The relationship between sperm concentration and fertilization in vitro of rabbit ova

Different concentrations of in utero incubated rabbit sperm (1.5 × 10⁴-120 × 10⁴ /ml) were tested to determine whether there is a relationship between sperm concentration and level of fertilization achieved “in vitro” of rabbit ova. While low concentrations (1.5 × 10⁴-4.5 × 10⁴ /ml) resulted in relatively low fertilization (23–36%), those in the range of 13 × 10⁴?120 × 10⁴ /ml gave fertilization rates of 65–83%. Consistently high results were obtained with sperm counts above 40 × 10⁴ /ml. This is in agreement with the concentration of spermatozoa found in vivo in the Fallopian tubes around the time of fertilization (50 × 10⁴ /ml).     

Changeability of sperm chromatin structure during liquid storage of ovine semen in milk-egg yolk- and soybean lecithin-based extenders and their relationships to field-fertility

The aim of this experiment was to study the effect of semen extender on sperm chromatin structure and to correlate chromatin integrity with field-fertility of preserved ram semen. Ejaculates of at least 2 × 10⁹ sperm/ml and 70 % progressive motility were collected using an artificial vagina from Chios rams (n = 11, 4–6 years old), split-diluted to 1 × 10⁹ sperm/ml with milk-egg yolk- and soybean lecithin (Ovixcell^®)-based extenders, packaged in 0.5-ml straws and examined after 6, 24 and 48 h of storage at 5 ± 1 °C. Evaluation endpoints were computer-assisted sperm motion analysis, fluorescence-based analysis of chromatin structure by chromomycin A₃ and acridine orange assays, and 65-day pregnancy rate (PR) of 34- to 36-h preserved semen after intra-cervical insemination of ewes (n = 154) in progestagen-synchronized estrus. Neither extender nor storage time had any influence on incidence of decondensed chromatin. Unlike Ovixcell^® extender, deterioration of sperm motility (P < 0.01) and chromatin stability (P < 0.005) was detected after 48 h of storage in milk-egg yolk extender. Sperm motility accounted for 14.4–18.5 % of variations in chromatin integrity (P < 0.001). No significant difference was found in PR of Ovixcell^®- and milk-egg yolk-stored semen. Nevertheless, PR differed between rams (14.3–71.4 %; P < 0.025). Chromatin integrity explained 10.2–56.3 % of variations in PR (P < 0.05–0.01). A pronounced decline in PR (19.1 %) was observed when percentages of decondensed and destabilized chromatin have reached thresholds of 10.5–30 % and 4–9 %, respectively. In conclusion, Ovixcell^® is superior to milk-egg yolk extender in preserving chromatin stability and motility. Chromatin defects are negatively associated with sperm fertility.     

First pregnancies in jennies with vitrified donkey semen using a new warming method

Sperm vitrification has been recently developed, but fertility trials have not been performed yet in equine species. In this study, a new warming technique for vitrified donkey semen was developed and the uterine inflammatory response and fertility were compared to conventional freezing. In Experiment 1, sperm was vitrified in straws and warmed in 3 ml of extender or in a water bath at: 37 °C/30 s; 43 °C/10 s; and 60 °C/5 s. Sperm motility, plasma and acrosome membranes and DNA integrity were compared between treatments. In Experiment 2, jennies were inseminated twice (500 × 10⁶ sperm) in the uterine body either with vitrified or frozen semen (2 cycles/jenny). Pregnancy rates and the uterine inflammatory response (polymorphonuclear neutrophil concentration; PMN) were evaluated after artificial insemination (AI). No differences between warming in extender/water bath were found and 43 °C/10 s was better than lower temperatures in terms of total (53.8 ± 13.2%) and progressive sperm motility (41.4 ± 11.4%). No differences in PMN concentration (× 10³ PMN/ml) were found between vitrified (276.8 ± 171.6) or frozen (309.7 ± 250.7) semen after AI. However, PMN decreased faster (P < 0.05) using vitrified semen. Pregnancy rates were greater for vitrified (22%) than frozen semen (10%) but not statistically different. In conclusion, donkey sperm vitrified in straws could be directly warmed in a water bath at 43 °C/10 s, reducing the uterine inflammatory response obtained after AI and promoting positive pregnancy outcomes. These findings confirm the possibility to use vitrified semen as an alternative for AI in jennies.     

