Comparison of assessment of fowl sperm viability by eosin-nigrosin and dual fluorescence (SYBR-14/PI)

Development of assays for the characterization of sperm motility parameters, viability, and membrane integrity in the epididymis and vas deferens of the greater rhea (Rhea americana)

The objectives of the study were to (1) describe the kinematic parameters of spermatozoa (2) compare methods of evaluating sperm viability (3) validate assays of functionality and integrity of the sperm membrane and (4) evaluate possible changes between spermatozoa from the epididymis and the vas deferens of the greater rhea. Semen samples were recovered from 7 adult individuals. Sperm motility was characterized by adjusting the set-up for Computer-assisted semen analysis (CASA) to that new species. For sperm viability evaluation, smears of bromophenol blue and eosin-nigrosine dyes were used. Five solutions of different osmolarities were then tested for the hypoosmotic swelling test (HOST). The combination of fluorescent probes (propidium iodide - IP and Hoechst 33342) was also used to assess plasma membrane integrity. Data were presented as mean ± SEM. Rhea spermatozoa from the vas deferens had an overall motility of 14.6 ± 2.5%. The bromophenol blue staining technique revealed that 64.6 ± 5.2% sperm were viable, while that proportion was 72.1 ± 2.5% using eosin-nigrosine. An average of 77.6 ± 4.8% of spermatozoa reacted to the HOST with distilled water at 0 mOsm/l. Fluorescent probes indicated that 65.3 ± 2.6% of spermatozoa had intact membranes. Interestingly, no statistical differences were observed between the parameters analyzed in the epididymal spermatozoa and the vas deferens. These new assays set reference values that can now be used to further exploration of sperm handling conditions and freezing protocols in rheas.

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.

Supplementing semen extenders with a combination of phosphorus and vitamin B12 Improves post-thawed cryopreserved rooster semen quality

Semen cryopreservation is an important technique for preserving the genetic material of numerous species. However, frozen semen is highly susceptible to sperm DNA damage and reduced motility, resulting in decreased fertility. The standard method for cryopreservation and several approaches have not been elucidated. This study aimed to determine the effects of supplementing rooster semen extender with a combination of phosphorus and vitamin B12 on cryopreserved semen quality. Semen was collected weekly via dorso-abdominal massage from 57 Burmese × Vietnam-crossbred Thai native roosters aged 1-3 years. In total, 139 semen samples were collected, pooled, and diluted to 200 million sperm per dose. The pooled sample was divided into six experimental groups: a control group (0.00%) diluted with modified Beltville Poultry Semen Extender (BPSE) and five treatment groups diluted with modified BPSE supplemented with phosphorus and vitamin B12 at concentrations 0.02, 0.04, 0.06, 0.08, and 0.10%, respectively. The semen samples were frozen and evaluated at 0, 15, and 30 min after thawing. Sperm kinematic parameters were determined using a computer-assisted sperm analysis system. Sperm quality was evaluated by measuring sperm viability, mitochondrial activity, acrosome integrity, and plasma membrane integrity. Statistical analyses were performed using a general linear mixed model (MIXED) in SAS. Factors in the statistical model were experimental groups, time after thawing, and interaction between experimental groups and time after thawing. Total and progressive motilities were greater in semen supplemented with 0.04% phosphorus and vitamin B12 compared with those in the control (p < 0.05). At 15 min post-thawing, VCL, VAP, and HPA in the 0.04% phosphorus and vitamin B12 supplementation group was greater than that in the control (p < 0.05). Phosphorus and vitamin B12 supplementation did not affect sperm kinematics at 0 and 30 min after thawing (p > 0.05). All the sperm parameters that were tested for the 0.04% phosphorus and vitamin B12 supplementation group in modified BPSE were the highest at all the timepoints after thawing. Thus, supplementing frozen semen extender with 0.04% phosphorus and vitamin B12 increased sperm motility, sperm kinematic parameters, and sperm quality.

[Computergestützte Spermaanalyse bei Großfalken (Falco spp.) und Vergleich zu den Ergebnissen konventioneller spermatologischer Untersuchungen]

OBJECTIVE

Numerous raptor species including some falcon species are facing continuous population decline in the wild and some are threatened by extinction. To support these species, captive breeding and reintroduction programs are attempted. Besides conservation, some large falcon species are commonly used in falconry and therefore bred commercially. Assisted reproduction is established in falcon breeding since the 1970s and semen analysis is an integral part to enable assessment of breeding males, inclusion or exclusion of semen donors and quality control of semen prior to artificial insemination. Conventional methods for semen analysis are widely used, but are time consuming and depend on the investigator's experience and ability. Computer-assisted semen analysis (CASA) would offer an objective, fast and reproducible alternative, but as they have not been established in large falcon species, this was the aim of this study.

