The aim of this study was to test the effect of extenders containing different sugar in their composition on ram sperm motility and pregnancy rate of ewe’s following artificial insemination. Semen were collected from ten North-east Bulgarian fine-fleece breed and tested for quality. Semen was diluted with different extenders, with di- and trisaccharides. A series of experiments were repeated in triplicate. Total motility was determined by using Sperm Analysis (SCA, Microptic, Spain). A total of 200 North-east Bulgarian fine-fleece breed mature ewes were used for cervical insemination with a sperm dose at the concentration of 100 × 106 spermatozoa. Pregnancies were diagnosed 60 days after AI by - a real-time ultrasonic scan device (Alloka SSD 500). In conclusion, our experiments demonstrated that higher sperm motility after storage at 4°C for 24 hours and 48 hours has a ram spermatozoa diluted with extender 1, with combination of disaccharides (sucrose and lactose) and trisaccharides (rafinosa). This semen extender (number 1) can be used for successful insemination of ewes and to enhance pregnancy rate after artificial insemination.

In this study we determined the effect of reactive oxygen species (ROS) generation during incubation in media at 39 degrees C on ram spermatozoa and the protection by exogenously added antioxidant enzyme, superoxide dismutase (SOD). A novel Cu/Zn-SOD, isolated from the fungal strain Humicola lutea 103 (HLSOD), was used. Our results point out that the levels of both, superoxide anion radicals (*O2-) and H2O2, increase approximately 8-10- and 2-3-fold, respectively, during incubation of spermatozoa. Enhanced ROS generation coincided with reduction of motility, independently of the type of diluted medium. Addition of HLSOD (30, 60 and 120 U ml(-1) sperm) improved sperm functions, maintaining almost initial percentages of motile spermatozoa and increasing the values of mean cytochemical coefficient. At the same time, a significant diminution of *O2- and H2O2 content in the presence of antioxidant enzyme was established. The results suggest that HLSOD is an effective *O2- scavenger in semen that leads to protection of sperm functions.

Selenium is a trace element, which stimulates antioxidant defenses and improves reproductive functions in human and animals, under the form of selenoproteins. The objective of the study was to evaluate the effect of selenium, supplemeted as inorganic or organic form in the diet of stud rams, on some of their semen parameters. The experiment was performed with 15 clinically healthy rams from North East Bulgarian merino breed. The animals were divided in three groups (5 per group). The rams from first experimental group (G1) received a diet with supplementation of 4,0mg sodium selenite (Na 2 SeO 3) per animal per day, while the animals of the second experimental group (G2) obtained diet with 1.83g L-selenomethionine (Sel-Plex, Alltech, USA) per animal per day. Eventually, each animal from the G1 and G2 received 1.83g selenium per day. The control group (GC) received a diet without supplementation of selenium. The principal composition of the diet in each group was the same. The ejaculates were obtained via artificial vagina. The evaluated parameters were volume and pH of the ejaculates and motility, concentration and in vitro survivability of the spermatozoa at 39˚С for 360 min. It was found that the supplementation of ram studs diet either with inorganic and organic selenium led to increase in the volume of the Rossen Stefanov et al. 70 ejaculates, motility and survivability of the spermatozoa. The pH of the freshly obtained semen was not affected by selenium treatment.

No abstract

Transition metal ions, mainly iron, are involved in the generation of highly reactive hydroxyl radicals, which are the most powerful inducers of oxidative damage to all biomolecules. The lipids in sperm membranes are highly susceptible to oxidation. Sperm lipid peroxidation (LPO) leads to decrease of motility and reduction of likelihood for sperm-oocyte fusion. The excess radical production may affect also the spermatozoa morphology. The aim of the present study was to investigate the effect of Desferal on the LPO, motility, and morphology of boar sperm subjected to oxidative stress. After collection, the ejaculates were equally separated and diluted in a commercial semen extender (experiment 1) or in physiological saline (experiment 2). The ejaculates of the 2 experiments were divided into aliquots, which were incubated with one of the following agents: FeSO4 (0.1mM), H2 O2 (0.5mM), or FeSO4  + H2 O2 (Fenton system), in the presence or absence of Desferal. The application of Desferal in the incubation medium had a protective effect against FeSO4  + H2 O2 -induced sperm damage, namely, decrease of LPO; decrease the quantity of immotile spermatozoa and decrease the number of morphological abnormalities, regardless of the used medium. In experiment 2, the presence of FeSO4 in the incubation medium induced LPO in the same range as the combination FeSO4  + H2 O2 , in which the effect was reduced by Desferal. Thus, the supplement of Desferal to media used for sperm storage and processing could be a useful tool for diminishing oxidative injury and improving the quality of the semen.

No abstract

The addition of prostaglandin F2α (PGF2α) to boar semen prior to insemination improves the conception and farrowing rates in sows. It is accepted that this is due to increased myometrial contractility, which improves the spermatozoa movement. However, there are limited data about the effect of the exogenous PGF2α analogs on sperm motility parameters and morphology. The aim of the current study was to define if there are changes in motility, morphology and kinematic parameters of spermatozoa on 1 st and 24 th hour after addition of PGF2α analogue to extended boar semen. A total of 18 ejaculates, obtained from clinically healthy boars were diluted 1:3 in semen extender, and each of them was separate into four aliquots, 50 ml each. PGF2α was added to 3 of them in concentrations of 6, 12 and 25 µg/ml, and the fourth served as untreated control. The motility, kinematic parameters and morphology of spermatozoa were evaluated on 1 st and 24 th hours after addition of PGF2α. There was no significant difference in sperm morphology, total and progressive motility between the untreated and treated groups. There was however a significant decrease in the rapid velocity and some of the kinematic parameters (VCL, VSL and VAP) in the group treated with 25 µg/ml compared to the control at the 1 st hour after PGF2α treatment, which (except for the rapid velocity) persisted to the 24 th hour. The results indicate that addition of Oestrophan (Bioveta,CZ) to the extended boar semen did not improve the sperm motility, morphology and kinematic parameters of the spermatozoa.

Original Scientific ArticleSelenium is an essential micro-element in animal diet due to its high antioxidative properties. As a part of selenocystein it is an important constituent of the glutathione peroxidase (GPx) enzyme, which has a big importance for cell protection from oxidative damage. The aim of the present work was the investigation of the selenopyran effect on the antioxidative state of the pig ovary. The experiment was conducted with 18 gilts of Danube white breed randomly divided into two groups between 120 -228 days of age. The animals received equal basal diets without selenium additives. The experimental gilts were injected once per month intramuscularly with oil solution of preparation selenopyran (9-phenylsymmetrical octahydroselenoxanthene) ensured 0.1 mgSe/kg live weight. After slaughtering, the ovaries were used for histological analysis and estimation of the selenium content in ovarian tissue by the atomic absorption spectroscopy method. The GPx activity in ovary homogenates using the colorimetric assay kit (BioVision) was measured. The expression of γ-glutamyl transpeptidase (GGT) in ovaries by immunochistochemical method was estimated. The selenopyran treatment leads to significant (P<0.05) increase of the selenium level in blood and non-significant (P>0.05) in ovarian tissue. Enhancement of GPx activity in the ovaries of experimental group was observed (142.61±6.6 versus 122.28±3.4U/gP, P<0.05). The GGT expression in the ovarian cortex cells, follicular fl uid and in the erythrocytes of ovarian blood vessels in treated gilts was an evidence of active transport of glutathione from blood to the ovary tissue. The selenopyran treatment promotes the increase of the GPx dependent antioxidative defense in ovary of growing gilts.