Effect of season on the dynamics of cat sperm DNA fragmentation.

BACKGROUND: Feline species undergo reproductive seasonality; thus, sperm characteristics, such as DNA integrity, can be affected by the photoperiod. This study was conducted to determine the effect of seasonal changes on sperm quality and on the dynamics of sperm DNA fragmentation. Epididymal spermatozoa were collected from 36 tomcats subjected to bilateral orchiectomy during breeding (BS) and non-breeding (NBS) seasons. Sperm samples were obtained by cutting the cauda epididymis and assessed for sperm motility, concentration, acrosome integrity, plasma membrane integrity and sperm morphology. Sperm DNA fragmentation was evaluated by the sperm chromatin dispersion test after 0, 6, and 24 h of incubation at 37 °C. RESULTS: The total sperm motility and plasma membrane integrity values were greater during the BS, while the percentages of abnormal sperm and head defects were lesser (p < 0.05). No significant differences in DNA fragmentation were found between seasons after sperm collection. DNA damage was greater after 24 h of incubation at 37 °C in both seasons, although the percentage of spermatozoa with fragmented DNA was significantly lesser in the BS than in the NBS at 24 h (p < 0.05). CONCLUSIONS: The study suggests seasonal changes in some of the quality parameters of cat sperm. DNA fragmentation dynamics were affected by the time of incubation and reproductive season; therefore, this technique might be used as an additional tool to test the potential fertility of semen samples used in feline-assisted reproduction.

Specific phosphodiesterase type-10 inhibitor, papaverine, added after the cooling period improves canine sperm quality.

The use of chilled semen has gained increasing interest in canine reproductive services. The addition of phosphodiesterase (PDE) inhibitors that increase the intracellular cyclic adenosine monophosphate levels may improve sperm motility. The purpose of this study was to examine the quality of sperm under the effect of the specific PDE-10 inhibitor (papaverine) added after storage for 1, 2, and 3 days at 5 °C. The ejaculates were obtained from 5 healthy Beagle dogs by digital manipulation. After collection, ejaculates were pooled, extended and cooled at 5 °C during 3 days. Sperm parameters were tested 30 min after the addition of different papaverine (PA) concentrations: 0, 5, 10 and 20 µM. Sperm motility (CASA), viability (PI/FITC-PNA) and capacitation status (chlortetracycline assay) were evaluated. The results showed that the addition of PA has no effect on sperm samples at day 0. However, concentrations of 5 and 10 µM increased (p < .05) sperm motility kinetics and viability significantly compared to the control at day 1, day 2 and day 3 of cooling. The addition of 20 µM PA decreased (p < .05) sperm quality parameters significantly and increased the percentage of capacitated/acrosome-reacted spermatozoa. In conclusion, the addition of 5 and 10 µM PA concentrations after cooled storage improved canine sperm quality.

Morphological Characteristics of the Sperm of the Peregrine Falcon (Falco peregrinus) during the Reproductive Season.

The morphological characteristics of different sperm cells (normal, abnormal, and immature) in the peregrine falcon during the reproductive season were analysed. We also classified the main sperm defects found in semen. Semen samples were collected from mature peregrine falcons via cloacal massage and stained with Diff-Quik stain. The percentages of normal, abnormal, and immature sperm cells were determined by bright-field optical microscopy. The number of normal spermatozoa were greater at the initial stage and subsequently decreased during the middle and later stages of the reproductive season (p < 0.01). In contrast, the percentage of abnormal spermatozoa increased significantly in the middle and end stages of the reproductive season (p < 0.05), whereas the proportion of immature spermatozoa remained stable during the study. Head defects represented the greatest proportion of morphological abnormalities, followed by the defects in the tail and midpiece regions. A small percentage of multiple defects and cytoplasmic droplets were also observed in the falcon spermatozoa. The findings of this study might be important for the development of future conservation protocols for falcon sperm.

