Increased Sperm Production Research Articles

The effects of crude extract of Amaranthus hybridus (000059604) on reproductive parameters of the male Wistar rats

Studies on Amaranthus hybridus (AH) have established its antioxidant properties. This study investigated the effects of AH on some reproductive parameters of forty-five sexually matured Albino rats (Wistar Strain) males. Amaranthus hybridus has been reported to have several protective and curative properties attributed majorly to strong antioxidant activity. They were randomly grouped into 3 with each group consisting of 15 rats. Group A received (per Os) Amaranthus hybridus (50mg/kg body weight) and group B had Amaranthus hybridus (100mg/kg body weight for 7 days. Group C (control) received distilled water for 7 days. Blood and semen samples were collected for analyses on day 1,8,15 and 22 post-treatments. The results showed that the sperm motility of group B in day 1, (2.00± 2.00%) rat was significantly lower (p < 0.001) than that of group C (26.00 ± 7.97%), whereas it was greatly improved in Group B (85.00 ± 4.47%) and Group A (60.00 ±4.47%) at the day 22 posttreatment. Livability of sperm cells were significantly higher (p < 0.5 0) in Group A (96.20±0.73%) and Group B (96.20±0.73%) compared to Group C (96.80±1.64%) at day 22 post-treatment. The histology of the testis of control and all treatment groups revealed normal testicular germinal epithelium full of viable spermatogenic cells. It is, therefore, concluded that Amaranthus hybridus extract given orally at 50mg/kg and 100mg/kg body weight, did not affect the normal cytoarchitecture of the testis and epididymis and can increase sperm production.

Increased sperm production linked to competition in the maternal social environment.

Maternal or early life effects may prepare offspring for similar social conditions to those experienced by their mothers. For males, the ability to achieve mating and fertilization success is a key social challenge. Competitive conditions may therefore favour increased body size or ejaculate production in male offspring. We tested this experimentally by comparing reproductive traits of adult male bank voles (Myodes glareolus), whose mothers had experienced contrasting encounter regimes with female conspecifics while breeding. We found that daily sperm production rates and epididymis mass were significantly higher when dams had experienced more frequent encounters with female conspecifics. This response to maternal and early life experience was specific to sperm production and storage, with no evidence for effects on male body mass or the size of testes and accessory reproductive glands. Our findings reveal a potentially adaptive effect of maternal and early life experience on the development of sperm production, which is worthy of wider investigation.

SAT-032 Follistatin-Like 3 (FSTL3) and Early Postnatal Testicular Development

Activin, a TGFβ family ligand, induces Sertoli cell (SC) proliferation during the early postnatal stage in mice. Overexpression of activin, however, leads to the disruption of spermatogenesis. FSTL3, a glycoprotein inhibitor of activin, is highly expressed in the testis and its expression is induced by activin creating an inhbitory feedback loop. FSTL3 deletion in mice is therefore expected to produce a mouse model of increased activin action. Contrary to overexpression of activin, however, as we have shown before, global deletion of FSTL3 in mice results in increased numbers of SC and increased sperm production in older males. Stereological analyses show that although the overall number of SC increases with age in both genotypes during pre-pubertal stages, increase in SC numbers is significantly higher in FSTL3 KO males. Here we show our transcriptomic analyses of WT and FSTL3 KO mice at 3d and 8wk. mRNA sequencing data showed that more than 1000 genes are diffferentially regulated between WT and FSTL3 KO at 3d. There is a much lower number of genes differentially expressed at 8wk. Among several canonical pathways that are altered at 3d in FSTL3 KO mice compared to WT we investigated the “Sertoli-to-Sertoli cell Communication” pathway. We found increased expression of junction proteins, including those that are involved in the blood testis barrier (BTB) as well as earlier establishment of BTB in FSTL3 KO testis. Without the BTB, preleptotene spermatocytes cannot progress through the spermatogenic programme. Importantly, we found accelerated SYCP3 organisation, indicative of early entry into meiosis, concomitant with early establishment of BTB. To directly address whether FSTL3 deletion can induce SC proliferation we knocked down FSTL3 expression in the TM4 SC line. We found increased PCNA expression with FSTL3 siRNA compared to control siRNA transfection demonstrating FSTL3 impairment does induce SC proliferation. We are currently investigating the mechanisms for early establishment of BTB in FSTL3 KO testes and additional canonical pathways. The results of the study presented suggests that loss of FSTL3 promotes SC proliferation which likely allows establishment of SC-SC interactions including BTB formation earlier than in WT. Given that the difference in size between WT and FSTL3 KO testis persists at older ages, it is possible that the timing of increase in SC number and establishment of BTB has a sustained effect on testicular function later in life.

