Roles of antioxidants on prolonged storage of avian spermatozoa in vivo and in vitro

Effects of hydroxytyrosol on post-thaw quality of rooster sperm

Semen cryopreservation is one of the most important reproduction techniques in the livestock and poultry industry. Cryopreservation induces cold stress, generating reactive oxygen species (ROS) and oxidative stress causing structural and biochemical damages in sperm. In this study, we evaluated the effects of the hydroxytyrosol (HT), as an antioxidant, at the concentrations of 0, 25, 50, and 100 μg/mL on post-thaw semen quality metrics in rooster. Semen samples were collected twice a week from 10 roosters (29 weeks), processed and frozen according to experimental groups. Different quality parameters, including total motility, progressive motility, viability, morphology, membrane integrity, and malondialdehyde were measured after thawing. Results showed that 25 and 50 μg/mL of HT produced the highest percentage of total motility (51.01 ± 2.19 and 50.15 ± 2.19, respectively) and progressive motility (35.74 ± 1.34 and 35.15 ± 1.34, respectively), membrane integrity (48.00 ± 2.18 and 46.75 ± 2.18, respectively) as well as viability (53.00 ± 2.17 and 52.50 ± 2.17, respectively) compared with the other groups (p < .05). The group with 25 μg/mL of HT showed the lowest significant (p < .05) MDA concentration (1.81 ± 0.25). Our results showed that the effect of HT was not dose-dependent and optimum concentration of HT could improve functional parameters of rooster sperm after freezing-thawing. These findings suggest that HT may have protective effects on the rooster sperm during the freezing-thawing process.

Evaluation of the effect of the addition of an olive oil-derived antioxidant (Pectoliv-80A) in the extender for cryopreservation of rooster sperm through the use of a discriminant statistical tool

During the poultry sperm cryopreservation process, an excess of reactive oxygen species is generated resulting in oxidative stress which harms the quality of avian spermatozoa. To counteract this effect, the addition of exogenous antioxidants, such as Pectoliv-80A (a by-product of olive oil), to the cryopreservation diluent is interesting. For this purpose, 16 roosters belonging to the Utrerana avian breed were used. Six semen pools (from the 6 different replicates) were divided into 4 aliquots corresponding to different concentrations of Pectoliv-80A that were tested (0, 300, 400, and 500 μg/mL), and the cryopreservation process was carried out. To evaluate post-thawing semen quality, different parameters such as motility, membrane functionality, reactive oxygen species production, lipid peroxidation, and acrosome integrity were studied. A discriminant canonical analysis was used to determine both the differences between the Pectoliv-80A concentration groups and the discriminant power of the aforementioned parameter used for semen evaluation. Total motility and membrane functionality were reported to be the most discriminant variables for differentiating the different antioxidant enrichment groups and concluded that concentrations of 300 μg/mL showed the most desirable quality of post-thawing semen. The present study could lead to the optimization of both cryopreservation and quality evaluation techniques of the sperm of rooster species, that support the conservation program of endangered local breeds.

Fertility and Insemination Characteristics of Sperm Storage Tubules in Old Thai-Native Hens

We aimed to evaluate the effects of sperm concentration (150-250 × 106 spz/dose) and insemination frequency (once, twice, and thrice weekly) on fertility and sperm storage tubule (SST) characteristics. The SSTs were classified into five categories: namely, SSTs having an unscorable (SST1), empty (SST2), low (SST3), medium (SST4), and high (SST5) sperm count after insemination. The results showed that only insemination frequency affected the fertility rate (p < 0.05). The highest fertility was found in the thrice-weekly insemination group; however, this rate was not significantly different from that for the twice-weekly insemination group, except on day 7, while the once-weekly insemination group showed the lowest fertility rate (p < 0.05) from day four onward. On day 1, the SST characteristics showed no differences among the various insemination frequencies. On day 4, the SST2 and SST3 categories increased in the once-weekly insemination group (p < 0.05), while the SST4 and SST5 categories decreased compared to the twice- and thrice-weekly insemination groups (p < 0.05). On day 7, only the thrice-weekly insemination group maintained a level of SST5 category tubules like that measured on day 1 (p > 0.05). In summary, the insemination dose of 150 × 106 sperm was enough for fertilization, and thrice-weekly insemination was the appropriate frequency in old Thai native hens for maintaining a high sperm density in the SSTs throughout the week.

Improving the quality of chilled semen from Thai native chicken using phosphorus and vitamin B12 supplementation in semen extender

This study aimed to determine phosphorus and vitamin B12 supplementation effect in semen extender on the quality and fertility ability of chilled Thai native rooster semen. Eighty-four ejaculates of semen from 26 Thai native roosters (Burmese × Vietnam crossbreed) were included. Semen was collected by applying dorsal-abdominal massage once a week, pooled, diluted to 500 million sperms per dose, and divided into 6 groups. The semen samples used for control group were diluted with modified Beltsville poultry semen extender (BPSE). For the treatment groups 2 to 6: semen samples were diluted with modified BPSE and enriched with phosphorus and vitamin B12 (Octafos Octa Memorial Co., Ltd., Bangkok, Thailand) at concentrations 0.02, 0.04, 0.06, 0.08, and 0.10%. Semen fertility ability was tested in 6 replications by inseminating layer hens. Thirty-six Thai native hens were randomly assigned to 3 groups (control, 0.04, and 0.08%) of 12 hens and were inseminated with a dose of 0.2 mL on collecting day. Sperm motion characteristics (i.e., sperm motility, sperm progressive motility, and sperm kinetic parameters) were measured using a computer-assisted sperm analysis system (SCA, Proiser S.L., Valencia, Spain). Sperm viability, mitochondrial activity, acrosome integrity, plasma membrane integrity, and malondialdehyde (MDA) concentration were also evaluated. The sperm motion characteristics were the highest in the 0.04% supplementation group on all days of collection, especially the VCL and VAP (P < 0.05). The viability, mitochondrial activity, plasma membrane and acrosome integrity of spermatozoa were greater in the 0.04% supplementation group than in the control groups (P < 0.05). The 0.04% supplementation group had the lowest MDA concentration in all days of collection. The 0.04% supplementation group were higher both fertility (66.59 vs. 48.50%: P < 0.05) and hatching rates (58.80 vs. 43.18%: P < 0.05) than in the control group. In conclusion, 0.04% phosphorus and vitamin B12 concentrations supplementation in semen extender improved rooster semen quality and fertility in chilled rooster semen.

Germinated Wheat as a Potential Natural Source of Antioxidants to Improve Sperm Quality: A Canary Trial

The present study was carried out to determine the effects of germinated wheat on some spermatological parameters (motility, abnormal spermatozoa, hypo-osmotic swelling test (HOST), and viability) in male Gloster canaries. For this purpose, the canaries were divided into two groups, each consisting of six canaries, one control (C), and the other experimental group (GW). Group C was fed commercial canary feed. The GW group was fed germinated wheat (germinated for 5 days) and commercial canary feed. The canaries were kept individually in four-storey cages (60 cm × 50 cm × 40 cm). In this study, which lasted 2 months, feed/water was provided ad libitum and lighting was applied daily for 16 h (turned on at 05:30 and turned off at 21:30). At the end of the experiment, the sperm samples obtained from the canaries were examined in terms of the aforementioned parameters. The effects of germination time × concentration, germination time, and solvent rate on DPPH radical scavenging activity and phenolic compounds in germinated wheat were significant (p < 0.001). The highest DPPH (2, 2-diphenyl-1-picryl hydrazyl) radical scavenging activity (86.06%) and phenolic content (316.25 mg GAE/g) in germinated wheats were obtained on the fifth day (90% solvent rate) of germination. It was determined that germinated wheat did not significantly affect abnormal sperm and HOST values (p > 0.05). However, it significantly affected the motility and viable sperm rates (p < 0.05). As a result, it is thought that germinated wheat can be used as a natural antioxidant source to increase motility and vitality in canary sperm.