Correlation of Prostatic Artery Blood Flow Assessed by Doppler Ultrasonography with Semen Characteristics in Beagle Dogs.

Pulsed-wave Doppler ultrasonography (PwD) is a method used to rapidly and noninvasively assess blood flow dynamics of the canine prostate. Modifications in gland vascularization can affect seminal plasma production and consequently sperm quality. The aim of this study was to determine the normal blood flow parameters of the prostate artery in beagle dogs and to analyze the correlations between vascular flow and semen quality characteristics. PwD was performed on five beagle dogs (5-6 years) measuring vascular features in four different locations of the prostatic artery (cranial, subcapsular, parenchymal and caudal); the measured features were peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI). Ejaculates were obtained using digital manipulation and semen quality was evaluated by determining macroscopic (total volume, sperm-rich fraction volume, color and pH) and microscopic (sperm motility, morphology, viability and acrosome integrity) characteristics. The values of PSV, PI and RI in cranial and caudal prostatic arteries were significantly higher than in subcapsular and parenchymal arteries (p < 0.05). Moreover, a positive correlation of PSV value in the cranial region of the prostatic artery with total ejaculate volume (p < 0.01, r = 0.612) and sperm concentration (p < 0.01, r = 0.587) was determined. PI index was negatively correlated with sperm concentration (p < 0.01, r = -0.709). In conclusion, the results suggest that the prostatic artery blood flow parameters can affect macroscopic semen quality characteristics in healthy dogs.

Colloid centrifugation reduces bacterial load in chilled dog semen.

Conventional semen extenders contain antibiotics to prevent bacterial growth. Finding alternatives would be beneficial to minimize the development of bacterial resistance mechanisms. The aim of this study was to determine the effect of Single Layer Centrifugation (SLC) with Canicoll of dog semen on microbial load and sperm quality during cooled storage. Twenty-four ejaculates were obtained from healthy dogs by digital manipulation. Samples were diluted in Tris-citrate-fructose extender without antibiotics and divided into two treatment groups: SLC-selected samples and unselected samples. Sperm motility (CASA), viability and acrosome integrity (PI/FITC-PNA) as well as bacterial load of each microorganism species (colony-forming units/mL) were assessed at 0 and 48 h of storage at 4 °C. Results indicate SLC-selected dog spermatozoa have greater percentages of motility, viability and acrosome integrity (P < 0.05). Bacterial growth in SLC sperm samples was less (P < 0.05) than unselected samples. Removal of individual bacterial species varied from 91 % to 98 % for Escherichia coli (91.62 %), Streptococcus spp. (98.18 %), Staphylococcus spp.(95.33 %) and Pseudomonas spp. (92.50 %). In conclusion, the use of SLC with Canicoll has the potential to decrease bacterial load in chilled dog semen.

Sperm Tail Defects and Abnormal Testicular Blood Flow in a Beagle Dog: A Case Report.

A 5-year-old male Beagle dog produced ejaculates with a high percentage of spermatozoa with abnormal morphology, especially sperm tail defects. Although libido and semen volume were normal, ejaculates showed asthenospermia, oligozoospermia, and teratozoospermia. The spermatozoa exhibited morphologic defects affecting the flagellum, mainly coiled tails with or without macrocephalia (33.5 ± 2.1%), bent tails (18.3 ± 3.4%), and proximal cytoplasmic droplets (6.7 ± 2.8%). The peripheral plasma testosterone level was 2.76 ± 0.21 ng/mL. The resistive index and the pulsatility index from marginal and intratesticular vessels measured by Doppler ultrasound showed higher values in the right testicle than in the left testicle. Histologic evaluation revealed focal reduction in the number of germ cells and sperm in the seminiferous tubules in the right testicle. This is the first report that describes simultaneously the presence of sperm tail defects in the ejaculate and changes in the blood flow of testicular vessels in the dog.

Alternatives in Donkey semen cryopreservation: Mare vs. Jenny Colostrum.