Prospects for FSH Treatment of Male Infertility.

Despite the new opportunities provided by assisted reproductive technology (ART), male infertility treatment is far from being optimized. One possibility, based on pathophysiological evidence, is to stimulate spermatogenesis with gonadotropins. We conducted a comprehensive systematic PubMed literature review, up to January 2020, of studies evaluating the genetic basis of follicle-stimulating hormone (FSH) action, the role of FSH in spermatogenesis, and the effects of its administration in male infertility. Manuscripts evaluating the role of genetic polymorphisms and FSH administration in women undergoing ART were considered whenever relevant. FSH treatment has been successfully used in hypogonadotropic hypogonadism, but with questionable results in idiopathic male infertility. A limitation of this approach is that treatment plans for male infertility have been borrowed from hypogonadism, without daring to overstimulate, as is done in women undergoing ART. FSH effectiveness depends not only on its serum levels, but also on individual genetic variants able to determine hormonal levels, activity, and receptor response. Single-nucleotide polymorphisms in the follicle-stimulating hormone subunit beta (FSHB) and follicle-stimulating hormone receptor (FSHR) genes have been described, with some of them affecting testicular volume and sperm output. The FSHR p.N680S and the FSHB -211G>T variants could be genetic markers to predict FSH response. FSH may be helpful to increase sperm production in infertile men, even if the evidence to recommend the use of FSH in this setting is weak. Placebo-controlled clinical trials, considering the FSHB-FSHR haplotype, are needed to define the most effective dosage, the best treatment length, and the criteria to select candidate responder patients.

Repeated hormonal induction of spermiation affects the stress but not the immune response in pikeperch (Sander lucioperca)

Hormonal induction of spermiation, previously reported to be immunogenic in fishes, is a common hatchery practice in pikeperch, Sander lucioperca. The aim of the present study was to investigate the effects of repeated induction of spermiation in pikeperch, following application of either human chorionic gonadotropin (hCG) or salmon gonadoliberine analogue (sGnRHa) on sperm quality indices as well as on immune and stress response. Mature males of pikeperch (n = 7 per group) were stimulated twice with five days between injections of either hCG (hCG; 500 IU kg−1), sGnRHa (sGnRHa; 50 μg kg−1) or NaCl (control group; 1 ml kg−1) to assess spermatozoa motility with a computer-assisted sperm analysis (CASA) system. During second sampling, blood plasma was sampled for humoral innate immune (peroxidase and lysozyme activities, ACH50), stress (cortisol, glucose) and endocrine (testosterone) markers. In addition, the head kidney was dissected to assay the expression of several immune genes (such as il1, c3, hamp, tnf-α and lys genes). The results indicate that hormonal treatment significantly increased sperm production. Sperm sampled after the hormonal treatment maintained its quality throughout the study, regardless of the sampling time. However, it appears that the application of hCG induced elevated cortisol and glucose plasma levels compared to the control group. Almost all immune markers, except the relative expression of hepcidin (hamp gene), were unaffected by the two hormones applied. The results showed that the induction treatment of spermiation processes in pikeperch resulted in an important physiological stress response for which the intensity varied according to the hormonal agent used. However, this stress response (more profound following application of hCG) was weakly associated with innate immune functions. On the other hand, a significant negative correlation between the expression of several important immune markers (peroxidase activity, relative expression of c3 and il1 genes) and sperm quality indices indicates significant involvement of immune status on sperm quality. The results obtained shed light on immune-system-induced modifications to sperm quality. The data presented here highlight the need for careful revision of broodstock management and selection practices where welfare status as well as individual predispositions of fish to cope with the stress should be taken under the consideration.