Improvement of diluted semen from Muscovy (Cairina moschata) drakes by the addition of water-soluble antioxidants

The aim of this study was to evaluate the effect of antioxidant supplementation in diluted semen from Muscovy drakes after the induction of oxidative stress (OS) on the sperm motility, kinematic parameters and biochemical markers - lipid peroxidation (LPO) levels and total glutathione (tGSH) concentration. The pooled semen was distributed equally into three parts, diluted (1:3 v/v) with IMV Canadyl, HIA-1 or AU, and stored at 4°C for 6 h. Later, the semen was equilibrated at 20-25°C for 15 min, and divided in Eppendorf tubes. The sperm samples (final concentration of 50 × 106 sperm cells/mL per sample) were incubated at 37°C for 30 min in the absence (-) or presence (+) of 0.1 mM FeSO4  + 0.5 mM H2 O2 (Fenton system) and the following combinations of antioxidants: ascorbic acid + Trolox (A + T); ascorbic acid + Desferal (A + D); Trolox + Desferal (T + D) and ascorbic acid + Trolox + Desferal (A + T + D), all of them in a final concentration of 0.1 mM. Thus, the total number of samples was 30 and in each one, the sperm motility, velocity parameters, LPO and tGSH were determined. The motility and kinematic parameters of the diluted semen with added antioxidants were restored by up to 20% after inducing OS via the Fenton reaction. Dual combinations of antioxidants (A + T, A + D, and T + D) lowered LPO levels, but not equally across different extenders. After the induction of OS, the tGSH levels in diluted semen with IMV-Canadyl were not affected by the added antioxidants. Whereas antioxidant combinations in diluted semen with HIA-1 or AU had a beneficial effect and partially restored tGSH levels. In conclusion, the results showed that the extender IMV-Canadyl is well balanced and protected the Muscovy semen under OS conditions, while the other two extenders HIA-1 and AU can be improved by adding antioxidants.

Reducing oxidative stress by κ-carrageenan and C60HyFn: The post-thaw quality and antioxidant status of Azari water buffalo bull semen

Azeri water buffalo is a species of great interest due to the high quality of its products such as milk. Due to the decreasing trend of its number and risk of extinction in the future, our attention is directed towards ensuring the preservation of its genetic reserves by keeping its sperm. Using antioxidants in semen extender is one of the ways to reduce the detrimental effects of freezing process on post-thawed quality of spermatozoa. This study was conducted to determine the effect of κ-carrageenan (k-CRG) and C60HyFn supplemented semen extender on the quality of post-thawed Azari water buffalo spermatozoa. A total of 30 semen samples were obtained from three buffaloes using an artificial vagina (twice a week for five weeks = 10 replicates). The samples (n = 3) from each replicate were pooled and divided into equal aliquots to prepare 14 extender groups, including control (C), k-0.2, K-0.4, K-0.6, K-0.8 (containing 0.2, 0.4, 0.8 mg K-CRG/mL, respectively), C-0.1, C-0.2, C-0.4, C-0.8, C-1, C-5, C-10, C-20, and C-40 (containing 0.1, 0.2, 0.4, 0.6, 0.8, 1, 5, 10, 20, 40 μM C60HyFn, respectively), and then frozen. After thawing, motility and velocity parameters, plasma membrane integrity (PMI) and functionality (PMF), DNA damage, Hypo-osmotic swelling (HOS) test, malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase glutathione activities and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were evaluated. In vivo fertility was compared between k-0.6, C-1 and control groups. 60 buffalo were inseminated 24 h after the onset of estrus. The diagnosis of pregnancy was performed rectally at least 60 days after fertilization. Total and progressive motility and velocity parameters were improved by k-0.4, k-0.6, k-0.8, C-0.4, C-0.8, C-1, C-5, and C-10 groups) compared to the other groups. Plasma membranes integrity and PMF were improved by k-0.4, k-0.6, C-0.4, C-0.8, C-1, C-5, and C-10 groups compared to other groups, while in terms of sperm DNA damage K-0.4, K-0.6, K-0.8, C-0.2, C-0.4, C-0.8, C-1, C-5, and C-10 groups showed better results compared to the control group. The evidence also showed that k- 0.4, k-0.6, k-0.8, C-0.4, C-0.8, C-1, C-5, and C-10 groups could improve TAC, and decrease MDA levels. Also, k-0.4, k-0.6, k-0.8, C-0.2, C-0.4, C-0.8, C-1, C-5, and C-10 groups could improve GPx, CAT, and GSH levels, but no significant difference was found regarding SOD compared to the other groups. DPPH scavengers were tested by K-0.6, K-0.8 and C-1, C-5, C-10, C-0.8, C-0.4 and C-0.2 groups and compared to other groups improved. The fertility rate [70% (14/20)] was higher in C-1 than other groups. To conclude that k-CRG and C60HyFn supplementation can increase the quality parameters of cryopreserved buffalo semen after thawing and that 1 M C60HyFn can increase in vivo fertility of buffalo semen.

Increased male-induced harm in response to female-limited selection: interactive effects between intra- and interlocus sexual conflict?

Interlocus sexual conflict (IRSC) occurs because of shared interactions that have opposite effects on male and female fitness. Typically, it is assumed that loci involved in IRSC have sex-limited expression and are thus not directly affected by selective pressures acting on the other sex. However, if loci involved in IRSC have pleiotropic effects in the other sex, intersexual selection can shape the evolutionary dynamics of conflict escalation and resolution, as well as the evolution of reproductive traits linked to IRSC loci, and vice versa. Here we used an artificial selection approach in Japanese quail (Coturnix japonica) to test if female-limited selection on reproductive investment affects the amount of harm caused by males during mating. We found that males originating from lines selected for high female reproductive investment caused more oxidative damage in the female reproductive tract than males originating from lines selected for low female reproductive investment. This male-induced damage was specific to the oviduct and not found in other female tissues, suggesting that it was ejaculate-mediated. Our results suggest that intersexual selection shapes the evolution of IRSC and that male-induced harm may contribute to the maintenance of variation in female reproductive investment.

Long-term sperm storage in eusocial Hymenoptera

In internally fertilizing species, sperm transfer is not always immediately followed by egg fertilization, and female sperm storage (FSS) may occur. FSS is a phenomenon in which females store sperm in a specialized organ for periods lasting from a few hours to several years, depending on the species. Eusocial hymenopterans (ants, social bees, and social wasps) hold the record for FSS duration. In these species, mating takes place during a single nuptial flight that occurs early in adult life for both sexes; they never mate again. Males die quickly after copulation but survive posthumously as sperm stored in their mates' spermathecae. Reproductive females, also known as queens, have a much longer life expectancy, up to 20 years in some species. Here, we review what is currently known about the molecular adaptations underlying the remarkable FSS capacities in eusocial hymenopterans. Because sperm quality is crucial to the reproductive success of both sexes, we also discuss the mechanisms involved in sperm storage and preservation in the male seminal vesicles prior to ejaculation. Finally, we propose future research directions that should broaden our understanding of this unique biological phenomenon.

Peroxiredoxin 1 transfer during mating protects eupyrene sperm against oxdative stress in Grapholita molesta

BACKGROUND

Each Grapholita molesta female only copulates once during its lifetime and thus must maintain the viability of stored eupyrene sperm for male reproductive success. The male ejaculate comprises abundant accessory gland proteins produced by the male accessory gland (AG), and many of which are major effectors for sperm storage and maintenance.

RESULTS

Here, we reported that an antioxidant protein, peroxiredoxin 1 (GmolPrx1), secreted by the male AG, is essential for protecting eupyrene sperm from oxidative stress and maintaining their quality during storage in the female bursa copulatrix (BC). Our data showed that GmolPrx1 is highly expressed in the AG of sexually mature males. The GmolPrx1 protein is localized to the cytoplasm of AG cells and delivered to the female BC during mating. Knockdown of GmolPrx1 strongly decreased the fertility of mated females. Additionally, we evaluated oxidative status in the spermatophore of females and found that the content of hydrogen peroxide increased significantly after mating with GmolPrx1 knockdown males. Finally, the quality assessment of eupyrene sperm demonstrated that the plasma membrane integrity, acrosome integrity, and DNA integrity were all severely impaired in the spermatophore of females after mating with GmolPrx1 knockdown males, which may contribute to the fertility decline in males.

CONCLUSION

Our current data demonstrated that activities of eupyrene sperm stored in females can be significantly impaired by enhanced oxidative stress through knocking down of GmolPrx1 in males. Our finding thus may further lay new foundations for the control of G. molesta through suppressing their populations by manipulating male reproductive genes. © 2023 Society of Chemical Industry.

