This study aimed to identify and characterize the sperm subpopulations existing in water buffalo semen using a computer assisted sperm analyzer （CASA）, as well as assess the effects of cryopreservation on the sperm ...This study aimed to identify and characterize the sperm subpopulations existing in water buffalo semen using a computer assisted sperm analyzer （CASA）, as well as assess the effects of cryopreservation on the sperm subpopulation structure and evaluate bull variability. The semen of eight Bulgarian Murrah bulls was collected by four times in an interval of one week each. The semen was cryopreserved following a standard protocol and sperm kinematics was assessed. Clustering methods were applied to individual sperms, forming two significantly different （P 〈 0.05） subpopulations （P1 and P2）. Subpopulation P1 represents those spermatozoa that moved most rapidly and progressively （46.29%）, and subpopulation P2 includes spermatozoa with relatively low velocity or poorly motile but with high progressiveness （53.41%）. There was a decline on the population of P1 sperms from fresh （52.52%）, pre-freeze （45.73%） to post-thaw （35.17%） stages and significant difference on the sperm kinematics between P1 and P2. A significant decline in the values of distance, velocity and amplitude of lateral head （ALH） parameters were observed at post-thaw stage, while an increase was observed on trajectory and beat cross frequency （BCF） kinematics. Values of sperm kinematics were also significantly different （P 〈 0.05） among all bulls. The frequency distribution of spermatozoa on both subpopulations P1 and P2 was quite similar for all bulls in pre-freeze and post-thaw stages, but with significant （P 〈 0.05） variability on fresh stage. Bulls with the highest maintained frequency of P1 sperms are denoted as good freezer bulls. In sum, kinematic characterization of water buffalo sperm and clustering into subpopulation enable to identify bulls that are more resistant to cryopreservation and production of quality semen for genetic propagation.展开更多
Due to the small volume of goat semen ejaculate, just a few doses of goat semen were produced when the sperm concentration is 100 × 10^/mL. The study was aimed to determine the viability of extended goat semen at...Due to the small volume of goat semen ejaculate, just a few doses of goat semen were produced when the sperm concentration is 100 × 10^/mL. The study was aimed to determine the viability of extended goat semen at refrigerated condition at 5 ℃ using varying sperm concentrations and evaluated if sperm concentration lower than 100 × 10^6/mL would affect the motility, viability and sperm morphology at refrigerated condition. Using an artificial vagina, ejaculated goat semen was collected from goat semen donor aged 1.5 year. Physical evaluation of the collected semen showed an average volume of 0.54 mL, mean pH of 6.8 and a milky white color with thick consistency indicative of high concentration. Fresh goat semen had an initial average of 76% with an average initial sperm concentration of 128 × 10^/mL. The semen was divided into four treatments： sperm concentration of 100× 10^/mL, 75 × 10^/mL, 50 × 10^/mL and 25 × 10^/mL, and were stored at 5 ℃ for a period of 10 d. The semen evaluation was performed for each of the four treatments every other day. Results showed that the sperm concentration of spermatozoa affected the duration of storage based on the sperm motility percentage, viability and morphology of spermatozoa. The extended goat semen with sperm concentration of 25 and 50 million sperm/mL is optimal for storage within 6 d that gave satisfactory percentage motile, viable and morphologically normal spermatozoa.展开更多
文摘This study aimed to identify and characterize the sperm subpopulations existing in water buffalo semen using a computer assisted sperm analyzer （CASA）, as well as assess the effects of cryopreservation on the sperm subpopulation structure and evaluate bull variability. The semen of eight Bulgarian Murrah bulls was collected by four times in an interval of one week each. The semen was cryopreserved following a standard protocol and sperm kinematics was assessed. Clustering methods were applied to individual sperms, forming two significantly different （P 〈 0.05） subpopulations （P1 and P2）. Subpopulation P1 represents those spermatozoa that moved most rapidly and progressively （46.29%）, and subpopulation P2 includes spermatozoa with relatively low velocity or poorly motile but with high progressiveness （53.41%）. There was a decline on the population of P1 sperms from fresh （52.52%）, pre-freeze （45.73%） to post-thaw （35.17%） stages and significant difference on the sperm kinematics between P1 and P2. A significant decline in the values of distance, velocity and amplitude of lateral head （ALH） parameters were observed at post-thaw stage, while an increase was observed on trajectory and beat cross frequency （BCF） kinematics. Values of sperm kinematics were also significantly different （P 〈 0.05） among all bulls. The frequency distribution of spermatozoa on both subpopulations P1 and P2 was quite similar for all bulls in pre-freeze and post-thaw stages, but with significant （P 〈 0.05） variability on fresh stage. Bulls with the highest maintained frequency of P1 sperms are denoted as good freezer bulls. In sum, kinematic characterization of water buffalo sperm and clustering into subpopulation enable to identify bulls that are more resistant to cryopreservation and production of quality semen for genetic propagation.
文摘Due to the small volume of goat semen ejaculate, just a few doses of goat semen were produced when the sperm concentration is 100 × 10^/mL. The study was aimed to determine the viability of extended goat semen at refrigerated condition at 5 ℃ using varying sperm concentrations and evaluated if sperm concentration lower than 100 × 10^6/mL would affect the motility, viability and sperm morphology at refrigerated condition. Using an artificial vagina, ejaculated goat semen was collected from goat semen donor aged 1.5 year. Physical evaluation of the collected semen showed an average volume of 0.54 mL, mean pH of 6.8 and a milky white color with thick consistency indicative of high concentration. Fresh goat semen had an initial average of 76% with an average initial sperm concentration of 128 × 10^/mL. The semen was divided into four treatments： sperm concentration of 100× 10^/mL, 75 × 10^/mL, 50 × 10^/mL and 25 × 10^/mL, and were stored at 5 ℃ for a period of 10 d. The semen evaluation was performed for each of the four treatments every other day. Results showed that the sperm concentration of spermatozoa affected the duration of storage based on the sperm motility percentage, viability and morphology of spermatozoa. The extended goat semen with sperm concentration of 25 and 50 million sperm/mL is optimal for storage within 6 d that gave satisfactory percentage motile, viable and morphologically normal spermatozoa.