Strategic ejaculate adjustments and mismatches: are males paying sperm senescence costs?

In many species, males show anticipatory plasticity for sperm production, which they adjust to match perceived mating opportunities. While the strategic adjustment of sperm production is likely to be beneficial, it may be also associated with costs, including those arising from the expression of a phenotype that is poorly matched to the conditions that males will subsequently experience. Mismatch costs are exacerbated by trade-offs between investment in the ejaculate and investment in other traits and by trade-offs among individual ejaculate traits. Trade-offs, in fact, may determine a decrease in male competitiveness, due to impaired ability to obtain copulations or to reduced ejaculate quality. We explored mismatch costs using male guppies, which are known to increase sperm production, but reduce their investment in sexual behaviour, when maintained in the presence of females. Increasing ejaculate size in the absence of females could impose costs that would be paid when an opportunity to mate eventually arises. One of such costs may involve male post-copulatory competitiveness and may be associated with increased sperm senescence. To explore mismatch costs, firstly we induced two groups of males to differentiate their sperm production by exposing them or not to female stimuli. Then, we isolated them to prevent matings and have their sperm ageing. Finally, we compared ejaculate quality between the groups. Contrary to expectations, we found that female-stimulated males did not suffer from increased sperm senescence. These costs are probably minimized by the high level of plasticity associated with this trait, resulting in sperm production being quickly re-adjusted to a new environment. Other types of mismatch costs may be more relevant, for example, those related to trade-offs with sexual behaviour.

Sertoli cell proliferation in juvenile boars and microRNA

Sertoli cell numbers are a major influence on sperm production capacity. Increased use of artificial insemination and the limited number of insemination doses from a single boar ejaculate provide the incentive to increase Sertoli cell numbers for potential increases in sperm production and pig production efficiency. Although the number of Sertoli cells can be at least temporarily manipulated in vivo, the mechanism for the increased proliferation is poorly understood and critical for development of practical production practices. MicroRNAs are recognized to regulate many genes during development. Recent work suggested specific microRNAs were involved with regulation of Sertoli cell lines maintained in monoculture. In order to evaluate the relationship of specific microRNAs (miR-26a, miR-196a, miR-499, miR-638 and miR-1285) to in vivo Sertoli cell proliferation, three in vivo models of increased Sertoli cell proliferation (hemicastration, reduced androgen signaling, and reduced endogenous estrogen synthesis) were evaluated in young juvenile boars. Hemicastration was associated with slightly decreased miR-26a, similar to the decrease associated with in vitro Sertoli cell monoculture but none of the other microRNAs were affected by hemicastration nor were any affected by the blockade of androgen signaling with flutamide. Decreased expression of miR-638 followed reduced endogenous estrogen synthesis consistent with in vitro results although expression of miR-1285 was the converse from the in vitro results. Alterations in specific microRNAs are associated with increased Sertoli cell proliferation. However, altered expression of microRNAs was specific to the particular model system, suggesting unique molecular pathways are involved.

Combination of Korean Red Ginseng Extract and Hydrogen-Rich Water Improves Spermatogenesis and Sperm Motility in Male Mice.