Solid storage supplemented with serine of rooster semen enhances higher sperm quality and fertility potential during storage at 5 degrees Celsius for up to 120 hours

Information on prolonging the storage duration of cold semen with acceptable fertility in roosters is limited. This study aimed to determine the efficiency of solid storage with the addition of various concentrations of serine to the Thai native rooster (Pradu Hang Dum) semen extender on semen quality and fertility potential during storage at 5°C for up to 120 h. Pooled semen was diluted with a base extender and a gelatin extender containing 0, 2, 4, and 6 mM serine, then stored at 5°C for 120 h. In Experiment 1, the semen quality and malondialdehyde (MDA) concentrations were assessed at 0, 24, 72, and 120 h after storage. In Experiment 2, fertility potential in terms of fertility and hatchability rates was determined using the most effective solid-storage semen from Experiment 1. Sperm quality decreased with increasing storage time (P < 0.05). The lowest semen quality was observed in the control group since T24 of storage compared with the other groups (P < 0.05). Progressive motility, viability, and mitochondrial function were higher (P < 0.05) in the extender supplemented with gelatin and serine groups than those in the gelatin alone group at T72 and T120. In the extender supplemented with gelatin and serine groups, the highest semen quality was observed in the gelatin with 4 mM serine groups. The differences among extenders supplemented with serine were insignificant (P > 0.05), and the lowest MDA was observed in the gelatin with 4 mM serine groups. The fertility and hatchability rates in gelatin with 4 mM serine at T24 were comparable to those in fresh semen (83.87 and 86.12% vs. 86.66 and 88.3%; P > 0.05). Those of T72 were significantly better than those of the control at the same hour of storage (64.08 and 71.61% vs. 52.38 and 64.48%), while those of T120 were not different among groups. In summary, a semen extender as a solid medium supplemented with 4 mM serine successfully preserved the rooster semen for a long duration up to 72 h of storage time.

Sperm storage by females across the animal phyla: A survey on the occurrence and biomolecules involved in sperm storage

Long-term sperm storage by females in various regions of the oviduct is documented across many invertebrate and vertebrate species. Although, many reports emphasize on the histology, histochemistry and ultrastructural features of sperm storage, very little is known about the mechanisms underlying the sperm storage. The current review documents the occurrence of sperm storage by females in a wide array of invertebrate and vertebrate species. This review also provides an insight on the presence of various molecular factors of the sperm storage tubules presumably responsible for the prolonged sperm storage with an emphasis on a model reptile, the Indian garden lizard, Calotes versicolor which contains a unique approximately 55-kDa protein in its utero-vaginal lavage and found to inhibit washed epididymal sperm motility in a concentration and time-dependent manner in a reversible fashion.

New approaches for long-term conservation of rooster spermatozoa

In contrast to the livestock industry, sperm cryopreservation has not yet been successfully established in the poultry industry. This is because poultry sperm cells have a unique shape and membrane fluidity, differing from those of livestock sperm. The objective of this review is to discuss the cellular and molecular characteristics of rooster spermatozoa as a cause for their generally low freezability. Furthermore, here, we discuss novel developments in the field of semen extenders, cryoprotectants, and freezing processes, all with the purpose of increasing the potential of rooster sperm cryopreservation. Currently, it is very important to improve cryopreservation of rooster sperm on a global scale for the protection of gene resources due to the incidence of epidemics such as avian influenza.

Advances in storage of poultry semen

Semen cryopreservation is a key biotechnological strategy used to preserve and protect genetic resources, which are subject to increasingly serious reductions in some species, and to protect animal biodiversity. Assisted reproductive techniques, however, are still not utilized to the same extent in avian species to the extent that occurs in mammals. The reasons for this situation are described in this review. The content of this paper is focused on current poultry preservation systems, published since 2010, and new strategies that are very promising for preserving avian genetic resources. Two major types of storage technologies which are utilized for avian sperm preservation, liquid storage and cryopreservation, are emphasized. The issues on which there is a focus includes supplementation of avian extenders with various compounds prior to the preservation period, use of cryoprotectants and fertility results when there were in vitro sperm evaluations. Results from recent studies indicate there are opportunities to improve the quality of bird semen after preservation. It is obvious that cryo-diluent composition may be the most important factor for development of efficacious cryopreservation methods for avian semen.

Effects of Dietary Vitamin E Supplementation on Reproductive Performance, Egg Characteristics, Antioxidant Capacity, and Immune Status in Breeding Geese during the Late Laying Period

This study aimed to tentatively evaluate the effects of dietary vitamin E (VE) on goose reproductive physiology through the investigation of reproductive performance, egg characteristics, antioxidant capacity, and immune status in breeding geese. A total of 480 female and 96 male Jiangnan White breeding geese were randomly assigned to four treatments with four replicates, and each replicate had 30 females and six males. Four levels of VE were successively added to four treatment diets from 48 to 54 weeks of age, representing the effects of VE deficiency (0 IU/kg), basic-dose VE (40 IU/kg), middle-dose VE (200 IU/kg), and high-dose VE (2000 IU/kg). Neither the egg-laying rate nor the healthy-gosling rate were affected by any of the VE supplementations (p > 0.05). The qualified egg rate, hatchability of fertilized eggs, and spleen index were increased by each VE supplementation (p < 0.05). Egg fertility, the concentration of plasma reproductive hormones (i.e., the follicle-stimulating hormone, estradiol, and progesterone), follicular development, and antioxidant enzyme activities—i.e., the concentration of malondialdehyde (MDA), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)—in the liver and ovary were improved by 200 IU/kg of dietary VE (p < 0.05). Plasma VE concentration, immunoglobulin A, and immunoglobulin G content were increased, whereas plasma vitamin D3 concentration was reduced by increasing dietary VE levels to 2000 IU/kg (p < 0.05). The VE deposition of yolk, the yolk color depth, and the albumen rate were increased by each VE supplementation (p < 0.05). Antioxidant enzyme activities (i.e., MDA concentration, T-AOC, SOD, and GSH) in yolk were improved by 200 IU/kg and 2000 IU/kg of dietary VE (p < 0.05), compared with 0 IU/kg. The VE deposition was significantly correlated with GSH activity and the MDA concentration in egg yolk (p < 0.05). However, the high intake of dietary VE (2000 IU/kg vs. 200 IU/kg) decreased egg fertility (p < 0.05) and reduced the antioxidant capacity in the liver and ovary (p < 0.05). The qualified egg rate was positively correlated to immunoglobulin production (p < 0.05). Egg fertility and hatchability were correlatively improved by increased antioxidant enzyme activity; decreased MDA in the liver and ovary; hatchability; and enhanced immune status (p < 0.05). To sum up, both VE deficiency and high-dose VE (2000 IU/kg) reduced reproductive performance, whereas a dose of 200 IU/kg VE achieved optimal fertility, possibly through enhancing antioxidant capacity and immune status.

Spermatozoa Survival in Egg Yolk-Based and Soybean-Based Extenders at Ambient and Chilling Temperature in Domestic Turkeys (Meleagris gallopavo)

Populations of many galliform species have declined mainly due to habitat loss and over-hunting, notably the Congo peacock, which has been classified as a vulnerable species by the International Union for Conservation of Nature (IUCN). The domestic turkey, being a species of least concern, which has been reported to be closely related to peacocks, could serve as a model for the optimization of assisted reproductive technologies for the Congo peacock. This study was aimed at developing a suitable turkey semen extender for artificial insemination in field conditions. Semen was collected using the dorso-abdominal massage technique from seven turkey toms and analyzed. Ejaculates with >70% motility and >80% live spermatozoa were pooled and divided into four aliquots (four treatments). Each of the four treatments was extended in a soybean-based extender or an egg yolk-based extender, with or without L-ascorbic acid. Two liquid preservation protocols (ambient temperature (35 °C) and chilled (4 °C)) were employed, and quality parameters including motility, viability and morphology were evaluated. The results show that the two extenders were similar with regard to semen quality parameters, and L-ascorbic acid supplementation of the turkey semen extenders improved semen quality during liquid storage.