Semen evaluation of giant pandas (Ailuropoda melanoleuca) at the Wolong Reserve

Semen from 4 wild-caught giant pandas (Ailuropoda melanoleuca) held at the China Conservation and Research Centre for the Giant Panda was collected (22 samples during 1991–1993) by electroejaculation, and evaluated for use in artificial insemination. Semen characteristics (mean ± SD) recorded were as follows: semen volume–1.5 ± .9 ml (range—0.3–3.5); sperm density 1.5 ± 0.1 × 10⁹/ml (range—0.24–4.2); motility 79 ± 10% (range—60–95); abnormal sperm 14 ± 5% (range—10–27); and pH 7.1 ± 0.2 (range—6.7–7.5). There were significant differences from year to year (P < 0.05) in semen volume collected and in the percentage abnormal sperm in 1993 compared to other years. There were no significant differences among semen produced from the four different pandas. Data collected were similar to reports for other giant pandas, and semen from all 4 giant pandas was considered suitable for use in artificial insemination. © 1994 Wiley-Liss, Inc.     

Efficacy of TEPA as a “sperm label” for competitive fertilization studies in the rabbit

In this paper, the conditions necessary to use TEPA [tris (1-aziridinyl)] effectively as a label for spermatozoa in competitive fertilization are established. The fertilizing ability of rabbit spermatozoa treated with 0 and 0.8 mg TEPA/ml was compared at insemination doses of 1, 5, 20, and 40 × 10⁶ spermatozoa. Fertility was assessed by collecting ova from 64 does 48 to 52 h after insemination. TEPA blocked all but 4% of the ova from developing when 1 × 10⁶ spermatozoa were inseminated, but fertility was reduced. When 5 × 10⁶ spermatozoa were inseminated following treatment with 0, 0.6 or 1.2 mg of TEPA/ml, the fertility was 83, 74 and 50% (P<0.05), and the percentage of ova containing more than four blastomeres was 83, 11 and 5% (P<0.05), respectively. The 0.6% TEPA level was selected for a competitive fertilization trial. Equal numbers of sperm from pure Dutch-color and albino sires were combined so that either both types were untreated, only the ‘albino’ semen was treated, only the ‘Dutch’ semen was treated, or both were treated. Does were inseminated with 5 × 10⁶ sperm and allowed to kindle. The litter sizes were 5.6, 3.1, 2.7, and 0 young, and the proportion of Dutch-color progeny was 63, 97, 0 and 0%, respectively, confirming the effectiveness of TEPA as a “label”. Only one of 60 young born resulted from fertilization by a TEPA-treated spermatozoon, demonstrating that few embryos fully escape the TEPA block. Thus, the TEPA concentration and sperm numbers were established to use TEPA effectively as a label for spermatozoa in competitive fertilization studies.     

Influence of season on characteristics of the ejaculate from bulls in an artificial insemination centre in Nigeria

The influence of season on the ejaculate characteristics of Zebu, Friesian and their crossbred bulls in an A.I. programme in Nigeria was investigated over a 2-year period.Ejaculate volume, sperm concentration, percent morphologically normal spermatozoa and percent live spermatozoa were significantly higher in the rainy season than in the dry season. Total spermatozoa per ejaculate averaged 3.32 × 10⁹ and 10.10 × 10⁹ for the dry and rainy seasons respectively. Corresponding proportions of total morphologically defective spermatozoa per ejaculate were 14.05% and 6.46%. Percent live spermatozoa were 82.34% and 84.61% while the corresponding sperm concentrations were 0.97 × 10⁹ rmand 1.74 × 10⁹ for the dry and rainy seasons respectively. All differences were statistically significant (P < 0.05).Ejaculate quality was better during the rainy season. Consequently semen collected and frozen during the rainy season may produce higher fertility rates in an A.I. programme.     