The aim of this study was to test and compare two new components in extenders for freezing donkey semen: mare colostrum and jenny colostrum. Colostrum was obtained from four mares and four jennies right after the foal's birth. Ejaculates were collected from five fertile donkeys. Sperm samples were pooled, diluted and cryopreserved in three different experimental extender groups: lactose supplemented with egg yolk extender (20%) as the control group, lactose supplemented with jenny colostrum extender (20%), and lactose supplemented with mare colostrum extender (20%). After thawing, we evaluated the sperm motility by means of computer-assisted analysis, viability by SYBR-14 and propidium iodide (PI), membrane functional by HOS test and acrosome integrity by isothiocyanate conjugated with peanut agglutinin (FITC-PNA) and PI. The results demonstrated that lactose-jenny colostrum extender displayed significantly higher values (p < .05) in nearly all parameters evaluated - Total Motility, Viability, HOS test, VCL, VSL, VAP, LIN, STR and WOB -, compared with mare colostrum and egg yolk extenders after thawing. In conclusion, the extender containing jenny colostrum used for donkey semen cryopreservation improved the donkey sperm quality after the freezing-thawing process.

Progesterone improves porcine in vitro fertilisation system.

In an effort to improve the quality of in vitro produced porcine embryos, the effect of progestagens - progesterone analogues - on the in vitro developmental competence of porcine oocytes was studied. A total of 1421 in vitro matured oocytes, from 4 replicates, were inseminated with frozen-thawed spermatozoa. Progestagens were added to late maturation and embryo cultures (10 IU/ml). Fertilisation success (pre-maturation, penetration, monospermy and efficiency) and nuclear maturation were evaluated. There were no differences among prematuration rates between groups (P = 0.221). Penetration rates were higher (P < 0.001) in the presence of progestagens (75.0%) as compared to the control (51.7%). However, no differences were observed in monospermy percentages (P = 0.246). The results indicated that supplementation with progestagens increased the efficiency of the in vitro fertilisation system (P < 0.001). An additional beneficial effect was observed in nuclear maturation with progestagens (P = 0.035). In summary, progestagen supplementation is an important factor to improve the in vitro fertilisation procedure.

Plasmaféresis en el tratamiento del síndrome hemolítico-urémico típico / Plasmapheresis in the treatment of typical haemolytic-uraemic syndrome

No disponible

Effect of the in vitro maturation medium on equine oocytes: comparison of follicular fluid and oestrous mare serum.

The present study evaluated the effect of supplementing the medium used to mature equine oocytes in vitro with oestrous mare serum (EMS) or horse follicular fluid (HFF). To this end, 144 ovaries were obtained from mares aged 16-21 months and transported to the laboratory in Dulbecco's phosphate buffered saline (D-PBS) at 30 degrees C. Oocytes were harvested from the ovaries by slicing, and then selected for in vitro maturation (IVM) according to the number of cumulus cell layers and the characteristics of the cytoplasm. The selected oocytes were washed three times in TCM199 medium plus HEPES (TCM-199H) or in the same medium plus glutamine (TCM-199G), then matured in vitro in six study groups established according to the in vitro maturation (IVM) treatment to see possible interactions between HEPES and glutamine on other supplements: Ten percent EMS was added to two of these media (TCM-199H+EMS and TCM-199G+EMS) and 10% HFF was added to the media in two other groups (TCM-199H+HFF and TCM-199G+HFF). IVM was performed at 38.5 degrees C for 40 h in a controlled atmosphere (5% CO2, 95% relative humidity). The findings indicate that the presence of EMS or HFF in the TCM-199H medium gives rise to the best results in terms of the proportions of oocytes reaching maturity (37.7% and 36.8%, respectively). The values obtained with EMS and HFF were statistically similar to each other but differed from the other treatments. The media containing glutamine led to the highest proportions of degenerated oocytes.