Effect of vitamin E supplementation on chicken sperm quality: A meta-analysis

Background and Aim:

Among several factors, the sperm quality of poultry is affected by the rooster’s body size and the availability of antioxidants like vitamin E. This study aimed to determine the effect of dietary vitamin E supplementation on rooster sperm quality through a meta-analysis.

Materials and Methods:

After verification and evaluation, a total of 19 articles were included in this study. Data, including dietary vitamin E, semen volume, concentration, total sperm cells, pH, motility, viability, percentage of dead and abnormal sperm, vitamin E sperm content, malondialdehyde (MDA) content, and testosterone levels, were tabulated in a database; these were subsequently analyzed using mixed modeling with vitamin E dose as a fixed effect and study identity as a random effect.

Results:

Dietary supplementation level of vitamin E significantly (p<0.001) affected sperm concentration, significantly affected motility (p<0.001), significantly affected sperm vitamin E (p<0.001), significantly affected viability (p<0.001), and significantly affected chicken sperm fertility (p=0.001). Vitamin E administration also significantly reduced the number of sperm cell deaths (p<0.001); however, increased dietary levels of vitamin E did not affect semen volume (p=0.853), pH (p=0.951), MDA (p=0.542), the percentage of abnormal sperm cells (p=0.343), nor testosterone levels (p=0.063).

Conclusion:

Dietary vitamin E supplementation is recommended for male chickens since it generally enhances the quality of their sperm.

Effect of prooxidants and chelator Desferal on the oxidative status and sperm motility of Muscovy semen

This study aimed to establish the sensitivity of Muscovy duck semen to oxidative stress (OS) and the effect of Desferal, applied as an antioxidant. The effect of three prooxidant systems in presence and absence of Desferal were tested on the motility and kinetic parameters (determined using CASA system), as well as the level of lipid peroxidation (LPO) and glutathione (tGSH) of Muscovy semen. The semen was diluted (1:3 v/v) with four extenders (saline solution, IMV Canadyl, HIA-1, and AU) and stored at 4 °C for 6 h. The cooled semen was divided into aliquots (50 × 106 sperm cells/mL), which were incubated at 37 °C for 30 min with one of the following prooxidative agents: ferrous sulfate (FeSO4, 0.1 mM), hydrogen peroxide (H2O2, 1 mM), and Fenton system (FeSO4(Fe2+), 0.1 mM + H2O2, 1 mM), in the presence or absence of Desferal (0.1 mM). The addition of FeSO4 + H2O2 or FeSO4 regardless of the used extender, as well as the addition of H2O2 to the diluted semen with saline solution significantly increased the levels of LPO (P < 0.05). With the lowest prooxidant effect was H2O2. The application of Desferal reduced significantly (P < 0.05) the LPO levels induced by FeSO4 + H2O2 or FeSO4 and in a weaker degree by H2O2. Among all prooxidants, FeSO4 + H2O2 decreased in the greatest extent the tGSH concentration in semen diluted with each used extenders in comparison to the relevant control. The addition of Desferal in semen diluted with HIA-1 extender and incubated with FeSO4, and H2O2, showed the best restoration of tGSH level, close to that of respectively controls. The studied prooxidants significantly reduced total, progressive, and kinetic sperm motility (P < 0.05). Although the inclusion of Desferal reduced the sperm OS, it did not improve the impaired by OS sperm motility.

The antioxidant roles of L-carnitine and N-acetyl cysteine against oxidative stress on human sperm functional parameters during vitrification

Objective

Amino acids can protect sperm structure in cryopreservation due to their antioxidant properties. Therefore, the present study aimed to investigate the protective effect of L-carnitine (LC) and N-acetyl cysteine (NAC) on motility parameters, plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), DNA damage, and human sperm intracellular reactive oxygen species (ROS) during vitrification.

Methods

Twenty normal human sperm samples were examined. Each sample was divided into six equal groups: LC (1 and 10 mM), NAC (5 and 10 mM), and cryopreserved and fresh control groups.

Results

The groups treated with LC and NAC showed favorable findings in terms of motility parameters, DNA damage, and MMP. Significantly higher levels of intracellular ROS were observed in all cryopreserved groups than in the fresh group (p≤0.05). The presence of LC and NAC at both concentrations caused an increase in PMI, MMP, and progressive motility parameters, as well as a significant reduction in intracellular ROS compared to the control group (p≤0.05). The concentrations of the amino acids did not show any significant effect.

Conclusion

LC and NAC are promising as potential additives in sperm cryopreservation.

Characterization of Oviduct Lining, with Emphasis on the Sperm Storage Tubule Region (Uterovaginal Junction), Correlated with Fertility in Mature and Old Thai Native Hens

The effect of age on fertility was investigated in Thai native chickens. The objective of this study was to determine the effects of age (mature and old) on the morphological characteristics of the reproductive organs and the histological characteristics of the uterovaginal junction (UVJ) tissues, resident sperm in the UVJ, and fertility duration in Thai native hens. We found no differences in the morphological characteristics of the reproductive organs, except for the number of follicles and the sizes of the fifth large yellow follicle in mature hens, which were greater than those in old hens (p < 0.05). The diameter of the sperm storage tubules (SSTs) epithelium was larger in old hens than in mature hens (p < 0.05), whereas the epithelium height was lower in old hens (p < 0.05). The number of sperm in the SSTs was greater in mature hens compared with old hens (p < 0.05). Mature hens showed a higher fertility rate than old hens. Our results suggest that, in old hens, the function of the SSTs is impaired, and sperm cannot be retained. Such a deterioration of the SSTs may be one of the factors involved in the decline in fertility.

Supplementation of Avian Semen Extenders with Antioxidants to Improve Semen Quality-Is It an Effective Strategy?

Oxidative stress in sperm is a phenomenon related to the increasing rate of oxidation of cellular components and the excessive production of reactive oxygen species (ROS). The high content of polyunsaturated fatty acids in bird sperm cell membranes renders these cells particularly susceptible to lipid peroxidation (LPO). Therefore, to ensure the proper functioning of cells, it is necessary to have a balance between the formation of ROS and the protective action of the antioxidant system. This review aims firstly to briefly introduce the antioxidant system characteristics of avian semen. Secondly, we summarize the recent knowledge regarding progress in extender supplementation using antioxidants and other compounds to improve avian semen quality parameters and fertility rates. The review focuses on enzymes, vitamins, amino acids, proteins, some plant extracts, and other compounds that can be used to supplement the extenders to reduce the formation of oxidants in poultry semen and maintain its quality and enhance its fertility.

From the Semen Collection Method to the Hatchlings: The Use of Cryopreserved Sperm from Pheasants Fed an Antioxidant-Enriched Diet

A widely used approach to preserving genetic diversity in birds involves the cryopreservation of semen. In this process, cells are subjected to physical and chemical stresses, but not all cell species respond equally. Many studies have been published on the freezing-thawing of sperm cells from a wide variety of domestic and wild species, on issues ranging from the sperm quality to different protocols, fertilisation success rates, etc. Nevertheless, very little information is available on the common pheasant. To fill this gap, the aim of this study was to describe the pheasant semen collection method, evaluate some qualitative parameters of sperm from males fed an antioxidant-enriched diet, and to test the in vivo fertilising capacity of the cryo-preserved semen. The freezing protocol employed involved pellets thawed by the hotplate method. Dimethylacetamide was used as a cryoprotectant at a final concentration of 6%. A total of six AIs were performed at 3-4-day intervals on a total of 40 females with doses of 35 × 106 of normal live thawed sperm. Males receiving the enriched diet produce more abundant and concentrated ejaculates. Freeze-thawed sperm lost 85% of their initial mobility, and diet influenced neither sperm mobility nor viability. The enriched diet did improve the number of normal freeze-thawed cells and was associated with a lower sperm fracture incidence. Regardless of the dietary group, frozen-thawed sperm resulted in a fertility rate of 30%, with 8-9 chicks hatching for every 100 eggs incubated.

