Innovative strategies to improve fertility of buffalo semen (original) (raw)
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Cryopreservation of buffalo (Bubalus bubalis) semen-limitations and expectations
2017
Artificial insemination with cryopreserved semen is the most viable biotechnology for faster and increased genetic improvement in many species allowing for improved herd performance and productivity. Pakistan has 34.6 million buffalo which have major share in total milk produced in the country. Rapid increase in human population and demand for animal products motivated the researchers to increase per animal milk production using this biotechnology. In buffalo, natural breeding practice is common in the country compared to artificial insemination, low fertility rate with cryopreserved semen is main hindrance in its propagation. It is need of the hour to disseminate the knowledge of various factors and components contributing in buffalo semen cryopreservation to improve milk and fertility rate of this breed.
First Commercial Semen Cryopreservation and Main Spermatological Features of Anatolian Buffalo
Livestock Studies, 2021
Conventional buffalo semen freezing studies are limited in Anatolian buffaloes, which are overly sensitive to exogenous stimulation. The present study's object was to determine the main features of Anatolian buffalo semen obtained by artificial vagina method for the first time. A total number of 150 ejaculates were collected from three Anatolian Buffalo bulls (app. 4 years of age). The mean pH, volume and concentration of semen were found 6.63±0.15, 1.61±0.5 ml, 1629±222.67 x106 spermatozoa/ml, respectively. The sperm motion characteristics were determined by using a computer-assisted sperm analysis system (CASA); the total and progressively motile sperm values were 57.12±5.63%, 23.22±4.47% and other kinetic parameters such VAP, VSL, VCL, ALH, BCF, STR, LIN were found 94.71±8.48 µm/s, 72.6±7.08 µm/s, 160.9±15.66 µm/s, 7.8±3.75 µm, 29.15±1.56 Hz, 76.91±3.87%, 46.21±2.61%, respectively after thawing. Among buffalo bulls, differences in semen pH values were statistically significan...
Andrologia, 2019
Artificial insemination (AI) in farm animals is a dynamic and the most economical reproductive biotechnology to enhance the genetic potential, reducing the risk of sexually transmissible diseases and management of calving interval to reduce the gap between demand and supply of milk (Ax et al., 2000; Eaglesome & Garcia, 1997). However, the success of AI with frozen semen primarily depends on the sperm cryopreservation technique (Wang et al., 2015). The processes of semen cryopreservation particularly (cooling, freezing and thawing) are the primary causes of cold shock, intracellular ice crystal formation and reactive oxygen species (ROS) production (Holt, Head, & North, 1992; Holt & North, 1994). All such deleterious changes encourage certain physical and functional injuries which subsequently results in the loss of viability, motility and fertilising ability of the
Journal of Agricultural Science and Technology A
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 (P 1 and P 2). Subpopulation P 1 represents those spermatozoa that moved most rapidly and progressively (46.29%), and subpopulation P 2 includes spermatozoa with relatively low velocity or poorly motile but with high progressiveness (53.41%). There was a decline on the population of P 1 sperms from fresh (52.52%), pre-freeze (45.73%) to post-thaw (35.17%) stages and significant difference on the sperm kinematics between P 1 and P 2. 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 P 1 and P 2 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 P 1 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.
Characteristics of frozen thawed semen in predicting the fertility of buffalo bulls
Information regarding the fertility index in relation to sperm attributes, which helps in the selection of future breeding bulls are meager in buffaloes. The present study was conducted to measure the differences in motility characteristics, head biometry, acrosome, plasma membrane and DNA of cryopreserved semen of fertile and subfertile buffalo bulls. The fertility of bulls was classified on the basis of conception rates (CR), where bulls having CR 28-35% and >55% were considered as sub-fertile and fertile bulls respectively. Computer assisted semen analyzer was used for motility and viability studies. Total motility, average path velocity (VAP), straight linear velocity (VSL) and curvilinear velocity (VCL) of sperm for fertile bulls were significantly higher than sub-fertile bulls. Significant differences were found in the length and width of sperm head between the 2 groups. The percentage of intactness of sperm acrosome of fertile bulls was significantly higher than sub-fertile bulls. The percentage of apoptotic sperm differed significantly between fertile and sub-fertile bulls. The sperm DNA integrity of fertile and sub-fertile bulls was not significantly different. In conclusion, the total motility, VAP, VCL, VSL, length and width of sperm head, acrosome integrity and percentage of apoptotic sperm, are useful for evaluating bulls' semen quality to reduce the risk of using semen of poor-fertility bulls in AI programme.
Animal Reproduction Science, 2001
The principal objective of this study was to derive an improved procedure for cryopreservation of swamp buffalo (Bubalus bubalis) spermatozoa. Experiments were conducted to determine effects of cooling rate, intermediate plunge temperature and warming rate on motility and acrosome integrity of spermatozoa. Spermatozoa were obtained from three bulls (three ejaculates/bull) and were subjected to nine cooling conditions before being frozen in liquid nitrogen: cooling at 10, 20, or 30 • C/min each to −40, −80, or −120 • C before being plunged into liquid nitrogen. The spermatozoa frozen under a given condition were then thawed either at 1000 or 200 • C/min. Cooling rate, intermediate temperature and warming rate significantly affected survival of spermatozoa obtained from the three bulls. Cooling spermatozoa from 4 to −120 • C either at 20 or 30 • C/min yielded better progressive motility compared to other cooling conditions (50 versus 30%). Rapid warming was superior to slow warming. In an additional study, motility and fertility of spermatozoa frozen after being cooled to −120 • C at 20 • C and 30 • C/min and those frozen by a standard protocol used routinely for semen processing were assessed. Progressive motility of cryopreserved spermatozoa cooled at 20 • C and 30 • C/min was 40%, while that of spermatozoa cryopreserved using a standard protocol was 25%. A total of 178 buffalo cows were inseminated with cryopreserved spermatozoa obtained from one bull, and their pregnancy status was assessed 60 days later by rectal palpation. Out of the 60, 26 (43%) and 23 of 58 (40%) cows inseminated with sperm cooled at 20 and 30 • C/min, respectively, became pregnant, whereas 17 of 60 (28%) cows inseminated with sperm frozen by a standard protocol became pregnant. This study demonstrates that an effective cryopreservation procedure for buffalo spermatozoa can be derived by systematic examination of various cryobiological factors.