MATERIAL AND METHODS

To this end, we examined in 3 breeding seasons 109 semen samples of gyr-saker hybrid falcons (n=2) and peregrine falcons (n=4) in 940 fields of view using the Minitube CASA SpermVision and compared these results to results of conventional methods of semen analysis. We used a preprogrammed setting and adapted two settings of CASA according to specific semen characteristics of falcons.

RESULTS

Sperm velocity, motility and viability parameters were recorded successfully using CASA. Correlation of conventional and computer-assisted motility analysis improved during the process of adaptation of CASA settings, but both methods differed significantly due to misinterpretation of round bodies and semen impurities by CASA. Viability values of conventional and computer assisted viability analysis using SYBR-PI correlated significantly while sperm concentration did not at all.

CONCLUSION

CASA failed to replace conventional semen analysis regarding sperm motility and sperm concentration using 3 different settings, as a reliable differentiation between spermatozoa, spermatids and round bodies was not achieved.

CLINICAL RELEVANCE

Using CASA, sperm velocity parameters were measured in spermatozoa of captive-bred large falcons for the first time and may be used as orientation values.

Establishment of methods to analyze the structural and functional integrity of the quail (Coturnix coturnix japonica) sperm plasma membrane

1. The objectives of this study were to establish the use of the fluorophores Hoechst 33342 and propidium iodide for the evaluation of sperm plasma membrane integrity and to identify an adequate hypoosmotic solution for the evaluation of sperm membrane functionality in quails.2. Sperm samples were collected from the vas deferens of nine quails. After initial evaluation, the samples were subjected to a flash-frozen assay. Three treatments with the following proportions of fresh sperm and sperm subjected to flash freezing were prepared as follows: 100:0 (T100), 50:50 (T50), and 0:100 (T0). The hypoosmotic swelling test used distilled water (0 mOsm/l) and fructose solutions (50, 100, and 200 mOsm/l).3. Immediately after recovery, the samples showed 75.6 ± 5.0% motility with vigour of 3.7 ± 0.3 and 96.1 ± 0.5% of the sperm appeared normal. The membrane integrity test showed 62.2 ± 5.2% intact sperm at T100, 29.0 ± 4.1% at T50 and 0.1 ± 0.1% at T0. Moreover, a greater number of reactive sperm (74.7 ± 6.7%) were observed when incubated in distilled water (0 mOsm/l) in comparison to other solutions (P < 0.05).4. The association of fluorescent probes composed of Hoechst 33342 and propidium iodide provided an efficient assessment of the integrity of the plasmatic membrane of quail spermatozoa. However, the study identified that the hypoosmotic swelling test has little predictive value regarding sperm membrane functionality in this species.

Use of native chicken breeds (Gallus gallus domesticus) for the development of suitable methods of Cantabrian capercaillie (Tetrao urogallus cantabricus) semen cryopreservation

Background

The Cantabrian capercaillie (Tetrao urogallus cantabricus) is critically endangered. This subspecies has the lowest genetic variability and it is in regression. It belongs to Phasianidae family; therefore, the domestic chicken (Gallus gallus domesticus) could be a good model for developing reproductive technologies for use in capercaillie populations with low availability of animals.

Objectives

In this study, we analyzed the response of capercaillie sperm to the freezing–thawing process for contributing to the development of a semen cryobank of Cantabrian capercaillie.

Methods

We used domestic chicken as the animal model in order to obtain the freezing protocol before applying on capercaillie. In the first experiment, two different extenders (EK and LR84) and different concentrations [4% and 6% dimethyl‐acetamide (DMA) v:v] of cryoprotectants were evaluated using in‐straw freezing method in domestic chickens. A pilot study in capercaillie males, using the same conditions evaluated in chicken, was performed.

Results

In chicken, we found that the LR84‐4% DMA media provided the best results for freezing semen. In capercaillie study, LR84 extender seemed to be the most appropriate diluent and 4% was the better dose of DMA cryoprotectant agent. Further, based on previous studies carried out in rooster samples, we also tested the glycerol (8% v/v) as a cryoprotectant for capercaillie semen cryopreservation.