To investigate the effect of hydrogen-rich Korean Red Ginseng (KRG) water (HRGW) mixture on the spermatogenesis and sperm motility of mice of different ages. Eighty young (3 month-old) and aged (12 month-old) male mice were randomly assigned to 4 groups (n =10 per group) including control group, hydrogen-rich water (HRW) group (10 mL/kg daily), KRG group (50 mg/kg daily) and HRGW group (10 mL/kg and 50 mg/kg daily) by an oral zoned needle for 4 weeks. Sperm count and motility were measured using sperm suspension released from cauda epididymis. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and reactive oxygen species (ROS) in serum have also been estimated. Tubular changes were examined through histological hematoxylin and eosin staining. Expression of antioxidation (PPx3, PPx4, GSTm5 and GPx4), spermatogenesis (inhibin-a, neptin-2 and CREM), antiaging (SIRT1 and SIRT2), and angiogenesis [visfatin and vascular endothelial growth factor (VEGF)] related genes were examined through real-time polymerase chain reaction. HRW and KRG treatment stimulated spermatogenesis followed by increasing sperm production and sperm motility (P <0.05). These effects were strengthened synergistically by a HRGW mixture (P <0.05 or P <0.01). HRGW greatly increased the expressions of antioxidation, antiaging, spermatogenesis related genes and VEGF especially in aged mice (P <0.05). Serum testosterone and FSH levels also increased, while serum ROS level decreased (all P <0.05). HRGW increases sperm production and motility by enhancing antioxidation and stimulating spermatogenesis and sex hormone production, particularly in aged mice.

Effectiveness of using Elevit feed additive in pig feeding

In a number of experiments, adding of Elevit feed additive in the amount of 100, 150, 200, or 250 grams per day to the basic ration of breeding boars helps to increase sperm production by 5.0, 8.6, 11.9, and 11.1% in comparison with the control group of boars. In the boars of experimental groups, qualitative parameters of sperm increased as following: sperm resistance by 6.6, 8.1, 12.3, and 11.9%; the ability of sperm cell to live outside the body by 6.0, 6.7, 7.4, and 8.1% in comparison with the control group.Adding this drug at the dose of 50, 100, 150, and 200 g to the basic diet of sows during the period of their preparation to insemination has a favorable effect on increasing the following parameters: sexual heat by 5.0, 10.0, 10.0, and 10.0%; productive insemination by 1.0, 7.1, 1.9, and 7.1%; number of piglets in a litter by 2.8, 6.6, 7.6, and 5.7% in comparison with the control group.

DNA methylation stability in fish spermatozoa upon external constraint: Impact of fish hormonal stimulation and sperm cryopreservation.

Highly differentiated mature spermatozoa carry not only genetic but also epigenetic information that is to be transmitted to the embryo. DNA methylation is one epigenetic actor associated with sperm nucleus compaction, gene silencing, and prepatterning of embryonic gene expression. Therefore, the stability of this mark toward reproductive biotechnologies is a major issue in animal production. The present work explored the impact of hormonal induction of spermiation and sperm cryopreservation in two cyprinids, the goldfish (Carassius auratus) and the zebrafish (Danio rerio), using LUminometric Methylation Assay (LUMA). We showed that while goldfish hormonal treatment did increase sperm production, it did not alter global DNA methylation of spermatozoa. Different sperm samples repeatedly collected from the same males for 2 months also showed the same global DNA methylation level. Similarly, global DNA methylation was not affected after cryopreservation of goldfish spermatozoa with methanol, whereas less efficient cryoprotectants (dimethylsulfoxide and 1,2-propanediol) decreased DNA methylation. In contrast, cryopreservation of zebrafish spermatozoa with methanol induced a slight, but significant, increase in global DNA methylation. In the less compact nuclei, that is, goldfish fin somatic cells, cryopreservation did not change global DNA methylation regardless of the choice of cryoprotectant. To conclude, global DNA methylation is a robust parameter with respect to biotechnologies such as hormonal induction of spermiation and sperm cryopreservation, but it can be altered when the best sperm manipulation conditions are not met.

Prepubertal PTU treatment in rat increases Sertoli cell number and sperm production.

