Effect of fumigation height and time on cryopreservation of ram semen

The cooling rate is a crucial factor in the process of freezing semen, influencing the overall freezing effectiveness. The height and time of fumigation can significantly impact the rate of cooling. Appropriate cooling rates can help minimize the formation of ice crystals in spermatozoa and reduce potential damage to them. Therefore, the aim of this study was to evaluate the effect of different fumigation heights and time for the cryopreservation of Hu ram semen. Experiments I-IV assessed the effect of semen cryopreservation by testing the post-thawed spermatozoa total motility (TM), progressive motility (PM) and kinetic parameters fumigated at distances of 2, 4, 6 and 8 cm for durations of 5, 10, 15 and 20 min, respectively. Based on the results of experiments I to IV, experiment V evaluated the effect of semen cryopreservation by testing the post-thawed spermatozoa TM, PM, kinetic parameters, plasma membrane integrity, acrosome integrity and reactive oxygen species (ROS) level fumigated at distances of 2, 4, 6 and 8 cm for duration of 20 min. The results indicated that fumigation at 2 cm for 20 min significantly (P < 0.05) improved spermatozoa TM, PM, mean angular displacement (MAD), plasma membrane integrity and acrosome integrity compared to other groups. Additionally, it significantly (P < 0.05) reduced spermatozoa ROS level compared to the 6 and 8 cm groups. In conclusion, fumigation for 20 min at a distance of 2 cm from the liquid nitrogen surface is the most suitable cooling method for the cryopreservation of Hu ram semen.

Punicalagin Protects Ram Sperm from Oxidative Stress by Enhancing Antioxidant Capacity and Mitochondrial Potential during Liquid Storage at 4 °C

The aim of this study was to investigate the effect of punicalagin, an antioxidant, on ram sperm quality. Semen samples were collected and pooled from five rams, then diluted using a Tris-based diluent containing various concentrations (0, 5, 15, 30 and 45 μM) of punicalagin. Sperm motility, plasma membrane integrity, acrosome integrity, total antioxidant capacity (TAC), reactive oxygen species (ROS), malondialdehyde (MDA), mitochondrial membrane potential (MMP), superoxide dismutase (SOD) and catalase (CAT) were measured and analyzed during liquid storage at 4 °C. The results showed that the Tris-based solution containing punicalagin improved sperm motility, plasma membrane integrity, acrosome integrity, TAC, SOD, CAT and MMP, and decreased ROS content and MDA content. At the same time, the semen sample diluted with the Tris-based solution supplemented with 30 μM punicalagin achieved the best effect. The sperm total motility, progressive motility, plasma membrane integrity, acrosome integrity, TAC, SOD, CAT and MMP of the group supplemented with 30 μM punicalagin were significantly (p < 0.05) higher than those of the other groups on the 5th day during the liquid storage at 4 °C. Meanwhile, the ROS content and MDA content were significantly (p < 0.05) lower than those in the other groups. In conclusion, the optimal concentration of punicalagin in the Hu ram semen diluent was determined to be 30 μM. The results indicated that a diluent supplemented with punicalagin could enhance the quality of ram sperm preserved at 4 °C by increasing antioxidant capacity, mitochondrial potential and reducing oxidative stress.

Astaxanthin Improved the Quality of Hu Ram Semen by Increasing the Antioxidant Capacity and Mitochondrial Potential and Mitigating Free Radicals-Induced Oxidative Damage

The objective of this research was to investigate the effect of astaxanthin supplementations of semen extender on the quality of Hu ram semen after up to five days of preservation at 4 °C. Semen samples were collected from five healthy Hu rams using an artificial vagina during breeding season (April to August 2023) and diluted with a basic extender supplemented with control (0), 1 µM, 2 µM, 3.5 µM, or 4.5 µM of AXT. Overall, 170 semen ejaculate samples (34 repetitions) from five healthy Hu rams were used in our research study. The results revealed that the addition of AXT (3.5 µM) significantly (p ≤ 0.05) increased the sperm kinematic indexes (T.M%, P.M%, MAD%, STR%, and LIN %), sperm viability, plasma membrane integrity, acrosome integrity, total antioxidant content (T-AOC), and mitochondrial membrane potential (MMP) of the Hu rams spermatozoa after up to five days of preservation at 4 °C. Contrary to that, the addition of the best concentration of AXT (3.5 µM) to the semen extender significantly (p ≤ 0.05) reduced the reactive oxygen species (ROS) and malondialdehyde (MDA) concentration of Hu ram semen. In conclusion, the results of the current study indicate that the addition of a semen extender with AXT improves the quality of Hu ram spermatozoa by increasing the total antioxidant capacity (T-AOC) and mitochondrial membrane potential (MMP). On the other hand, reducing free radicals induced oxidative (ROS) and per oxidative (MDA) damage to Hu ram semen.

Alpha-lipoic acid improves the quality of ram spermatozoa stored at 4°C by reducing oxidative stress and increasing mitochondrial potential

Introduction

Ram spermatozoa inevitably produce a large number of reactive oxygen species (ROS) during liquid storage, leading to oxidative stress and a decline of spermatozoa quality. Therefore, it is particularly important to add exogenous antioxidants during the process of semen liquid preservation. The purpose of this study is to investigate whether adding alpha-lipoic acid (ALA) to ram semen can reduce oxidative stress and enhance spermatozoa quality during the liquid storage at 4°C.

Methods

Different concentrations of ALA (0, 0.025, 0.05, 0.1, 0.5, 1 mM) were added to semen and stored at 4°C. During storage at 4°C, spermatozoa motility, kinetic parameters, membrane integrity, acrosome integrity, energy metabolism parameters (mitochondrial membrane potential (ΔΨM) and adenosine triphosphate (ATP)) and oxidative stress parameters [ROS, malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD)] were assessed.