Conclusions

Our results suggest that sperm from both domestic and wild species had a similar response to freezing–thawing processes. Mediterranean chickens may be used as a suitable model for developing sperm freezing protocols that can be extrapolated to threatened capercaillie populations. In addition, LR84 media with glycerol was the most efficient extender to freeze capercaillie sperm native.

Assisted Reproduction Techniques to Improve Reproduction in a Non-Model Species: The Case of the Arabian Bustard (Ardeotis arabs) Conservation Breeding Program

Simple Summary

Artificial reproduction technologies such as artificial insemination and semen cryopreservation are important tools for species conservation and long-term genetic management. As with many bird species, Arabian bustard (Ardeotis arabs) populations are declining and are already extinct in some regions. The International Fund for Houbara Conservation (IFHC) has started a conservation breeding program for the Arabian bustard in the United Arab Emirates (UAE). Birds were housed by pairs to allow natural reproduction. Out of 1253 eggs laid, 1090 were incubated, of which 379 were fertile (i.e., 34.8%). In total, this led to the production of 251 chicks. Due to lower than desired fertility, we introduced assisted reproduction techniques to increase fertility and develop zootechnical knowledge for the species. This paper presents the results of semen collection, artificial insemination, and semen cryobanking in Arabian bustards. Inseminations with both fresh and preserved semen led to a significant increase in fertility to 84.3% of incubated eggs (i.e., 43 out of 51 incubated eggs laid by previously artificially inseminated females). Furthermore, we confirmed the viability of cryopreserved semen and its fertilizing capacity. Our results demonstrate the usefulness of artificial reproduction techniques for the conservation of Arabian bustards and suggest that these techniques can be applied to closely related critically endangered species with a minimum of adaptation.

Abstract

Artificial reproductive technologies are highly valuable for ex situ conservation. While Arabian bustard populations are declining and extinct in some parts of the range, the International Fund for Houbara Conservation in the United Arab Emirates implemented a conservation breeding program. Since 2012, a total of 1253 eggs were laid through natural reproduction, 1090 were incubated and 379 of these were fertile (fertility rate of 34.8%), leading to the production of 251 chicks. To improve fertility and acquire crucial knowledge for other endangered large birds, artificial reproduction was implemented in 2018 using fresh, refrigerated, and frozen sperm. A total of 720 ejaculates were collected from 12 birds. We analysed these samples for concentration, volume, motility score (0 to 5), viability (eosin/nigrosine), length, and morphology. The first age at collection was 35.7 ± 18.8 months, mean volume was 89.2 ± 65.3 µL, mean concentration was 928 ± 731 sptz/mL and mean motility score was 2.61 ± 0.95. Morphology analyses revealed a bimodal distribution of sperm length. Five hundred and thirty-five ejaculates were cryopreserved and the initial motility score was 3.4 ± 0.7 and 2.0 ± 0.6 after thawing, while the percentage of normal and intact membrane sperm cells decreased from 88.8 ± 7.5% to 52.9 ± 1%. Sixty-five artificial inseminations were performed, leading to a global fertility rate of 84.3%—more precisely, 85.2% and 83.3%, respectively, for fresh and cryopreserved semen. All methods successfully produced fertile eggs, indicating that artificial insemination is an efficient tool for the conservation and genetic management of the species.

Evaluation of Semen Quality of Jeju Black Cattle (JBC) to Select Bulls Optimal for Breeding and Establish Freezing Conditions Suitable for JBC Sperm

Simple Summary

Jeju black cattle, a type of native Korean cattle characterized by black fur covering the entire body, inhabit Jeju Special Self-Governing Province, a World Natural Heritage Site. Although this breed was state designated as a natural monument in 2013 due to its characteristics and genetic traits, it is on the verge of extinction and thus there is a need to preserve this breed and further improve its traits. Therefore, we evaluated sperm motility, vitality, and morphology, which have long been considered good predictors of fertility in the absence of female infertility factors. Our findings showed that the semen of the JBC-A bull was superior to the semen of four other JBC bulls. Due to the aging of the population of JBC breeding bulls, strategies should be devised to improve sperm production in vivo.