The number of Sertoli cells (SCs) ultimately determines the upper limit of sperm production in the testis. Previous studies have shown that thyroid hormones (TH) receptors are abundantly expressed in developing SCs; therefore, it was highly significant to discover that transient neonatal hypothyroidism induced by the goitrogen 6-n-propyl-2-thiouracil (PTU) can extend SCs proliferation beyond the first 2 weeks postnatal and increase testis weight and sperm production. Further studies concluded that treatment must begin before day 8 post birth in rats. Recent studies, however, showed that SCs present in the transition region at the rete testis exhibit a more immature phenotype and have prolonged mitotic activity, which led to the hypothesis that SCs in this region will retain the capacity to respond to PTU treatment over a longer period of time. In the present study, male Wistar rats were treated with PTU from days 21 to 40 and were evaluated at 40 and 160 days of age. Similar to neonatal rat SCs, it was demonstrated that prepubertal SCs in the transition region have a high mitotic activity and are highly sensitive to TH levels. This delayed, transient hypothyroidism resulted in significantly increased testis weight, SCs number and daily sperm production. The results demonstrate for the first time that Sertoli cells showing plasticity in the transition region can be stimulated to increase proliferation and contribute to a late stage surge in testis weight and sperm output.

Functional role of GKAP1 in the regulation of male germ cell spontaneous apoptosis and sperm number.

G kinase-anchoring protein 1 (GKAP1) is a G kinase-associated protein that is conserved in many eutherians and is mainly expressed in the testis, especially in spermatocytes and round spermatids. The function of GKAP1 in the testis is largely unknown. Here, we revealed that deletion of GKAP1 led to an increase in sperm production with swollen epididymis, and germ cell apoptosis was found to decrease in GKAP1 knock-out mice. Further investigations showed that a deficiency of GKAP1 could partly change the cellular location of cGK-Iα and increase the amount of active cAMP response element-binding protein (CREB) in the nucleus. Therefore, the expression of a particular inhibitor of apoptosis proteins (IAPs) was upregulated because of the activation of CREB, and this increase in IAPs was associated with a decrease in the level of activated caspase-3. These results suggest that a deficiency of GKAP1 in mouse testis could increase sperm production through a reduction of the spontaneous apoptosis of germ cells in the testis, possibly because of a change in the activity of the cGK-Iα pathway.

SUN-218 The Role Of Fstl3 In Spermatogenesis: A Transcriptome Analysis

Spermatogenesis in mammals depends on the function of Sertoli cells (SC). The total number of SC present in the testes is determined in the pre-pubertal stages of development. Activin, a TGFβ family ligand, regulates SC proliferation in the early postnatal phase in mice. During this phase immature SC are unable to assemble tight-junctions which are required to form the blood-testis-barrier (BTB) and consequently do not support spermatogenesis. Overexpression of activin beyond pre-pubertal stages results in the disruption of spermatogenesis and results in infertility. Follistatin Like-3 (Fstl3) is a glycoprotein known to bind and inhibit activin. Contrary to overexpression of activin, however, global deletion of Fstl3 in mice results in increased numbers of SC and increased sperm production in older males. Based on this striking observation, in this study, using the global deleted Fstl3 mouse model, we sought to elucidate the function of Fstl3 in testicular development during the transition from pre-pubertal to post-pubertal stages. In testis sections from BrdU treated Fstl3 KO mice, we found that SC number per tubule is maintained from pre-pubertal to post-pubertal stages without a concomitant increase in BrdU positive SC. In contrast, SC numbers in similarly treated WT mice are depleted over the same time period. Stereological analyses further show that although the overall number of SC increases in both genotypes during pre-pubertal stages, increase in SC numbers is significantly higher in Fstl3 KO males. We also found by immunofluorescence that Sycp3 organization appears early (postnatal day 7) in Fstl3 KO mouse testes indicating early meiotic entry. To identify signalling pathways associated with SC proliferation and maturation that are affected by Fstl3 deletion we performed total mRNA sequencing and compared the findings between WT and Fstl3 KO testes of 3 day and 8 weeks mice. Our results show that more than 1000 genes are differentially expressed between WT and KO testes. Pathway analyses reveal that the “Sertoli-to-Sertoli cell Communication” pathway is one of the most relevant enriched canonical pathways in 3 day old Fstl3 KO mice compared to WT. We are currently investigating the mechanisms for early establishment of BTB in Fstl3 KO testes. The results of the study presented suggests that loss of Fstl3 promotes the establishment of SC-SC interactions that support spermatogenesis during the proliferative phase of these cells.