The effect of optimal and suboptimal concentrations of sperm on the fertility of fresh and frozen bovine semen and a theoretical model to explain the fertility differences

In vitro trials on the survival of sperm stored fresh or rediluted after freezing showed quite significant differences in the total survival time of sperm incubated at 37°C. Even after adjusting for different sperm concentrations, survival was still superior in the fresh compared with rediluted frozen sperm (124 ± 5.5 h vs. 75.8 ± 3.1 h). There was no significant difference in fertility between rediluted frozen sperm (RDF) and fresh sperm, both stored in Caprogen, when the insemination dose was 20 × 10⁶ and 2.5 × 10⁶ sperm, respectively. Reduction of the sperm concentration in the insemination dose from 20 × 10⁶ to 5 × 10⁶ sperm in RDF and from 2.5 × 10⁶ to 0.5 × 10⁶ sperm in fresh semen reduced non return rates by 7.9% and 7% respectively (P < 0.001). The bull × dose rate interaction for non return rate was not significant for fresh semen, but significant for RDF (P < 0.001). Two theoretical models were used to examine the effects of freezing on the survival of sperm in the female reproductive tract and the probability of fertilisation. There is a suggestion that freezing had no effect on survival time of sperm in the female reproductive tract, but either reduced the probability of fertilisation by a single spermatozoon or altered the pattern of sperm survival in the female reproductive tract.     

Seasonal variation in the semen characteristics of Muturu (Bos brachyceros) bulls

Semen was collected by electroejaculation from seven mature Muturu bulls at weekly intervals for 9 weeks in each of three seasons (‘Dry’, ‘Rainy’, and ‘Late Rainy/Early Dry’) to study the effect of season on semen characteristics. The respective mean values for the ‘Dry’, ‘Rainy’ and ‘Late Rainy/Early Dry’ seasons were: volume 1.8 ± 0.1, 2.3 ± 0.1 and 2.0 ± 0.1 ml; percentage motility 36.2 ± 2.6, 37.7 ± 2.8 and 27.5±2.9; and percent morphologically normal sperm 70.0 ± 3.1, 79.1 ± 2.6 and 79.8 ± 2.3. No seasonal differences were found for sperm concentration/ml (overall mean 1.92 ± 0.16 × 10⁸) and for sperm output/ejaculate (overall mean 4.14 ± 0.39 × 10⁸). The chemical composition of seminal plasma (mg %) for the respective seasons was calcium: 4.8 ± 1.0, 7.9 ± 0.9 and 2.5 ± 0.7; magnesium: 4.8 ± 0.4, 4.3 ± 0.7 and 2.5 ± 0.7; and chloride: 330.7 ± 33.7, 136.0 ± 9.6 and 344.3 ± 31.8. No seasonal differences were found in sodium or potassium concentrations. Fructose was found in the semen of only one bull and only during the ‘Dry’ season.     

Human Semen Refrigeration at + 4 °C: Bio-kinetic Characteristics

The aim of our study was to evaluate the bio-kinetic characteristics of human semen refrigerated for different periods and to compare the effects of refrigeration at +4 °C against cryopreservation of human sperm at −196 °C. Semen was obtained from 30 male partners of infertile couples (infertile subjects) with the following semen profile: sperm count ≥10 × 10⁶/ml; progressive motility ≥20%; atypical forms <70% and white blood cells <1.0 × 10⁶/ml. Fifteen normospermic subjects were also selected as controls (control subjects). The following tests were carried out on basal, refrigerated and cryopreserved sperm: a) sperm kinetic properties (by Superimposed Image Analysis System); b) the Hypoosmotic Viability Test (HVT) (combined Hypoosmotic Swelling and Viability Test). The results of the study showed that the percentage recovery of kinetic properties and of HVT were optimum for up to 48 h. After refrigeration for 72 h, a drastic decrease in straight motility recovery was observed. No significant differences were observed between cryopreservation and refrigeration at +4 °C for 48 h for motility or HVT recoveries in samples from control subjects. However, in infertile subjects, a significant decrease in straight progressive motility and HVT recoveries was observed in cryopreserved samples compared to those refrigerated for 48 h. Neither refrigeration nor cryopreservation led to the growth of pathogenic bacteria in any of the cases studied. Based on the above results, refrigeration could represent a useful alternative to the cryopreservation method.     