Abstract

To optimize the reproduction of Jeju black cattle (JBC), freezing conditions for sperm were established and sperm motility, vitality, morphology, and fertility were evaluated to select the optimal bull for breeding. Semen samples from five JBC bulls were individually mixed with freezing medium at a final concentration of 1 × 108 sperm/mL and frozen in liquid nitrogen vapor at a height of 3 or 7 cm (referred to as 3 cm sperm and 7 cm sperm, respectively). When the freezing conditions were compared, the motility of 7 cm sperm was significantly higher than that of 3 cm sperm for the JBC-A bull. The motility, curvilinear velocity, straight-line velocity, and average path velocity of fresh and frozen–thawed sperm were the highest for the JBC-A bull. The vitalities of fresh and frozen–thawed sperm were the highest for the JBC-A/E and JBC-A bulls, respectively. The percentage of normal cells in fresh sperm was the highest for the JBC-D bull. The rates of the normal formation of two pronuclei and total sperm penetration were the highest in zygotes fertilized with sperm from the JBC-A bull. The sperm from the JBC-A bull had superior qualities and are thus the most appropriate choice for the preservation and reproduction of these endangered cattle.

Reproductive toxicity of roundup®-treated feed on broiler breeder roosters and the amelioration of these deleterious effects with inclusion of humic acids in feed

Glyphosate-based herbicides (GBHs) such as RoundUp® are a staple of modern crop production, and as a result, residues of their ingredients are typically found in animal feeds. GBH ingredients have repeatedly been shown to impact the male reproductive health of various animals, but at present, the impact of GBH exposures on reproductive health have not been investigated in broiler breeder roosters. This study sought to determine the effect of these exposures on roosters as well as the ability of humic acids (HA) to counteract the effect of GBH exposure. Through 18 weeks of treatment with Roundup®-added or HA-added feeds compared against a common broiler breeder mash, negative effects of Roundup® exposure were seen on testis morphology as well as sperm quality. Increased exposure to Roundup® ingredients resulted in increased vacuolation of seminiferous tubule epithelium. Exposure to Roundup® impacted assessments of sperm quality including sperm mobility, viability and count during the experimental trail. HA supplementation served as a promising adsorptive additive by improving both morphology and sperm quality during the trial. Roundup® exposure was shown to have a negative influence on broiler breeder rooster reproductive health while HA improved reproductive health. The use of HA as an absorbent additive in broiler breeder feeds shows promise in improving reproductive efficiency in broiler breeders.

Birchen and Blue Leonesa sperm cryopreservation: a new technique for evaluating the integrity of cockerel sperm membranes

1. Birchen and Blue Leonesa are two endangered chicken breeds mainly raised in Curueño Valley in North Spain. The establishment of a germplasm bank to guarantee the preservation of these breeds is needed. However, cockerels from different breeder flocks can show variance in semen cryoresistance.2. The following work focused on the sperm characterisation and cryopreservation of Birchen and Blue Leonesa cockerels from four different breeders. A total of 30 semen pools were analysed. Besides conventional sperm analysis, including motility by computer-aided sperm analysis (CASA) and DNA fragmentation by TUNEL, the present study tested a double staining method (MitoTracker^TM Green FM/propidium iodide). This gave simultaneous assessment of plasma and acrosomal and mitochondrial membranes, which were previously validated by SYBR-14/PI, CASA, aniline blue and TUNEL.3. No significant differences were found among fresh semen variables between breeds and breeders. For post-thawed variables, significant differences (P < 0.05) were found between breeders in sperm viability (58.0 ± 1.90 breeder D vs. 35.2 ± 7.41 breeder A, 37.2 ± 4.09 breeder B and 22.3 ± 5.92 breeder C) and DNA fragmentation (62.4 ± 9.91 breeder C vs. 31.8 ± 7.08 breeder B and 24.5 ± 5.49 breeder D). The lowest DNA fragmentation values for semen from breeder D birds were coincident with higher integrity of the mitochondrial membrane.4. The results revealed higher sperm cryoresistance in the cockerels from one of the breeders, possibly due to differences in management system (e.g. diet, housing, control of stress elements and pathogens, reproduction practices or maintenance of genetic diversity). These differences may determine the sperm freezability, and thus the effectiveness of developing a germplasm bank.