Seasonal-and dose-dependent effects of recombinant gonadotropins on sperm production and quality in the flatfish Solea senegalensis

Consecutive treatments with recombinant follicle-stimulating and luteinizing hormones (rFsh and rLh, respectively) stimulate spermatogenesis and potentiate sperm production in pubescent specimens of the oligospermic Senegalese sole (Solea senegalensis). However, sperm production in response to the hormones is highly variable, and the steroidogenic potential of the testis may be diminished due to sustained hormone supply. Here, we compared the effectiveness of low (9 μg/kg) and high (18 μg/kg) doses of rFsh and rLh to improve sperm production in adult sole during late winter-early spring (onset of the natural spawning period), and in autumn under a controlled temperature of 12 °C (period of testicular recrudescence). Treatment with rFsh over six weeks during spring, followed by a single rLh injection, did not enhance sperm production, possibly because of an advanced stage of sexual maturation of the males, as reflected by high Lh plasma levels (~17 ng/ml) before rFsh treatment. In contrast, in autumn, when the Lh circulating levels were much lower (~3 ng/ml), the low doses of rFsh and rLh generated a four-times increase in sperm production, whereas the high doses of the hormones were ineffective. However, treatment with rLh, regardless of the effect of rFsh, improved the motility of spermatozoa during both spring and autumn. These data confirm that consecutive rFsh and rLh treatments increase sperm production and quality in adult sole males, although they seem to be highly sensitive to the rFsh dose. The efficiency of recombinant gonadotropins also appears to be season-dependent despite the asynchronous nature of the sole testis.

Proximate mechanisms of the differences in reproductive success of males bearing different alleles of Pgdh - a gene involved in a sexual conflict in bulb mite.

Enzyme polymorphism in phosphogluconate dehydrogenase (Pgdh) is a striking example of single gene polymorphism involved in sexual conflict in bulb mite Rhizoglyphus robini. Males homozygous for the S Pgdh allele were shown to achieve higher reproductive success than FF homozygous males, while negatively influencing fecundity of their female partners. Here, we investigate proximate mechanisms responsible for the increased reproductive success of SS males and find that the S allele is associated with shorter time until copulation, higher copulation frequency and increased sperm production. We also show that Pgdh alleles are probably codominant, with SS males gaining the highest reproductive success, FF males - the lowest - and FS-heterozygous males taking an intermediate position in all fitness parameters differentiating males of different genotypes. Additionally, we confirm the negative effect that S-bearing males impose on the fecundity of females they mate with, showing a clear pattern of interlocus sexual conflict. We discuss that this effect is probably associated with increased copulation frequency. Whereas, contrary to what we have predicted, the S allele does not cause increased general male mobility, we speculate that the S allele-bearing males are more efficient in forcing copulation and/or detecting females.

Influences of dietary supplementation with Lepidium meyenii (Maca) on stallion sperm production and on preservation of sperm quality during storage at 5 °C

Stallion semen is damaged by oxidative stress during cooling and transport. Semen processing and extenders have been tested to improve the fertilizing capacity of semen and to preserve semen during transport. Dietary supplementation with natural antioxidants has been proposed to prevent oxidative damages. In this study, for the first time, the effect of dietary supplementation with Lepidium meyenii (Maca) on the characteristics of fresh and chilled stallion semen was evaluated. Maca is a traditional Andean crop used as a nutraceutical for the fertility-enhancing properties that are linked with antioxidant activity. The diet of five stallions was supplemented with 20g of Maca powder daily for a total of 60days. A control group of five stallions received the same diet without Maca. Semen was collected once before the administration of Maca (D0), twice during the administration at 30 and 60days (D30 and D60), and finally twice at 30 and 60days after the end of the administration (D90 and D120). Ejaculates were processed for cooled shipping at 5°C and evaluated in the laboratory for total and progressive motility, acrosome integrity, and lipid peroxidation after collection and after 24, 48, and 72h of storage. Dietary supplementation with Maca improved sperm concentration (from 213±80.4 to 447±73.1×106 spz/mL) and total sperm count (from 10,880±4377 to 24,783±4419×106 spz). The beneficial effects of Maca supplementation on motility and acrosome integrity in the raw semen were detected from the end of treatment with Maca (D60) until the end of the study (D120). Furthermore, during cooling storage, total motility, progressive motility, and acrosome integrity declined more slowly in the Maca-treated group than in the control group. Lipid peroxidation did not change during cooling storage in either group and did not show a significant difference between the two groups. In this study, the dietary supplementation with Maca increased sperm production and stabilized semen quality during chilled storage.