Effect of dilution rate on feline urethral sperm motility,viability, and DNA integrity

This study was designed to investigate if the characteristics of feline urethral sperm can be affected by high dilution in an artificial medium. The semen collected by urethral catheterization from eight male cats was evaluated for sperm concentration and motility and subsequently diluted with a TRIS-based extender to the concentration of spermatozoa 10 × 10⁶/mL, 5 × 10⁶/mL, and 1 × 10⁶/mL. Immediately after the extension samples were assessed for motility, cell viability using SYBR-14 and propidium iodide, acrosome integrity using lectin from Arachis hypogaea Alexa Fluor 488 Conjugate, and propidium iodide and chromatin status by acridine orange. Compared with 10 × 10⁶/mL dilution rate, spermatozoa diluted to 1 × 10⁶ sperm/mL had a significantly lower proportion of motile (31.1% ± 19.8 and 0.7% ± 1.6, respectively, P < 0.05) and viable spermatozoa (88.3% ± 3.1 and 69.1% ± 12.8, respectively, P < 0.01). There was no dilution-related difference in the acrosome integrity (76.7% ± 11.9 vs. 75.9% ± 10.6) and chromatin status (defragmentation index, 3.3% ± 0.97 vs. 3.4% ± 1.7). These results indicate that feline urethral semen is susceptible to high dilution rate, and some sperm characteristics can be artifactually changed by semen dilution. It also suggests the potential role of seminal plasma in maintaining sperm motility and viability in high dilution rates.     

Effect of Uremia on Semen Quality and Reproductive Function in Humans

In this study, we sought to evaluate the effect of uremia on semen quality and reproductive function in humans. For this purpose, 53 end-stage uremic patients were randomly selected. The semen samples were produced by masturbation. Fertility index (FI) was calculated according to the following formula: sperm density (×10⁶/ml) × sperm motility (%) × normal sperm morphology rate (% per 10,000). The semen samples of uremic patients were compared with those of fertile and infertile males. The results show that three patients failed to produce semen. There were no sperm found in four semen samples. The sperm motility, survival rate, sperm density, and normal sperm morphology rate of the remaining 46 patients were found to be significantly lower than those of controls. The uremic patients had the FI of 0.68(2.08) which was obviously lower than that of fertile 7.7(13.51) and infertile 4.13(5.77) males. It was, therefore, concluded that uremia caused a significant decline in sperm quality and reproductive function which resulted in consequential infertility in humans.     

Persistence of spores of Pleistophora schubergi (Cnidospora: Microsporida) in the field,and their application in microbial control

Spores of Pleistophora schubergi, when applied to oak trees in the field at 2 × 10⁸ spores/ml with a uv protectant, “Shade,” infected 88% of Anisota senatoria larvae at 4 days after spray application. Spores without the uv protectant infected only 10% of the larvae at 4 days after application. When the spores were applied at the rate of 2 × 10⁸ and 2 × 10⁷ spores/ml in the field, 96 and 72% of the A. senatoria larvae and 100 and 100% of the Symmerista canicosta larvae were infected 14 days after spray application.     

Fertilization of cumulus-free,zona-intact mouse ova in vitro at high and low sperm concentrations

The effect of varying the sperm concentration between 2 × 10⁵ sperm/ml and 8 × 10⁶ sperm/ml on fertilization of cumulus-free, zona-intact F1 (CBA × C57BL) mouse ova by QS and F1 (CBA × C57BL) mouse spermatozoa was studied. The spermatozoa from both strains of mice exhibited optimal fertilization rates at 2 × 106 sperm/ml. However, at sperm concentrations greater than 4 × 106 sperm/ml and less than 1 × 106 sperm/ml, fertilization rates were significantly reduced. F1 spermatozoa were more susceptible to dilution than QS spermatozoa. A significant interaction between strain and sperm concentration indicated that the two strains produced different fertilization rates at different sperm densities. Extracts of epididymal fluid, medium from capacitated spermatozoa, or ampulla fluid did not improve the fertilization rate at 2 × 105 sperm/ml, but retaining the cumulus oophorus did. The decrease in fertilization rate at 8 × 106 sperm/ml can in part be attributed to a nondialysable inhibitor from the neat sperm preparation that appeared to be of epididymal origin.     