Sperm Cryopreservation in American Flamingo (Phoenicopterus Ruber): Influence of Cryoprotectants and Seminal Plasma Removal

The American flamingo is a useful model for the development of successful semen cryopreservation procedures to be applied to threatened related species from the family Phoenicopteridae, and to permit genetic material banking. Current study sought to develop effective sperm cryopreservation protocols through examining the influences of two permeating cryoprotectants and the seminal plasma removal. During two consecutive years (April), semen samples were collected and frozen from American flamingos. In the first year, the effect of two permeating cryoprotectants, DMA (dimethylacetamide) (6%) or Me2SO (dimethylsulphoxide) (8%), on frozen-thawed sperm variables were compared in 21 males. No differences were seen between DMA and Me2SO for sperm motility, sperm viability, and DNA fragmentation after thawing. In the second year, the role of seminal plasma on sperm cryoresistance was investigated in 31 flamingos. Sperm samples were cryopreserved with and without seminal plasma, using Me2SO (8%) as a cryoprotectant. The results showed that samples with seminal plasma had higher values than samples without seminal plasma for the following sperm variables: Straight line velocity (22.40 µm/s vs. 16.64 µm/s), wobble (75.83% vs. 69.40%), (p < 0.05), linearity (62.73% vs. 52.01%) and straightness (82.38% vs. 73.79%) (p < 0.01); but acrosome integrity was lower (55.56% vs. 66.88%) (p < 0.05). The cryoresistance ratio (CR) was greater in samples frozen with seminal plasma than without seminal plasma for CR-progressive motility (138.72 vs. 54.59), CR-curvilinear velocity (105.98 vs. 89.32), CR-straight line velocity (152.77 vs. 112.58), CR-average path velocity (122.48 vs. 98.12), CR-wobble (111.75 vs. 102.04) (p < 0.05), CR-linearity (139.41 vs. 113.18), and CR-straightness (124.02 vs. 109.97) (p < 0.01). This research demonstrated that there were not differences between Me2SO and DMA to successful freezing sperm of flamingos; seminal plasma removal did not provide a benefit for sperm cryopreservation.

Effect of supplementation of valine to chicken extender on sperm cryoresistance and post-thaw fertilization capacity

Recent reports showed a positive correlation between frozen-thawed rooster sperm DNA integrity and the concentrations of valine in seminal plasma. The present study evaluated the effect of supplementing valine to semen extender for freezing sperm of 2 endangered local Spanish chicken breeds with different sperm cryoresistance: Red Villafranquina (VF) showing low sperm DNA integrity after cryopreservation and Quail Castellana that shows higher DNA integrity. One pool of semen per breed was obtained twice a week for 10 wk (n = 40, 20 per breed). Each pool was divided into 2 fractions. One of these fractions was frozen in presence of valine as additive in the extender (concentration 10 mmol), whereas the other was used as control. The evaluation of the samples before and after freezing-thawing included motility (CASA-Mot system), viability (propidium iodide and SYBR-14), DNA integrity (terminal deoxynucleotidyl transferase dUTP nick end labeling), and fertility rate (percentage of eggs with blastoderm development after artificial insemination). Supplementation of valine increased several motility variables of fresh semen. In VF breed, valine increased percentage of progressive motile sperm (P = 0.025), curvilinear velocity (P = 0.033), straight-line velocity (P = 0.040), and average path velocity (P = 0.033), whereas progressive motile sperm (P = 0.019), curvilinear velocity (P = 0.006), straight-line velocity (P = 0.003) and average path velocity (P = 0.004) were improved in the Quail Castellana breed. Valine addition increased the DNA integrity of cryopreserved semen (decreased post-thaw DNA fragmentation) in both breeds, with a significant effect (P = 0.002) in VF (36.3% VF-control vs 31%VF-valine). As expected, Quail Castellana cryopreserved sperm control showed higher fertility rate (34.4% ± 12.1) than VF cryopreserved sperm control (16.1% + 6.2). Supplementing valine to the freezing extender doubled (P = 0.026) the fertility rate of VF (32.6% ± 12.2) compared with the control (16.1% + 6.2). In conclusion, supplementation of valine to chicken freezing extenders shows a positive effect on DNA fragmentation and fertilizing ability of frozen-thawed sperm, with a better response in a breed considered as the lowest freezer in our conservatory.

Viability assessment of spermatozoa in large falcons (Falco spp.) using various staining protocols

Viability assessment is an important part of semen analysis, and various live/dead staining protocols have been used in semen of avian species. Results of live/dead count differed between dyes, staining protocols and bird species, impeding comparability between studies and requiring species-specific comparisons of viability stains. In raptor semen, similar comparisons are absent. Thus, the aim of the present study was to compare eight conventional viability stains. Eosin blue 2% [EB], eosin blue 2% with the addition of 3% sodium citrate [EB2], eosin blue-nigrosin 5% [EBN5], eosin yellow-nigrosin 5% [EYN5], eosin yellow-nigrosin 10% [EYN10], eosin blue-aniline blue [EBA], eosin yellow-aniline blue [EYA] and bromophenol blue-nigrosin [BBN] were evaluated in comparison with the fluorescence stain SYBR^® Green-propidium iodide [SYBR-PI] in spermatozoa of falcons. The comparison was performed using conventional light microscopy which is applicable in breeding centres, veterinary practices and field studies. Additionally, live/dead stains were correlated to motility values of the same samples to validate sperm viability. Light microscopy using EB and using SYBR-PI enabled an effective and clear differentiation between alive and dead spermatozoa of falcons. Motility values correlated significantly and strongly with EB only (r = .629; p < .001), but not with any other stain used in the study. Therefore, our results suggest EB as the most suitable stain for viability assessment in the semen of large falcons.