The effects of varying concentrations of glutathione and trehalose in improving microscopic and oxidative stress parameters in Turkey semen during liquid storage at 5 °C

Since turkey reproduction is mainly through artificial insemination, short-term preservation of turkey semen is one of the most important issues in turkey reproduction management. The present study investigates the effects of glutathione (GSH) and trehalose on lipid peroxidation degree and turkey semen quality while being stored at 5 °C for 72 h. To this end, semen samples were collected from 20 turkeys with a weekly frequency for 12 weeks. A glucose-based extender was used to dilute the pooled semen. It was divided into seven equal parts with varying levels of glutathione [0.5, 1 and 2 mM), trehalose [50, 75 and 100] and control [extender without antioxidant]. Subsequently, the divided semen samples were stored at 5 °C for 72 h. Several sperm parameters such as motility and motion parameters, plasma membrane integrity (PMI), plasma membrane functionality, DNA integrity, and oxidative parameters were assessed following storage for 0, 24, 48, and 72 h. The obtained results indicated an improvement in the plasma membrane functionality and DNA integrity, along with the percentages of PMI in GSH-2 mM group in comparison to the control group following storage at 5 °C for 72 h (P ≤ 0.05). It is also notable that the 2 and 1 mM concentrations of GSH increased the spermatozoa motility and motion parameters in comparison to the control group, respectively (P ≤ 0.05). The study results indicated that GSH-2, 1 mM and trehalose- 100 mM concentrations reduced lipid peroxidase levels and increased total antioxidant activity, catalase, superoxide dismutase, and glutathione peroxidase in comparison to the control group (P ≤ 0.05). Our study's data show that improvement of semen parameters and oxidative stress parameters of turkey semen can be improved by glutathione at 2 and 1 mM and trehalose at 75 mM while storing it 5 °C.

Physiological factors influencing female fertility in birds

Fertility is fundamental to reproductive success, but not all copulation attempts result in a fertilized embryo. Fertilization failure is especially costly for females, but we still lack a clear understanding of the causes of variation in female fertility across taxa. Birds make a useful model system for fertility research, partly because their large eggs are easily studied outside of the female's body, but also because of the wealth of data available on the reproductive productivity of commercial birds. Here, we review the factors contributing to female infertility in birds, providing evidence that female fertility traits are understudied relative to male fertility traits, and that avian fertility research has been dominated by studies focused on Galliformes and captive (relative to wild) populations. We then discuss the key stages of the female reproductive cycle where fertility may be compromised, and make recommendations for future research. We particularly emphasize that studies must differentiate between infertility and embryo mortality as causes of hatching failure, and that non-breeding individuals should be monitored more routinely where possible. This review lays the groundwork for developing a clearer understanding of the causes of female infertility, with important consequences for multiple fields including reproductive science, conservation and commercial breeding.

Lipid profile of sperm cells in Thai native and commercial roosters and its impact on cryopreserved semen quality

Plasma membrane lipids are the key factor in the ability of chicken sperm to be frozen. They ensure fluidity and flexibility of the sperm membrane for effective viability and motility during in vitro storage. The objective of this study was to compare the lipid profiles of different native and commercial chicken breeds: native Thai (Pradu Hang Dam) roosters and commercial (Rhode Island Red) roosters, with respect to their frozen sperm quality. In addition, lipid peroxidation and antioxidant enzymes superoxidase dismutase (SOD) and catalase (CAT) were also examined. Semen was collected from 12 roosters of each breed. For fresh semen, parameters assessed include semen volume, pH, sperm concentration, sperm motility, and viability, while for frozen semen, the parameters assessed were sperm motility and viability. Moreover, other parameters assessed included malondialdehyde (MDA) concentration, activities of SOD and CAT, and fatty acid profile. We found that sperm viability and motility of frozen semen were higher in the commercial breed than in the native breed (P < 0.05). The commercial chicken breed had higher MDA concentration than the native breed (P < 0.05), but antioxidant enzymes remained unchanged in both. Levels of arachidonic acid (AA; C20:4n-6) and docosahexaenoic acid (DHA; C22:6n-3) were significantly higher (P < 0.05) in the commercial than in the native breed; however, n-6 to n-3 ratios were not different. In conclusion, our study found that lipid profiles have an influence on frozen sperm viability and motility between the breeds. Polyunsaturated fatty acids, particularly AA and DHA, are beneficial to sperm quality.

Growth performance and fertility of Windsnyer boars supplemented with α-tocopherol

The purpose of the present work was to determine the response in growth performance and spermatozoa characteristics of Windsnyer boars supplemented with progressive levels of α-tocopherol. Twenty Windsnyer boars aged 12 weeks with an average body weight of 19.5 ± 2.67 kg were used. Each boar was housed individually in a 1.54 × 0.8 m pen in environmentally controlled house with the temperature ranging from 22 to 25 °C. Five boars were randomly assigned to each diet containing 0, 40, 70 and 90 IU of α-tocopherol. The growth performance experiment lasted for 12 weeks. Subsequently, boars were humanely slaughtered for analyses of testicular development and spermatozoa characteristics. Polynomial regression was used to analyse data. There was a linear response (P < 0.05) in average daily gain and feed conversion ratio as α-tocopherol levels increased. Left and right testicular weights showed a linear increase (P < 0.05) with increasing levels of α-tocopherol. Weights of left and right epididymis exhibited quadratic response (P < 0.05). Seminiferous tube area responded in a quadratic fashion (P < 0.05). There was a quadratic relationship (P < 0.05) between semen volume, straight-line velocity and live spermatozoa. Dead spermatozoa and head abnormalities exhibited linear decrease (P < 0.05). In conclusion, inclusion of α-tocopherol improved growth performance and fertility of Windsnyer boars.

Effect of organic selenium dietary supplementation on quality and fertility of cryopreserved chicken sperm

Oxidative stress due to cryopreservation has been considered as a major factor in sperm damage. Supplementation of the diet with different concentrations of organic selenium has been proposed to improve the quality of fresh and frozen-thawed semen in different breeds of roosters. Sixteen Pradu Hang Dum (Thai native) and 16 Rhode Island Red roosters were used in this study. Four levels of selenium supplementation between 0 and 0.9 ppm were examined. After 14 days of feeding, semen samples were collected twice a week and the fresh semen was evaluated. Then semen from each group was pooled and cryopreserved. The fertility of frozen-thawed semen was determined by inseminating 48 layer hens. Supplementation of diets with 0.3, 0.6 and 0.9 ppm selenium improved the fresh semen in terms of sperm viability and normal morphology (P < 0.01). Sperm concentration increased (quadratically, P < 0.001) with increasing dietary selenium levels. Meanwhile, post-thawed semen quality in terms of sperm motility, viability, live with intact acrosome and functioning mitochondria improved significantly with selenium treatments of 0.6 and 0.9 ppm, and lipid peroxidation was decreased (P < 0.001) and fertility improved (P < 0.05) with those levels of selenium treatment. In addition, there were differences between breeds with respect to some fresh or frozen semen quality parameters (P < 0.05). In conclusion, the breed affected both fresh and frozen semen. Even there were no statistically significant differences in the parameters from groups 0.6 and 0.9 ppm on frozen-thawed semen quality, but the highest sperm concentration was found in 0.6 ppm. Therefore selenium supplementation of diets at 0.6 ppm was recommended to improve the quantity and quality of fresh and frozen semen.

Effects of dietary alpha-lipoic acid supplementation on the seminal parameters and fertility potential in aging broiler breeder roosters

High levels of polyunsaturated fatty acids in avian sperm cause more susceptibility to lipid peroxidation. Aging in roosters reduces the antioxidant capacity of sperm and thus fertility. The purpose of this study was to investigate the effects of different levels of alpha-lipoic acid (ALA) as a feed supplement to improve the semen quality and fertility parameters of aged broiler breeder roosters and identification of its most effective level. A total of forty-two roosters at 45 wk of age were randomly assigned to 7 treatments (0, 15, 40, 70, 95, 120, and 145 mg ALA/bird per day) for 8 wk. Semen parameters and body weight were assessed biweekly, and testosterone plasma levels were determined in the 8th wk of the experimental period. Artificial insemination was performed at the end of the experiment to evaluate the fertility potential. The dietary administration of ALA had no significant effects on body weight, semen volume, average path velocity, linearity, straightness, wobble, the amplitude of lateral head displacement, beat-cross frequency, sperm concentration, morphology, plasma testosterone level, fertility, or hatchability (P > 0.05). Alpha-lipoic acid supplementations resulted in a significant decrease in seminal malondialdehyde concentration and immotile (type D) sperms (P < 0.05). The total motility, progressive motility (types A + type B sperms), curvilinear velocity, straight-line velocity, viability, and membrane integrity of sperm improved with ALA dietary supplementations (P < 0.05). With increasing ALA levels, improvement in semen parameters had an incremental trend until the level of 95 mg ALA. Thus, 95 mg dietary ALA as an antioxidant supplement can improve semen quality of aging breeder roosters while higher doses resulted in no further improvement.