Effect of Dietary Selenium and Vitamin E on Ganders’ Response to Semen Collection and Ejaculate Characteristics

Compared to other domestic bird species, geese exhibit the lowest reproductive efficiency (poor semen quality, low egg production, and poor fertility and hatchability rates). From an economic perspective, it is a necessity of improve these reproductive traits. Studies have demonstrated that the essential trace element—selenium—plays key roles in testicular development and the maintenance of spermatogenesis. The aim of the present study was to determine the effect of feed supplementation with organic selenium and vitamin E on ganders’ response to manual semen collection and semen quality. Sixteen 3-year-old White Koluda ganders were randomly divided into two groups. The control group was provided commercial feed while the experimental group was provided with the same commercial feed supplemented with selenium (0.3 mg/kg) and vitamin E (100 mg/kg). The response of individual ganders from both groups to manual semen collection and the quality of the semen collected were evaluated. The supplements increased (P?≤?0.05) the frequency and decreased the time interval of a complete ejaculatory response of the ganders to manual semen collections (82.7 % supplement vs. 73.5 % control). Males from the supplemented group had significantly higher (P?≤?0.01; P?≤?0.05) ejaculate volumes, sperm concentrations, and percentages of viable sperm and lower percentages of immature sperm (spermatids). Lipids peroxidation, expressed in terms of the malondialdehyde concentration, was lower (P?≤?0.01) in semen of the supplemented group (0.172 nmol/50?×?10⁶) as compared to the controls (0.320 nmol/50?×?10⁶). Moreover, the duration of the reproductive period of the ganders in the experimental group was 1 week longer. The results show that supplemental dietary selenium and vitamin E improved both the ganders’ response to manual semen collection and semen quality. We conclude that such feed supplementation could lead to greater economic benefits through increased reproductive efficiency within the goose production industry.     

Sperm loss using different artificial vaginas in rams

The objective of the present study was to evaluate the effect of certain factors on sperm loss during ram semen collection, using an artificial vagina (AV). The factors analyzed were the effect of the male (8 rams), length of the artificial vagina (short versus long), order of the ejaculate (first versus second ejaculate) and lubrication technique (with or without lube). An observational study from a data set containing 55 semen collections from the 8 rams of different breeds (Montadale, Suffolk, Hamphshire, Polypay) were evaluated during the breeding season using a multiple regression statistical analysis over a period of 10 weeks. The results did not show any differences between rams, order of the ejaculate or the use of lubrication on sperm loss. The two types of artificial vaginas however showed significant differences in the percentage sperm loss (P < 0.001). The total ejaculate volume (collection tube volume + liner and cone recovery volume) and sperm concentration/ml (×10⁹) were similar when using the two types of artificial vaginas. The total ejaculate volume recorded for the short artificial vagina was 1.5 ± 0.4 ml and for the long artificial vagina was 1.3 ± 0.6 ml. The concentration of the ejaculate was 2.7 ± 0.6 × 10⁹ sperm/ml for the short artificial vagina and 2.9 ± 0.7 × 10⁹ sperm/ml for the long artificial vagina. The volume of semen in the collection tube using the short artificial vagina was 1.3 ± 0.4 ml, compared to the 0.7 ± 0.5 ml for the long artificial vagina (P < 0.001). The percentage of sperm loss from the short artificial vagina (12.9 ± 5.9%) was significantly lower than when using the long artificial vagina (50.8 ± 13.9%; P < 0.001). From this study, it may be concluded that the type of artificial vagina affects the sperm loss; with the shorter AV recording a lower sperm loss. No effects were detected between rams, order of the ejaculate or the use of lubrication on sperm loss. From the results obtained the use of the short artificial vagina can be recommended.     

Effects of Nigella sativa L. seed oil on abnormal semen quality in infertile men: A randomized,double-blind,placebo-controlled clinical trial

In recent years, wide utilization of herbal drugs has encouraged scientists to determine their impressive effects on health. Since Nigella sativa L. seed (N. sativa) has many uses including infertility in traditional medicine, the effects of Nigella sativa L. seed oil on abnormal semen quality in infertile men with abnormal semen quality are of interest. This study was conducted on Iranian infertile men with inclusion criteria of abnormal sperm morphology less than 30% or sperm counts below 20 × 10⁶/ml or type A and B motility less than 25% and 50% respectively. The patients in N. sativa oil group (n = 34) received 2.5 ml N. sativa oil and placebo group (n = 34) received 2.5 ml liquid paraffin two times a day orally for 2 months. At baseline and after 2 months, the sperm count, motility and morphology and semen volume, pH and round cells as primary outcomes were determined in both groups. Results showed that sperm count, motility and morphology and semen volume, pH and round cells were improved significantly in N. sativa oil treated group compared with placebo group after 2 months. It is concluded that daily intake of 5 ml N. sativa oil for two months improves abnormal semen quality in infertile men without any adverse effects.     