2017
The aim of this study was to identify the sperm subpopulation structure in buffalo bulls with high and low fertility and to determine how sperm subpopulations change after semen cryopreservation. Semen was obtained from four bulls with high fertility (HF) and four bulls with low fertility (LF) and was cryopreserved. A total of 64 ejaculates were assessed for their sperm kinematics using computer assisted sperm analyzer (CASA). Ward’s Hierarchical Dendogram and K-Means clustering method were used to identify the subpopulations. In experiment 1, two significantly different (P≤0.05) sperm subpopulations were observed: Subpopulation 1 (SP1): sperms travel longer distances most rapidly and progressively, and Subpopulation 2 (SP2): sperms travel shorter distances slower but highly progressive. A higher percentage of SP1 was found in HF bulls (47.27); whereas, a higher percentage of SP2 was found in LF bulls (54.89). A low negative relationship (r=-0.18) was observed for the fertility leve...
Veterinary World, 2024
Background and Aim: The success of semen cryopreservation relies on several aspects, including breed, age, season, collection method, extender composition, cooling rate, equilibration period, freezing rate, and thawing rate. This study aimed to investigate the effects of cooling and equilibration duration, as well as the addition of antioxidants to the semen extender, on the cryopreservation of swamp buffalo semen. Materials and Methods: Semen collected from swamp buffalo bulls was subjected to four different conditions: (T1) 2-h cooling and 2-h equilibration, (T2) 1.5-h cooling and 1.5-h equilibration, (T3) 1-h cooling and 1-h equilibration, and (T4) 0.5-h cooling and 0.5-h equilibration. Spermatozoa motility was evaluated using a computer-assisted semen analyzer. Moreover, this study also investigated the effect of antioxidant supplementation during cryopreservation using tris-citrate egg yolk extenders enriched with various antioxidants: Control (Con), 1 mM melatonin (ML), 0.5 mM gamma-oryzanol (GO), 10 μM canthaxanthin (CX), 1 mM melatonin + 0.5 mM gamma-oryzanol (ML + GO), and 1 mM melatonin + 10 μM canthaxanthin (ML + CX). Results: Results showed that the (T1) 2-h cooling and 2-h equilibration and (T2) 1.5-h cooling and 1.5-h equilibration groups achieved higher progressive motility than the (T3) 1-h cooling and 1-h equilibration and (T4) 0.5-h cooling and 0.5-h equilibration groups. The ML-treated group exhibited superior progressive motility and total motility. Conclusion: The optimal approach for cryopreserving swamp buffalo bull semen involves a 1.5-h cooling period followed by a 1.5-h equilibration period, with the incorporation of ML into the semen extender. Keywords: antioxidant, cryopreservation, equilibration, semen, and swamp buffalo.
Journal of Advanced Biotechnology and Experimental Therapeutics, 2024
Abstract: Cryopreservation has been used extensively for cattle in Bangladesh, however no study was conducted on the cryopreservation of buffalo sperm in Bangladesh. Thus, the current study aimed to evaluate the suitability of different semen extenders for improving the post-thaw quality of Bangladeshi buffalo sperm under a manual cryopreservation protocol. The manual cryopreservation protocol was compared and optimized with a commercial biofreezer protocol. Then, the efficacy of different diluters was evaluated using the optimized manual cryopreservation protocol. Meanwhile, the post-thaw sperm quality in terms of motility and morphology was evaluated by computer assisted sperm analyzer during the optimization process. During manual cryopreservation, the first cooling from 37 °C to 5 °C was done in an equilibration chamber and the second cooling from 5 °C to-120 °C in a Styrofoam box using liquid nitrogen vapor from different distances (0.5, 1.5, 1.6, 2 and 3 inches). Simultaneously, another batch of sperm was cryopreserved using a programmable freezer. The highest number of motile sperms (62.67±1.12; P<0.01) and progressive motility (38.97±1.10; P< 0.001) was observed at 1.6 inches above liquid nitrogen, which were similar to the results obtained from automated biofreezer protocol (65.94±4.65 and 45.54 ± 3.64, respectively). To evaluate the semen extenders' efficacy, one locally developed Tris-fructose-egg yolk-based diluter and two commercial diluters (Andromed, and Triladyl) were used in the freezing of buffalo sperm. The highest recovery and conception rates were observed in sperm diluted with tris-fructoseegg yolk-based (TFE) (82.4% and 80%, respectively). Therefore, it is suggested that this manual cryopreservation protocol and the TFE diluter could be a suitable and inexpensive alternative for Bangladeshi buffalo sperm considering post-thaw sperm quality and fertility.