Multiple collections of common carp Cyprinus carpio L. semen during the reproductive period and its effects on sperm quality

Multiple collections of semen during the reproductive period of the common carp Cyprinus carpio L. were used to analyse changes in semen quality. Semen collection was performed on June 1 (first collection), 12 (second collection), and 19 (third collection) from individual males (n=11) by gentle abdominal massage. Semen quantity (semen volume and sperm count), quality (sperm motility and sperm viability), as well as seminal plasma parameters (pH of seminal plasma and seminal plasma osmotic pressure) and its enzymatic activity, e.g., lactate dehydrogenase (LDH) and ß-N-acetylglucosaminidase (ß-NAG) were determined. Moreover, for the first time, the percentage of live, dead, and apoptotic sperm, as well as the proteolytic activity of seminal plasma, were determined using flow cytometry and zymography, respectively, at specific times during the common carp reproductive period. The lowest volumes of semen and sperm concentration were noted during the first semen collection (June 1). Analysis of computer-assisted sperm analysis parameters revealed the greatest sperm motility, sperm velocity, as well as amplitude of lateral head displacement, were evident in the third collection (June 19). There were no differences in progressively motile sperm, movement linearity, wobbling index, and beat cross frequency between the different collection times. The lowest percentage of live sperm was found in the first collection, although with the passage of time values of this parameter increased. Seminal plasma pH and seminal plasma osmotic pressure were at the lowest values in the second collection (June 12), which corresponded with the lowest concentration of sperm. In the first collection, seminal plasma contained the highest values of LDH and ß-NAG activity, whereas there were no differences in the proteolytic activity of seminal plasma determined between the different collections of semen. The results presented here indicate that during the reproductive period, males of common carp produce a large amount of semen of moderate quality. Low sperm motility noted in the second collection might be explained by a significant increase in sperm production during this period, followed by a low seminal plasma pH and high hydration rate. The high LDH and ß-NAG activity noted in the first collection of semen may reflect a reduced stability of the sperm cell membrane and its viability. The significant difference in the percentage of live sperm at June 1 compared to that at June 19 supports this hypothesis.

Effects of birth weight and standardized litter size on growth performance of boars and subsequent reproductive performance

The aim of this study was to investigate the effects of birth weight and rearing litter size on growth and reproductive performance of boars. One hundred and forty male piglets were allotted to two groups, based on litter size: a smaller litter (SL) (8 piglets/litter, 70 boars) and a larger litter (LL) (12 piglets/litter, 70 boars). The boars in these litters were separated into two birth weight subgroups: lower birth weight (LBW) (mean: 1.15 kg, 70 boars) and greater birth weight (GBW) (mean: 1.59 kg, 70 boars). Testes volume, sexual activity and semen quality of boars at 180 days old were evaluated. The males in the GBW group, when compared with the LBW group, had greater bodyweight at 21, 28, and 63 days old ( P <0.01) and 180 days old ( P <0.05), greater testes volume and semen volume ( P <0.05), greater sperm concentration and total number of sperm in the semen ( P <0.01) and a longer ejaculation time ( P <0.05). The boars in the SL group had greater ( P <0.01) bodyweight at 21 and 28 days old, greater ( P <0.05) sperm concentration and total number of sperm in the semen than boars in the LL group. These results indicate that birth weight is a good predictor of sperm production in adult boars and suggest the possibility of increasing sperm production in adult boars by reducing the litter size in which they are reared. Keywords: Boars, bodyweight, piglets, reproduction, semen