E-rosette formation at 37 °C: Analysis with monoclonal OKT antibodies

When cultured in the presence of PHA, a proportion of human peripheral blood mononuclear cells acquires the capacity to form E rosettes with sheep erythrocytes that are resistant to incubation at 37 °C. The nature of this 37 °C stable E-rosette formation was investigated using a panel of monoclonal OKT antibodies directed to human T-lymphocyte surface antigens. OKT11A antibody, at a concentration of 0.2–0.4 μg/ml, markedly blocked 37 °C E rosetting. OKT1, OKT3, OKT4, OKT6, and OKT8 antibodies, when tested at 10 μg/ml, show no such inhibiting activity. Quantitative studies with ¹²⁵I-labeled OKT11A indicated that the antibody interacted strongly with both 37 °C E-rosetting and nonrosetting cells, the association constant being 1.6–2.0 × 10⁹M^?1. However, on the average, a threefold higher concentration of OKT11A receptor sites was found on 37 °C E-rosette-forming cells (14.8 × 10⁴ sites/cell) than on nonrosetting cells (4.8 × 10⁴ sites/cell). Our data suggest that 37 °C E-rosette formation is governed by a lymphocyte surface determinant recognized by OKT11A antibody. “Overexpression” of OKT11A antigenic sites on a proportion of PHA-stimulated lymphocytes may explain their capacity to form 37 °C stable E-rosettes.     

Artificial insemination of sheep: the fertility of semen extended in diluents containing egg yolk and inseminated soon after dilution or stored at 5 degrees C for 24 or 48 hours.

In an experiment involving the artificial insemination (AI) of 1175 ewes, ram semen was diluted 10- or 30-fold in a buffered glucosesaline solution containing either 1.5% or 6% (v/v) egg yolk. Part of each semen collection was used undiluted for control AI of 10⁸ sperm/dose. Diluted samples were reconcentrated to 10⁹ sperm/ml by centrifugation and, from these preparations, 10⁸ spermatozoa were inseminated in a standard volume of 100 μl. Fertility was assessed by 28–45 day non-returns to oestrus.The processes of dilution and reconcentration caused a significant drop in the non-return rate (NRR) and cooling to 5°C and storage for up to 48 hrs at this temperature gave a further large, and highly significant, reduction in NRR. There was no significant effect of level of egg yolk in the diluent on NRR.     

Fertility of ram semen after storage at 5°C

In five experiments, fertilization, early (18–19-day) pregnancy, and lambing were examined after insemination with semen stored at 5°C in tris-fructose-egg yolk diluent.After deposition into uterine horns by surgical insemination of semen stored for 0 (control), 2, 4, 6, 8, 9 or 10 days, fertilized eggs were recovered in $\text{32}\text{34}\text{,}\text{16}\text{16}\text{,}\text{21}\text{22}\text{,}\text{15}\text{20}$, $\text{9}\text{17}\text{,}\text{2}\text{18}$ and $\text{1}\text{15}$ ewes; the 18–19-day pregnancy rates determined by progesterone assay were $\text{32}\text{48}\text{,}\text{15}\text{28}\text{,}\text{11}\text{20}\text{,}\text{12}\text{20}\text{,}\text{9}\text{20}$, $\text{2}\text{20}$ and $\text{1}\text{21}$ for the respective storage periods. There was a linear decrease in fertilization rates beyond 4 days of storage and in early pregnancy rates after 6 days of storage (P<0.001). The decline with time of storage in the fertilization rate was not associated with an increase in early embryonic loss. Surgical insemination with semen stored for 0, 4, 6, 8, 9 and 10 days resulted in 53, 35, 40, 25, 5, and 0% lambing.Single cervical (normal) insemination of a total of 281 ewes with 0, 1, 2 or 3-day-old semen, using within each semen treatment 90 × 10⁶ and 180 × 10⁶ spermatozoa, yielded mean lambing rates of 60.0, 34.3, 33.8, and 17.1%; and after using 150 × 10⁶ and 300 × 10⁶ spermatozoa in a total of 393 ewes the mean lambing rates for the above semen treatments were 69.0, 46.4, 36.1, and 24.2% (linear, P < 0.001). In both tests the lambing results were better after insemination of the higher number of spermatozoa, but the slope of decline in fertility with age of semen was not affected by the sperm dose.When single and double cervical inseminations were performed in a total of 411 ewes, with 150 × 10⁶ and 300 × 10⁶ spermatozoa per inseminate, the lambing rates for semen stored for 0, 1, 2 and 3 days were 57.7, 30.4, 26.8, and 4.7% after single insemination, and 66.7, 56.8, 46.4, and 41.5% after double inseminations. The sperm dose within method of insemination and semen treatment had no effect. The lambing rate was better after double than single insemination (P<0.001), but the slope of decline in fertility with age of semen was not significantly affected by number of inseminations.In the final experiment, involving 408 ewes, 300 μg of prostaglandin F₂α added to the inseminate did not improve the fertility of fresh semen or semen stored for 1 day.     

