigger than that collected in the artificial vagina (6.40 ± 0.86 cm3 vs 3.10 ± 0.31 cm3). The values for spermatozoa concentration were significantly lower in electroejaculates compared to those in the artificial vagina (71.6 ± 1.17 millions vs 121.0 ± 0.87 millions). The mobility of spermatozoa, with both straight and advancing movements was not significantly different for both methods after the collection (2.1% higher in the artificial vagina) while in after thawing of semen the percent of mobile spermatozoa was significantly higher by 5.1% in the artificial vagina compared to electroejaculation.
When the first ejaculate was collected by electroejaculation and the second – in the artificial vagina, the total spermatozoa counts were significantly lower (188.1 ± 2.92 millions for electroejaculation and 134.8 ± 1.98 millions for the artificial vagina).
Key words: bull, artificial vagina, electroejaculation, spermatozoa