Evaluation of the aphrodisiac potential of a chemically characterized aqueous extract of Tamarindus indica pulp

Ethnopharmacological relevanceTamarindus indica is an ingredient in the traditional aphrodisiac formulations in Africa and India. It is also a widely used food ingredient in other tropical countries. Aim of the studyThe present study was aimed to evaluate the aphrodisiac potential and reproductive safety profile of aqueous extract of Tamarindus indica in male Wistar rats. Materials and methodsThe aqueous extract was prepared by maceration of pulp followed by reduction of volume in rotavapor under heat followed by freeze drying. The prepared extract was characterized for contents of total phenol, flavonoid, and saponin. It was also subjected to phytoconstituent analysis using GCMS. Further, the extract was evaluated for acute toxicity study. The aphrodisiac and reproductive toxicity potential were evaluated in animals after grouping them in four with six animals each namely, normal control, standard (Sildenafil citrate, 4mg/kg p.o.) and extract of Tamarindus indica treated groups at two dose levels, 125 and 250mg/kg p.o. The study was conducted for 54 days with daily once dosing of extract and standard. Equal number of females was grouped without treatment for evaluation of parameters of sexual desire (mount frequency and intromission frequency) and parameters of sexual arousal (mount latency and intromission latency). These parameters were evaluated on day 14, 28, 42 and 54. Animals were sacrificed on day 54, testes were removed and studied for histopathological changes. ResultsThe extract showed 6.6mg gallic acid equivalent/g of total phenol, 2.3mg catechin equivalent/g of flavonoid and 11.6% saponin. Forty chemical constituents were identified by GCMS analysis. In acute toxicity study, the extract was found to be safe till 2000mg/kg p.o. Efficacy study showed significant (p<0.05) improvement in parameters of sexual desire (mount frequency and intromission frequency) and parameters of sexual arousal on all observed days except mount frequency for 125mg/kg on 42nd day and intromission frequency for both doses of tamarind compared to normal control. Improvements in these parameters were comparable to the standard drug. Histopathology study and sperm count suggested an increase in sperm production without any sign of toxicity in testis. Sperm motility significantly (p<0.05) increased in the treatment groups that received extract at 250mg/kg compared to normal control. ConclusionAqueous extract of Tamarindus indica possessed aphrodisiac activity together with spermatogenic potential.

Toward developing recombinant gonadotropin-based hormone therapies for increasing fertility in the flatfish Senegalese sole

Captive flatfishes, such as the Senegalese sole, typically produce very low volumes of sperm. This situation is particularly prevalent in the first generation (F1) of reared sole males, which limits the development of artificial fertilization methods and the implementation of selective breeding programs. In this study, we investigated whether combined treatments with homologous recombinant follicle-stimulating (rFsh) and luteinizing (rLh) hormones, produced in a mammalian host system, could stimulate spermatogenesis and enhance sperm production in Senegalese sole F1 males. In an initial autumn/winter experiment, weekly intramuscular injections with increasing doses of rFsh over 9 weeks resulted in the stimulation of gonad weight, androgen release, germ cell proliferation and entry into meiosis, and the expression of different spermatogenesis-related genes, whereas a subsequent single rLh injection potentiated spermatozoa differentiation. In a second late winter/spring trial corresponding to the sole’s natural prespawning and spawning periods, we tested the effect of repeated rLh injections on the amount and quality of sperm produced by males previously treated with rFsh for 4, 6, 8 or 10 weeks. These latter results showed that the combination of rFsh and rLh treatments could increase sperm production up to 7 times, and slightly improve the motility of the spermatozoa, although a high variability in the response was found. However, sustained administration of rFsh during spawning markedly diminished Leydig cell survival and the steroidogenic potential of the testis. These data suggest that in vivo application of rFsh and rLh is effective at stimulating spermatogenesis and sperm production in Senegalese sole F1 males, setting the basis for the future establishment of recombinant gonadotropin-based hormone therapies to ameliorate reproductive dysfunctions of this species.