Results and discussion

The results indicated that 0.1 mM ALA significantly (p<0.05) improved spermatozoa total motility (TM) and progressive motility (PM), plasma membrane integrity, acrosome integrity, ΔΨM, ATP, TAC, and SOD, while significantly (p<0.05) reducing spermatozoa ROS and MDA content compared to the control group. In conclusion, ALA can reduce damage caused by oxidative stress in spermatozoa and effectively improve the quality of semen preserved at 4°C. And the optimal concentration is 0.1 mM.

Ovarian Dynamics and Changes in Estradiol-17β and Progesterone Relationship with Standing Estrus, Preovulatory Follicles, and Ovulation Using Single Prostaglandin F2α Injection in Barbari Goats

The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF2α injection, administered indiscriminately during the breeding season of Barbari goats. Ovarian dynamics were observed at every 12 h interval by using B mode ultrasonography, blood samples for hormonal analysis such as estradiol 17β and progesterone were collected at every 12 h interval, and bucks with aprons were used to identify standing estrus at every 6 h interval. Relative to PGF2α, the start of standing estrus and ovulation differ (p < 0.05) between early- (n = 7), intermediate- (n = 6), and late-responding (n = 6) goats. The highest plasma level of estradiol 17β was detected 12 h prior to ovulation. The average diameter of the ovulatory follicle and length of standing estrus were comparable (p > 0.05) between the goats. The corpus luteum degenerated more quickly (p < 0.05) in early- than intermediate- and late-responding goats. Dominant follicle diameter and estradiol 17β concentration also differ (p < 0.05) among groups. Although the plasma level of progesterone did not vary (p = 0.065), the variation in progesterone concentration with time differed (p < 0.05) amongst the goats. As a result, this research indirectly reveals that the beginning of standing estrus, end of estrus, and ovulation after PGF2α might fluctuate in Barbari goats because of follicular and hormonal dynamics during the luteal phase.

Effects of Different Diluents on Semen Quality of Hu Ram Stored at 4 °C

This study aimed to investigate the effects of various diluents on the quality of Hu ram sperm stored at 4 °C. Semen samples were collected from three Hu rams and diluted with diluents A (Sodium citrate-Glucose-Egg yolk), B (Sodium citrate-Glucose), C (Fructose-Skimmed milk powder-Soy lecithin), and D (Tris-Fructose-Citric acid-Egg yolk). Total motility (TM), straight-line velocity (VSL), average path velocity (VAP), curvilinear velocity (VCL), average motion degree (MAD), acrosome integrity, membrane integrity, and reactive oxygen species (ROS) were evaluated. The results showed that diluent D had better preservation in terms of the sperm TM, VSL, VCL, VAP, MAD, and membrane and acrosome integrity. On the third day of the storage, the sperm PM of diluent D was higher than that of other diluents (p < 0.05). The ROS level of diluent D was lower than that of other diluents on the fifth day (p < 0.05). On the seventh day of the storage, the sperm TM in diluent D reached 50%, which was the highest in all diluent groups. On the seventh day of the storage, the integrity of the sperm membrane and the integrity of the acrosome of the sperm in diluent D were the highest in all diluent groups (p < 0.05). In conclusion, these results indicated that diluent D improved the semen quality during storage at 4 °C. In this study, diluent D was the best diluent formula for Hu ram semen stored at 4 °C.

118 A retrospective analysis of follicular dynamics, LH, estradiol-17β, and progesterone in prostaglandin F2α-induced estrus of Beetal goats

The objective of the study was to reveal the factors associated with variable interval to ovulation following a single dose of prostaglandin F2α (PGF2) in Beetal goats. In experiment 1, the extent of ovulation time was demonstrated after synchronizing Beetal goats (n=38) by using a single injection of PGF2 based on corpus luteum detection by B-mode transrectal ultrasonography. Ovulations were detected every 6h from PGF2 until ovulation. To explore the changes in follicular dynamics, endocrine profiles and behavioural events due to the variation in the interval to ovulation, another set of goats (n=13; experiment 2) were synchronized by a single dose of PGF2 given at random days of the luteal phase. Follicular dynamics were monitored every 12h from PGF2 until ovulation and oestrus was detected by apronized bucks every 6h from PGF2 treatment. Blood sampling (3mL) for oestradiol-17β and progesterone was done every 12h from PGF2 until ovulation and every 2h for LH assay by radioimmunoassay. Data were analysed by Student’s t-test, general linear models, and Pearson coefficient correlation (SPSS, version 20.0, SPSS Inc., Chicago, IL, USA). Results revealed that ovulation time varied from 60 to 96h after PGF2, and 57% of ovulations occurred by 72h after PGF2 (experiment 1). Based on this observation, goats (n=13) in second experiment were retrospectively divided into early and late ovulators (i.e. 72 and 84h following PGF2, respectively). Onset of oestrus, peak oestradiol-17β concentration, and LH surge after PGF2 were first observed in early than late ovulators (P&lt;0.05). The goats having greater follicle diameter and smaller corpus luteum diameter at the time of PGF2 ovulated earlier than late ovulators (5.4±0.2v. 4.3±0.2mm and 10±0.6v. 11.8±0.3mm, respectively; P&lt;0.05). Likewise, plasma progesterone concentration tended to be lower (P=0.087) in early than late ovulators. However, interval from onset of oestrus to peak LH and ovulation, duration of standing oestrus, interval from LH peak to ovulation, diameter and growth rate of preovulatory follicles, and number of ovulations were similar (P&gt;0.05) between early and late ovulators. In conclusion, the size of dominant follicle and corpus luteum at the time of PGF2 determines the interval to ovulation following a single dose of PGF2 during the luteal phase.