The cryoprotective potential of propolis supplemented in frozen-thawed bull semen; biochemical and physiological findings.

In this study, the cryoprotective effect of different doses of propolis (P) on bull semen, which has solid pharmacological properties thanks to its rich phenolic components, was investigated biochemically and physiologically. Semen samples were collected from Simmental breed bulls via the artificial vagina and pooled. After dividing into five groups, control (C: no additive) and four different P (200, 100, 50, and 25 µg/mL) groups, the final concentration was diluted to 16×106 per straw. Semen samples were equilibrated at 4°C for approximately 4 hours, then placed in French straws and frozen. After thawing, sperm motility and kinetic parameters, DNA integrity by single-cell gel electrophoresis, sperm abnormalities by liquid fixation, and lipid peroxidation levels by the colorimetric method was analyzed by Computer-Assisted Semen Analyzer. P added to the diluent showed no effect on motility and kinetic parameters at P25 and P50 (p>0.05), while P100 and P200 had a negative effect (p⟨0.001). The addition of P (25 and 50) showed a treatment effect on tail abnormality compared to C (p⟨0.05). Especially P50 had a positive effect on tail length, tail DNA, and tail movement, while P100 and P200 caused DNA damage (p⟨0.001). MDA levels increased in all P dose groups compared to C (p⟨0.001). This study has clearly demonstrated that P25 and P50 supplements could be used therapeutically to treat sperm tail abnormalities and prevent DNA damage in post-thawed bull sperm.

The effects of different PMSG doses on estrus behavior and pregnancy rate in Angora goats.

Artificial insemination protocols depend on efficient behavioral estrus detection and insemination time in Angora goat. Therefore, we aim to determine the accuracy of an estrus scoring system in Angora goats with different PMSG doses during the breeding season. Does (n: 260) were randomly divided into three groups: group-1 (n: 93), group-2 (n: 85) and group-3 (n: 82). All animals received an intravaginal sponge on day 0 for 11 days, and on the day of sponge insertion 150 µg prostaglandin F2Α was administered. Pregnant mare's serum gonadotropin was injected 300, 400 and 500 IU intramuscularly 24 h before sponge removal to groups 1, 2 and 3, respectively. Estrus signs were detected with a teaser buck, 24 h after sponge removal according to a visual scoring system. Artificial insemination was performed with 0.25 ml fresh diluted semen at 43 to 45 h after sponge removal. Differences were observed within PMSG groups in terms of standing, tail wagging, courtship behavior, vaginal discharge and vaginal hyperemia (P<0.001). Nevertheless, the most accurate indicators of estrus that result in pregnancy were tail wagging and courtship behavior followed by standing estrus (P<0.05). According to the results obtained, 300 IU PMSG dose is sufficient, both to inseminate at a fixed time (43 to 45 h after sponge removal) and to record the estrus behavior by teaser male 24 h after sponge removal. Higher PMSG doses (400 to 500 IU) altered the timing of ovulation; specifically, 500 IU dose shortened the duration of estrus behaviors. In conclusion, even though the different doses of PMSG displayed similar effects on estrus synchronization and pregnancy rates, we concluded that tail wagging, courtship behavior and standing heat are the most reliable estrus signs for artificial insemination in Angora goat.

Supplementation of Rosmarinic Acid Has Reduced Oxidative Stress on Bull Spermatozoa Following the Freeze Thawing Process.

BACKGROUND: Cryopreservation has a side effect on the motility, chromatin integrity and viability of sperm cells. OBJECTIVE: The present study investigated the effects of supplementation with rosmarinic acid (RA) Tris extender on sperm quality parameters, plasma and acrosome membrane damage, antioxidant enzyme activity and chromatin integrity following the freeze thawing process on bull spermatozoa. MATERIALS AND METHODS: Ejaculates were split into five aliquots and diluted to a final concentration of 15x106 spermatozoa per ml with the Tris extender containing RA (25, 50, 100 and 200 microgram per ml) and (control) and then frozen at a controlled rate. RESULT: Treatments did not give better results on the percentages of sperm progressive, total motility and sperm motion characters (P >0.05); however, RA25 and RA50 exhibited favourable chromatin integrity. In conclusion, RA25 and RA50 increased total antioxidant activity. As a consequence, the amount of MDA and chromatin damage were reduced in sperm cells.

Supplementation of quercetin for advanced DNA integrity in bull semen cryopreservation.

The aim of this study was to identify the effects of adding quercetin (Q) to Tris extender in order to identify levels of oxidative stress in bull sperm after freeze thawing. Ejaculates were collected via artificial vagina from Holstein bulls. Semen was divided into five tools and diluted to a final concentration of 15 × 106 spermatozoa/ml with the Tris extender containing Q (25, 50, 100 and 200 µg/ml) and no additive (control; C). All examples were equilibrated at 4°C during 4 hr then were loaded into 0.25-ml straws and frozen using a controlled rate. Sperm motility and motility characteristics were determined using the computer-assisted semen analyser. Sperm membrane integrity was assessed using the hypoosmotic swelling test. Sperm chromatin integrity was investigated using the single cell gel electrophoresis. Total antioxidant capacities were performed colorimetrically. Q supplementation used as an antioxidant did not produce better results in the proportion of sperm progressive and total motility, plasma membrane integrity and sperm abnormalities. Q supplementation exhibited the favourable tail length, tail DNA and tail moment. In conclusion, when whole parameters are considered, Q25 can be added to the Tris extender due to its positive effect on sperm DNA integrity and no adverse effect on the progressive and total motilities of sperm.

Lycopene and resveratrol improve post-thaw bull sperm parameters: sperm motility, mitochondrial activity and DNA integrity.

We focussed on evaluating the protective effect of lycopene and resveratrol on post-thaw bull sperm and oxidative stress parameters. Nine ejaculates for each bull were used in the study. Each ejaculate, splitted into three equal aliquots and diluted at 37 °C with base extenders containing lycopene (1 × 10(-3)  g ml(-1) ) and resveratrol (1 mm), and no antioxidant (control), was cooled to 5 °C and then frozen. Frozen straws were thawed in a water bath for evaluation. The supplementation of the semen extender with lycopene and resveratrol increased the percentages of post-thawed computer-assisted sperm analysis (CASA) motility (55.8 ± 3.8 and 61.9 ± 4.0%) and progressive motility (38 ± 2.4 and 37 ± 8.8), compared with the controls (50.7 ± 2.65 and 33.3 ± 3.74%, respectively, P < 0.05). Resveratrol provided a higher ALH (4.3 ± 0.1), in comparison with the control (3.9 ± 0.3, P < 0.05). The supplementation of the semen extender with lycopene and resveratrol produced a higher mitochondrial activity (24.6 ± 2.9 and 30.1 ± 6.5% respectively), compared with that of the control (11.8 ± 9.5%, P < 0.05). It was determined that both antioxidants resulted in a lower percentage of sperm with damaged DNA than that of the control (P < 0.05). Sperm motion characteristics except for ALH, acrosome integrity, sperm viability and oxidative stress parameters were not affected by the adding of lycopene and resveratrol.