Mehrez,, A. (2001). STUDY ON VIABILITY AND MEMBRANE INTEGRITY OF CRYOPRESERVED SPERMATOZOA OF FRIESIAN BULL UNDER DIFFERENT THAWING TEMPERATURE. Journal of Animal and Poultry Production, 26(11), 6735-6744. doi: 10.21608/jappmu.2001.258147
A. F. Mehrez,. "STUDY ON VIABILITY AND MEMBRANE INTEGRITY OF CRYOPRESERVED SPERMATOZOA OF FRIESIAN BULL UNDER DIFFERENT THAWING TEMPERATURE". Journal of Animal and Poultry Production, 26, 11, 2001, 6735-6744. doi: 10.21608/jappmu.2001.258147
Mehrez,, A. (2001). 'STUDY ON VIABILITY AND MEMBRANE INTEGRITY OF CRYOPRESERVED SPERMATOZOA OF FRIESIAN BULL UNDER DIFFERENT THAWING TEMPERATURE', Journal of Animal and Poultry Production, 26(11), pp. 6735-6744. doi: 10.21608/jappmu.2001.258147
Mehrez,, A. STUDY ON VIABILITY AND MEMBRANE INTEGRITY OF CRYOPRESERVED SPERMATOZOA OF FRIESIAN BULL UNDER DIFFERENT THAWING TEMPERATURE. Journal of Animal and Poultry Production, 2001; 26(11): 6735-6744. doi: 10.21608/jappmu.2001.258147
STUDY ON VIABILITY AND MEMBRANE INTEGRITY OF CRYOPRESERVED SPERMATOZOA OF FRIESIAN BULL UNDER DIFFERENT THAWING TEMPERATURE
Animal Production Research Institute, Agriculture Research Center, Ministry of Agriculture, Egypt.
Abstract
The effects of different thawing temperatures (37oC for 30 second and 20oC for 60 second) on viability and membrane integrity of cryopreserved spermatozoa with different hypoosmotic conditions (50, 100, 150, 200 and 300 mOsm) and incubation times (0, 15, 30, 45 and 60 min) at the same temperature of thawing using frozen semen were studied on semen from five Friesian bulls. Results showed that immediately after thawing sperm motility (58% vs. 62%), grade of motility (3.3 vs. 3.7) and sperm livability (76 vs. 84%) and abnormality (3.6 vs. 5.2%) improved (P<0.05) in spermatozoa determined immediately after 37oC than 20oC thawing temperature. However, percentage of spermatozoa with intact acrosome did not differ significantly (73.6% vs. 79%). Pearson’s correlation coefficients between different sperm characteristics of thawed semen revealed a positive correlation between sperm motility percentage and each of, grade of motility and sperm livability, and between sperm livability and grade of motility. Such correlations were significantly (P<0.05) for stronger semen thawed at 37oC (r=0.92, 0.94 and 0.91, respectively) than those at 20oC (r=0.41, 0.73 and 0.80, respectively). Correlation coefficient between percentage of sperm motility and abnormality was negative, although it was significant (P<0.05) and strong in semen thawed at 20oC (r=-0.88) than in those thawed at 37oC (r=-0.23).
Sperm viability (percentage and grade of motility) showed significant (P<0.05) reduction from 300 up to 100 mOsm in both thawed semen, but the differences between the two thawed semen were not significant at all osmolarity levels. However, percentage of curled spermatozoa significantly (P<0.05) increased by decreasing the osmolarity level from 300 up to 100 mOsm for semen thawed at 37oC and up to 50 mOsm for those thawed at 20oc. Yet, the percentage of curling was significantly higher in semen thawed at 37oC than 20oC at all osmolarity levels.
On the other hand, sperm viability decreased by increasing incubation time in both thawed semen showing significantly (P<0.05) the minimal values of grade of motility (1.80) at 60 min for 37oC thawing and at 15 min for 20oC thawing (1.84). While, motility percentage was reached their minimal values at 45 min in both thawed semen. However, the differences between both thawed semen were not significant. The percentage of curled spermatozoa increased significantly (P<0.05) by advancing incubation time up to 45 min in both thawed semen, but its values were always significantly higher in semen thawed at 37oC than those thawed at 20oC.
The correlation coefficient between percentage of curled spermatozoa and each of sperm motility, livability and intact acrosome percentages was significantly positive and stronger in semen thawed at 37oC than that at 20oc.
The current study, indicate that thawing at 37oC for 30 sec results in better sperm quality in terms of high sperm viability and membrane integrity (reactivity to hypoosmotic swelling test, HOS- test).