Sexual dimorphism and sex-biased gene expression in an egg parasitoid species, Anastatus disparis

Background

Differences in the expression of genes present in both sexes are assumed to contribute to sex differences including behavioural, physiological and morphological dimorphisms. For enriching our knowledge of gender differences in an important egg parasitoid wasp, Anastatus disparis (Hymenoptera: Eupelmidae), sex-biased differences in gene expression were investigated using Illumina-based transcriptomic analysis.

Results

A total of 15,812 resulting unigenes were annotated, and a large set of genes accounting for 50.09% of the total showed sex-biased expression and included 630 sex-specific genes. Gene Ontology (GO) enrichment analyses showed that the functional categories associated with sex-biased genes were mainly related to reproduction. In addition, the transcriptome data provided evidence that sex pheromones in A. disparis are produced by the female, and activity of Δ12-desaturases appear to have been replaced by Δ9-desaturases playing roles in sex pheromone production. The large set of sex-biased genes identified in this study provide a molecular background for sexually dimorphic traits such as flyability, longevity, and aggression in this species and suggests candidate venom proteins expressed only in females that could be used for biological control.

Conclusions

This study provides comprehensive insight into sexually dimorphic traits of a parasitoid wasp and can inform future research into the molecular mechanisms underlying such traits and the application of parasitoids to the biological control of pest species.

Effects of k-carrageenan supplementation or in combination with cholesterol-loaded cyclodextrin following freezing-thawing process of rooster spermatozoa

This experimental research purposely seeks to explore the effect of supplementing k-carrageenan (k-CRG) or CLC (cholesterol-loaded cyclodextrins) or the combined effect of k-CRG and CLC as supplements of antioxidants to an extender for rooster semen freezing. A total of 75 neat pooled ejaculates were collected twice a week from twenty-five (25) commercial line arbor acres broiler roosters (30 wks) during the experimental period. In each replicate, semen samples (n= 15, three ejaculates per rooster) were pooled and divided into nine equal aliquots, and each aliquot was diluted with one of the following extender supplemented with k-CRG, CLC, and k-CRG + CLC after which it was subjected to cryopreservation process using the "pellet" method. In study I, the supplementation of extenders with k-CRG was in five equal aliquots as follows; (0.2, 0.4, 0.6, 0.8) mg/mL and control group (k-CRG 0) mg/mL while in Study II, there was a combination of both k-CRG + CLC (0.4 mg/mL + 1.5 mg/mL, respectively), 0.4 mg/mL k-CRG, 1.5 mg/mL CLC and control group. Sperm quality parameters, endogenous antioxidant enzymes, lipid peroxidation (MDA) and ROS were all assessed after the freeze-thaw process. Our findings in study I indicated that at post-thaw, an optimum 0.4 mg/mL k-CRG supplementation in the extender improved semen quality parameters, endogenous enzymes, MDA and ROS in comparison to the control group. Interestingly prior to the freeze-thaw process, it was depicted in study II that combined k-CRG + CLC (0.4 mg/mL+1.5 mg/mL) inclusion in the extender provided maximum protection to sperm quality parameters, endogenous enzymes, MDA and ROS in comparison to 1.5 mg/mL CLC and control group at post-thaw. Besides, there was also a significant difference observed in the extenders supplemented with combined k-CRG + CLC (0.4 mg/mL +1.5 mg/mL) when compared to 0.4 mg/mL k-CRG for semen quality parameters and endogenous antioxidant enzymes (SOD, CAT, and GPx) but no significant difference was observed for MDA and ROS. Also, there was a significant difference observed in the extender supplemented with 1.5 mg/mL CLC when compared to the control group for semen quality parameters, SOD, CAT, and MDA but no significant difference for GPx and ROS at post-thaw. In conclusion, k-CRG at an optimal dosage of 0.4 mg/mL proved effective for improving post-thaw sperm quality but its combined addition k-CRG + CLC at an optimal concentration of (0.4 + 1.5) mg/mL in the extender provided greater protection to the rooster spermatozoa at post-thaw.

Comparative effects of nano-selenium and sodium selenite supplementations on fertility in aged broiler breeder males

It is well documented that aging has negative effects on fertility. With increasing age, the activity of antioxidant enzymes are reduced and because of roosters sperm composition, a high proportion of polyunsaturated fatty acids (PUFAs), the probability of sperm damage increases. The objective of the present study was to compare the effects of nano-selenium and sodium selenite on fertility in aged male broiler breeder chickens. Thirty-five male broiler breeders (Cobb 500)® at 50 weeks of age were randomly divided into five equal groups: The control group was fed on a commercial diet, group T1 was fed on a commercial diet supplemented with sodium selenite (0.30 mg kg-1 feed), group T2, T3 and T4 were fed on a commercial diet supplemented with nano-selenium (0.15, 0.30 and 0.60 mg kg-1 feed, respectively). Sperm characteristics (sperm count, motility, viability, and maturity) as well as testicular histomorphometric features [tubule differentiation (TDI), spermiation (SPI), Sertoli cell (SCI) and meiotic (MI) indices] were assessed. The results showed that sperm characteristics were gradually decreased with age in the control group, however, it increased in group T3. Also, TDI, SPI, SCI, and MI in group T3 were higher than those of other groups. Our findings revealed that dietary supplementations with nano-selenium boosted fertility in aged male broiler breeders and the best results were obtained when the roosters received 0.30 mg kg-1 nano-selenium. Supplementation of nano-selenium in aged broiler breeder males might be effective to maintain flock fertility and/or increase the flock fertility.

Detrimental effects of excessive fatty acid secretion on female sperm storage in chickens

Background

Female sperm storage (FSS), the maintenance of sperm inside the female reproductive tract for an extended period of time, is pervasive among organisms with internal fertilization. Because FSS enables asynchronous mating and fertilization, it could be extremely important to reproduction. However, the physiological mechanisms underlying prolonged preservation and maintenance are poorly understood. Here, we used chicken, a typical oviparous animal, to determine the mechanisms ensuring sperm functionality in sperm storage tubules (SSTs).

Results

We performed an insemination experiment on over two thousand hens at two periods, and found that the FSS capabilities varied widely among individuals. Except for the differences in the SST density between the two groups with distinct FSS abilities, we quantitatively profiled small-molecule metabolites derived from SST cells, and identified 28 metabolites with differential expression. In particular, high levels of lipids, fatty acids and lipid peroxidation product were observed in hens with low FSS capability. Pathway analysis showed that these differential metabolites were significantly enriched in the biosynthesis of unsaturated fatty acids. Moreover, we detected the total antioxidant capacity and lipid peroxidation level of SSTs, and found that chickens with a lower FSS ability had a significantly higher content of lipid peroxidation end-product, which was 2.4-fold greater than chickens with a higher FSS capability, and no significant difference was found in the total antioxidant capacity between these two groups.

Conclusions

Our findings reveal that the long-term storage of sperm and the maintenance of their function in the female reproductive tract require an adequate microenvironment. The superabundance of fatty acids secreted by SST cells had detrimental effects on sperm storage in the female reproductive tract. Lipid peroxidation produces toxic biological substances that may cause irreversible damage to resident spermatozoa, resulting in short-term sperm retention and decreased fertility. Our findings provide new avenues for studying sperm storage and sustaining fertility.