The influence of the length of time after hormonal treatment with [(d‐Ala6, Pro9 NEt)‐mGnRH+metoclopramide] i.e. Ovopel on barbel Barbus barbus (L.) milt quality and quantity indicators

The study purpose was the analysis of barbel Barbus barbus (L.) milt quality and quantity with regard to the time following stimulation with [(D‐Ala⁶, Pro⁹NEt)‐mGnRH+metoclopramide] i.e. Ovopel. Selected parameters such as total volume of milt (TVM, ml), volume of milt per kg of body weight (VOM, ml kg^?1 b.w.), sperm concentration (×10⁹ ml^?1), total sperm production (TSP, ×10⁹), osmolality (mOsm kg^?1) and pH of seminal plasma were determined. Sperm motility was analyzed by the CASA system, i.e. the percentage of sperm motility (MOT, %) and their progressive motility (PRG, %), curvilinear velocity (VCL, μm s^?1) and straight line velocity (VSL, μm s^?1), amplitude of lateral head displacement (ALH, μm), and beat cross frequency (BCF, Hz). Milt was collected from 12 specimens (N = 12), with the first portion obtained 12 h following treatment with Ovopel (1 granule kg^?1 b. w.). Subsequent portions of milt were taken at 24 h intervals, i.e. after 36, 60, 84, 108, and 132 h. The control group (Control, N = 12) was injected with 0.9% NaCl at 0.5 ml kg^?1b.w. from which milt was taken 12 h post injection. The highest TVM, VOM and TSP values were recorded 12 h after Ovopel treatment (3.2 ± 0.7 ml, 36.7 ± 10.5 ml kg^?1 b.w. and 39.1 ± 9.4 × 10⁹, respectively); lowest values were recorded after 132 h (0.8 ± 0.4 ml, 11.1 ± 6.5 ml kg^?1b.w. and 13.7 ± 7.5 × 10⁹, respectively). The highest seminal plasma osmolality values (300.0 ± 42.6 mOsm kg^?1) as well as the lowest sperm concentration (12.5 ± 1.5 × 10⁹ ml^?1) were observed 12 h after Ovopel treatment. No significant differences in the percentage of sperm motility (MOT) were noted during any of the periods after hormonal stimulation, however, a change in the character of their movement (PRG) was observed. The lack of significant differences (P > 0.05) in VCL and VSL values between 12 h and 60–132 h indicates that the lengthening of time does not lead to a decrease in sperm velocity and, therefore, is not likely to have a negative impact on their quality. The highest ALH (1.9 ± 0.2 μm) and BCF (11.5 ± 1.1 Hz) values were observed when the effect of stimulation was most noticeable, i.e. 12 h after Ovopel treatment. Based on the total milt volume and sperm production, the best time for milt collection from barbel is 12 h post‐hormonal treatment; 84 h post‐hormonal treatment, TVM, VOM, TSP and some CASA parameters decreased, which suggest the same aging process in sperm.