Avian uterine fluid proteome: Exosomes and biological processes potentially involved in sperm survival

Uterine fluid is an aqueous milieu to which sperm are exposed during their storage and ascent. In this study, a bottom-up proteomic strategy and bioinformatic analysis of hen uterine fluid was performed to improve the understanding of this fluid and its potential role in sperm survival mechanisms. The proteomic data were submitted to ProteomeXchange. Among the 913 proteins identified, 160 are known to be secreted and 640 are referenced in exosomes databases. We isolated exosomes from the avian uterine fluid, analyzed them using electron microscopy, and targeted several exosomes markers (ANXA1/2/4/5, VCP, HSP90A, HSPA8, PARK7, and MDH1) using immunoblotting. Electron microscopy and immunohistochemistry were also used to analyze uterovaginal junctions for the exosomal proteins ANXA4, VCP, and PARK7. Exosomes were observed both at the surface epithelium and inside sperm storage tubules. Our data were compared with two previously published studies on proteomic of hen uterine fluid, and with one study describing the proteomic content of rooster seminal plasma and sperm. In conclusion, we demonstrated for the first time that avian uterine fluid contains exosomes. These may play a key role in preserving sperm functions within the female genital tract. Their presence in the sperm storage tubules may represent an important mechanism regarding interaction between the female genital tract and sperm.

Comparison of TNC and standard extender on post-thaw quality and in vivo fertility of Thai native chicken sperm

Semen extender has a vital role in preservation of sperm cells properties in terms of sperm viability, motility, acrosome integrity, and mitochondrial membrane potential. The objective of the present study was to evaluate a new extender, known as Thai native chicken (TNC) extender compared to BHSV-based and modified Sasaki extenders for freezing chicken semen. Semen from Thai native roosters was collected, pooled, and randomly divided into three groups. Semen was frozen with a simple freezing method using nitrogen vapor and dimethylformamide. In the first experiment, post-thaw motion parameters, viability, acrosome integrity, mitochondrial function, and lipid peroxidation levels were analyzed using computer-assisted sperm analysis, propidium iodide, fluorescein isothiocyanate-conjugate peanut agglutinin, JC-1, and the thiobarbituric acid reaction. Results showed that the type of extender had no effect on the percentage of total motile and curvilinear velocity. The percentage of progressive motile, straight-line velocity, and average path velocity of post-thawed semen were significantly lower in TNC compared to the modified Sasaki extender. However, the percentages of post-thawed acrosome integrity and active mitochondria were significantly higher in TNC extender (P < 0.05). For the second experiment, semen was thawed by using each of extenders thereafter, was inseminated to 48-layer breeder hens to determine the fertility rate. Among the three extenders used, the highest fertility rate was found in TNC extender. In conclusion, TNC extender can be recommended as an appropriate and useful cryopreservation media for native chicken semen since it maintains the quality of rooster semen and fertility after freezing and thawing process.

Beneficial effects of dietary coenzyme Q10 on the productive and reproductive variables of broiler breeder hens

The aim of this study was to evaluate the effects of supplementary CoQ10 in the diets of aged broiler breeder hens on productive and reproductive variables. A total of 128 hens)44 weeks of age) were randomly assigned to one of 16 groups (eight hens per group). The hen-groups (with equal mean egg production and egg weight) were randomly assigned to one of four diet-groups to provide four pen/groups per treatment. There was no CoQ10 supplementation or supplemental amounts of either 300, 600 or 900 mg CoQ10/kg added to the basal diet. Egg production, weight, and mass were determined weekly. To assess fertility, hatchability, and sperm penetration (SP) rate, the hens were artificially inseminated on a weekly basis (from 47-54 weeks of age). The hens were weighed and killed at the end of the experiment for evaluation of the ovarian morphology, oviduct histology, utero-vaginal junction (UVJ) total antioxidant capacity (TAC), and Pdss2, GDF9, and BMP15 mRNA transcript abundances in the germinal disc regions. The results indicated that there was a linear response curve to increasing amounts of supplemental dietary CoQ10 on fertility, hatchability of eggs, SP rates, TAC of the UVJ, fold height and surface epithelia of the magnum and isthmus, and abundance of GDF9, BMP15 and Pdss2 mRNA transcripts in the germinal disc region. In conclusion, the findings of the present study indicate diet supplementation with CoQ10 had beneficial effects on the productive and reproductive variables of aged hens.

Different concentrations of cysteamine, ergothioneine, and serine modulate quality and fertilizing ability of cryopreserved chicken sperm

The aim of this study was to evaluate the effects of freezing diluents supplemented in three potential amines/amino acids, namely, antioxidant cysteamine (2-aminoethanethiol [AET]), ergothioneine (ERG), and serine (SER), in optimization of chicken sperm cryopreservation. The semen of 36 Pradu Hang Dum males, selected based on their motility vigor score, was frozen by a simple freezing method using nitrogen vapors and dimethylformamide (DMF). In a first experiment, a wide range of AET, ERG, and SER doses were tested. Semen quality was evaluated after incubation at 5°C or after cryopreservation in straws in the Blumberger Hahnen Sperma Verdünner (BHSV) diluent + DMF (6% v/v) with or without AET, ERG, or SER. The best targeted doses of AET, ERG, or SER were then selected for experiment 2 that was focused on cryopreserved semen. Frozen-thawed sperm quality was evaluated by different in vitro tests and by evaluation of fertility. Objective motility parameters were evaluated by computer-assisted sperm analysis. Membrane integrity, acrosome integrity, and mitochondria function were evaluated using appropriate dyes and flow cytometry. Lipid peroxide production was assessed by the thiobarbituric acid test (malondialdehyde production). Fertility obtained with frozen-thawed semen supplemented or not in AET, ERG, or SER was evaluated after artificial insemination of laying hens. ERG and AET decreased sperm lipid peroxidation and decreased fertility, even at low doses. The presence of 4 mmol of SER significantly decreased lipid peroxidation, increased the frozen-thawed sperm quality, and increased fertility after sperm cryopreservation (90% vs. control 84%, P < 0.05). In a third experiment, the use of 1 mmol of sucrose (the best result of our previous study) added to 4 mmol of SER-supplemented extender was tested. This addition allowed to the highest levels of fertility (93%). In conclusion, the addition of 4 mmol of SER in semen cryopreservation diluents decreases peroxidation and improves the efficiency of the process.

Sperm characteristics of Chukar partridge (Alectoris chukar) breeders as affected by the addition of calcitriol to the semen extender

This study was carried out to determine the effect of supplementing the semen extender with calcitriol on in vitro sperm characteristics in Chukar partridges. A total of 60 male Chukar partridges were habituated for semen collection by abdominal massage. Pooled ejaculates from several males were extended (1 to 5 v/v ratio) in the Sexton's diluent containing 0, 24, 48, 96, or 192 μg calcitriol/mL. These concentrations represented 0-, 2-, 4-, 8-, and 16-fold levels of the mean seminal calcitriol concentration, respectively. A total of 12 subsamples from each treatment group were kept at 4 to 5°C or 19 to 24°C for 4, 24, or 48 h. The percentages of motile sperm, live sperm, abnormal sperm, incidence of hypoosmotic swelling (HOS), and thiobarbituric acid reactive species (TBARS) concentrations were determined. The data were analyzed by the xtmixed procedure of STATA software. The percentages of motile sperm, live sperm, abnormal sperm, and seminal TBARS were affected by calcitriol (P < 0.05). There was no effect of treatments on HOS (P > 0.05). There was an interaction effect between calcitriol, storage time, and storage temperature on sperm motility, sperm viability, and seminal TBARS. Supplementation of the diluent with 96 μg calcitriol/mL resulted in the highest sperm motility at 4°C. Also, the same treatment group recorded the highest sperm viability and lowest seminal TBARS at 19 to 24°C. Supplementing the diluent with calcitriol had beneficial effects on spermatozoa; however, the fertility rate of spermatozoa extended in calcitriol-supplemented diluent needs to be determined before the procedure can be recommended for use in artificial insemination programs.

Effect of supplementing vitamin E analogues on post-thaw semen parameters and fertility in chicken

1. The effect of supplementing water-soluble vitamin E analogues 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (trolox) and butylated hydroxy toluene (BHT) was studied in two separate experiments.2. In the first experiment, trolox was supplemented at 0.2 mM, 0.4 mM and 0.8 mM concentrations along with N-methylacetamide (MA; 12% final concentration) and semen was cryopreserved in 0.5 ml French straws. Different semen parameters and fertility were assessed from post-thaw samples.3. Sperm motility, live sperm, and mitochondrial activity were significantly lower (P < 0.05) in cryopreserved semen. Lipid peroxidation (LPO) was significantly higher (P < 0.05) in cryopreserved semen that was reduced by trolox supplementation. The treatment containing trolox at 0.2 mM concentration produced significantly higher (P < 0.05) fertility compared to unsupplemented cryopreservation treatment.4. In the second experiment, BHT was supplemented at 0.25 mM, 0.5 mM, and 1 mM concentrations along with MA during semen cryopreservation.5. Sperm motility, live sperm and MTT dye reduction test were significantly lower (P < 0.05) in cryopreserved semen. These parameters declined with increasing BHT concentration. Abnormal sperm was significantly higher (P < 0.05) in the BHT supplemented treatments. The sperm chromatin dispersion (SCD) test was significantly higher (P < 0.05) in cryopreserved samples and was highest in samples supplemented with 0.5 mM and 1 mM BHT. The percentage fertility was significantly lower (P < 0.05) in cryopreserved semen and BHT supplementation did not improve fertility.6. In conclusion, trolox supplementation at 0.2 mM concentration during semen cryopreservation improved fertility, whereas BHT supplementation resulted in a decline in post-thaw semen parameters.

Mitochondrial membrane potential and reactive oxygen species in liquid stored and cryopreserved turkey (Meleagris gallopavo) spermatozoa

The extensive use of artificial insemination in turkeys has led to the development of in vitro semen storage. However, fertility rates from liquid stored and frozen/thawed turkey semen are still unsatisfactory. The aim of the study was to assess spermatozoa viability, mitochondrial membrane potential (MMP), and reactive oxygen species production (ROS) in liquid stored and cryopreserved turkey semen with the use of flow cytometry. Moreover, motility and adenosine triphosphate (ATP) content in sperm were monitored at the same time to link flow cytometry data with sperm movement and energetics. Liquid storage led to a decrease in sperm motility (80.6 vs. 55.6%, for fresh and stored for 48 h), live sperm with an intact MMP (59.9 vs. 30.5% for fresh and stored for 48 h), and a 20-fold decrease in ATP content after 24 h of storage. A 3-fold increase in ROS+ sperm was observed after 48 h of storage (9.3 vs. 26.8% for fresh and stored for 48 h). Semen equilibration before cryopreservation affected only ATP content. However, freezing/thawing led to a dramatic decrease in all of the studied semen quality parameters. A 5-fold decrease in live sperm with intact MMP (59.8 vs. 11.9%) and a 7-fold increase in sperm ROS+ (10.8 vs. 74.4%) were recorded between fresh and frozen/thawed semen. The results strongly suggested that a significant loss of MMP and a disturbance in sperm ATP production during semen storage can be the main reason for the decline in sperm motility. The disturbance of mitochondria activity during storage seems to be associated with the increase in oxidative stress in turkey semen. Turkey sperm mitochondria also appear to be very sensitive to cryodamage. Diminished energy production in turkey spermatozoa, visible as the low percentage of sperm with an intact MMP and low level of ATP after freezing/thawing, which is associated with high ROS generation, could be responsible for the low fertilizing ability of cryopreserved turkey semen.

Sperm quality characteristics and fertilization capacity after cryopreservation of rooster semen in extender exposed to a magnetic field

There has not been as much success in the effectiveness of avian semen cryopreservation as that of mammalian semen cryopreservation. This has been attributed to the unique characteristics of poultry sperm. In the area of mammalian semen, the use of magnetized extenders has enhanced the cryo-resistance of sperm in some species. The applicability of this strategy to avian semen has not yet been evaluated. The purpose of this study was to evaluate the effects on sperm quality and fertility after magnetization of extenders and use of these extenders for cryopreservation of rooster semen. Extenders were passed between two neodymium magnets that produced different magnetic induction values (0, 2000, 4000 and 6000 G). Physicochemical properties of the extenders were assessed and then semen samples were cryopreserved in the magnetized extenders. The smallest cluster sizes and zeta potentials in the extenders were observed in the extender magnetized at 2000 gauss (G). There were greater percentages of sperm total motility, viability and mitochondrial membrane potential in semen treated with the extender magnetized at 2000 G A greater percentage of sperm with enhanced membrane functionality was observed when sperm were stored in extenders magnetized with 2000 G and 4000 G. In a field trial, there were greater percentages of fertility and hatching rates of eggs using semen treated with extenders magnetized at 2000 G and 4000 G. Cryopreservation of rooster semen with magnetized extenders at 2000-4000 G resulted in enhanced quality indices of thawed sperm as well as the fertility capacity of the cryopreserved semen.

Effect of the essential oil of Rosmarinus officinalis (L.) on rooster sperm motility during 4°C short-term storage

AIM

This study aimed to investigate the protective effect of Rosmarinus officinalis (L.) essential oil on rooster sperm motility during 4°C short-term storage.

MATERIALS AND METHODS

R. officinalis essential oil was analyzed using gas chromatography coupled to mass spectrometry to identify the active components. 10 of 45-week-old Hubbard commercial broilers were subjected to biweekly semen collections during 3 weeks. At each collection, sperm was pooled and divided into four aliquots and then diluted with Tris extender supplemented with 870, 87, or 8.7 µg/ml of R. officinalis essential oil, identified as treatments R, R5, and R10, respectively. Tris-based extender without any supplementation was considered as a control group. Diluted sperm was then stored at 4°C in the refrigerator and analyzed at 0, 6, 24, and 48 h using a computer-assisted sperm analyzer. Different semen parameters were measured including total motility, progressive motility, gametes velocities (straight line velocity [VSL], curvilinear velocity [VCL], and average path velocity [VAP]), amplitude of the lateral head displacement [ALH], and beat-cross frequency [BCF].

RESULTS

The phytochemical analysis of R. officinalis essential oil revealed the presence of 25 active components including seven major molecules: Camphor (18.88%), camphene (5.17%), 1,8-cineole (7.85%), β-thujene (13.66%), α-thujene (4.87%), chrysanthenone (12.05%), and β-cubenene (7.97%). The results showed a beneficial effect of R. officinalis essential oil on sperm cells motility, particularly when using the lowest concentrations, 8.7 and 87 µg/ml. Progressive motility and gametes velocities (VCL, VSL, and VAP), materializing the quality of gametes motility, showed highly statistically significant values (p<0.01) in 8.7 and 87 µg/ml treatments, especially from 6 h of storage at 4°C. Conversely, the highest concentration (870 µg/ml) showed harmful effects with a total spermicidal activity after 24 h of storage.

CONCLUSION

The current results revealed the positive impact of R. officinalis essential oil on rooster sperm at 4°C short-term storage probably through fighting against oxidative stress and cold shock damages.

Cryopreservation effects on sperm function and fertility in two threatened crane species

The capacity to cryopreserve semen from captive cranes facilitates production of offspring from behaviorally incompatible or geographically separated pairs, and allows for long-term preservation of valuable genetic materials. The present study sought to develop effective cryopreservation protocols for whooping (Grus americana) and white-naped (Grus vipio) cranes, through examining the influences of two permeating (DMA and Me₂SO) and one non-permeating (sucrose) cryoprotectants, as well as vitamin E on post-thaw sperm survival. In Study 1, ejaculates (whooping: n = 10, white-naped: n = 8) were collected and cryopreserved in one of six cryo-diluents (crane extender with: DMA; DMA+0.1M sucrose; Me₂SO; Me₂SO+0.1M sucrose; 0.1M sucrose; 0.2M sucrose) using a two-step cooling method. Frozen samples were thawed and assessed for overall motility, motion characteristics, membrane integrity, morphology, and ability to bind to the inner perivitelline membrane (IPVM). In Study 2, whooping crane ejaculates (n = 17) were frozen in crane extender containing Me₂SO alone or with vitamin E (5 μg/mL or 10 μg/mL). Frozen samples were thawed and assessed as in Study 1, except the binding assay. White-naped crane sperm were more tolerant to cryopreservation than whooping crane (15% vs 6% post-thawed motility). In both species, sperm cryopreserved in medium containing Me₂SO alone displayed higher post thaw survival and ability to bind to IPVM than the other cryodiluent treatments. Vitamin E supplementation exerted no benefits to post thaw motility or membrane integrity. The findings demonstrated that there was species specificity in the susceptibility to cryopreservation. Nevertheless, Me₂SO was a preferred cryoprotectant for sperm from both whooping and white-naped cranes.