Effect of semen extenders and storage time on quality of Muscovy duck (Cairina moschata) drake semen during the entire reproductive season

Avian semen dilution with appropriate extender allows to prolong the fertilizing ability of sperm stored in vitro. In the present study, the impact of extenders and time of storage on morphology of Muscovy duck (Cairina moschata) drake semen were examined. Semen was collected twice a week, using male stimulation by a female method, from 12 adults (29 weeks old) drakes kept individually in cages, under controlled environmental conditions. Freshly collected, pooled ejaculates were divided into three part: neat undiluted sample, and diluted 1:1 with Schramm (SCH) or Watanabe (W) extender and stored at 4°C. Morphological examination of all samples was conducted after dilution and then, after 3 and 6 hr of storage. The storage of undiluted semen caused decrease (p ≤ .01) in live morphologically normal sperm, from 79.73% in the freshly collected ejaculates to 55.75% and to 12.12% after 3 and 6 hr of storage, respectively (average calculated for the entire reproductive season). In the semen diluted with Schramm's extender the adequate values attained 86.84, 79.65 and 61.66%, and using Watanabe extender 84.77, 83.58 and 75.25%, respectively. The period of semen storage and the type of extender caused significant (p ≤ 0,05; p ≤ 0,01) changes in sperm morphology. The longer period of storage contributed to the decrease in number of morphologically normal sperm, whereas their content in Watanabe extender after 3 and 6 hr of storage was higher (p ≤ .01) than in semen diluted in Schramm extender.

Seminal Plasma Proteome as an Indicator of Sperm Dysfunction and Low Sperm Motility in Chickens

Molecular mechanisms underlying sperm motility have not been fully explained, particularly in chickens. The objective was to identify seminal plasma proteins associated with chicken sperm motility by comparing the seminal plasma proteomic profile of roosters with low sperm motility (LSM, n = 4) and high sperm motility (HSM, n = 4). Using a label-free MS-based method, a total of 522 seminal plasma proteins were identified, including 386 (∼74%) previously reported and 136 novel ones. A total of 70 differentially abundant proteins were defined, including 48 more-abundant, 15 less-abundant, and seven proteins unique to the LSM group (specific proteins). Key secretory proteins like less-abundant adhesion G-protein coupled receptor G2 (ADGRG2) and more-abundant serine peptidase inhibitor Kazal-type 2 (SPINK2) in the LSM suggested that the corresponding secretory tissues played a crucial role in maintaining sperm motility. Majority (80%) of the more-abundant and five specific proteins were annotated to the cytoplasmic domain which might be a result of higher plasma membrane damage and acrosome dysfunction in LSM. Additionally, more-abundant mitochondrial proteins were detected in LSM seminal plasma associated with lower spermatozoa mitochondrial membrane potential (ΔΨm) and ATP concentrations. Further studies showed that the spermatozoa might be suffering from oxidative stress, as the amount of spermatozoa reactive oxygen species (ROS) were largely enhanced, seminal malondialdehyde (MDA) concentrations were increased, and the seminal plasma total antioxidant capacity (T-AOC) were decreased. Our study provides an additional catalogue of chicken seminal plasma proteome and supports the idea that seminal plasma could be as an indicator of spermatozoa physiology. More-abundant of acrosome, mitochondria and sperm cytoskeleton proteins in the seminal plasma could be a marker of sperm dysfunction and loss of motility. The degeneration of spermatozoa caused by the reduced seminal T-AOC and enhanced oxidative stress might be potential determinants of low sperm motility. These results could extend our understanding of sperm motility and sperm physiology regulation.

The seminal acrosin-inhibitor ClTI1/SPINK2 is a fertility-associated marker in the chicken

The seminal plasma is a very complex fluid, which surrounds sperm in semen. It contains numerous proteins including proteases and protease inhibitors that regulate proteolytic processes associated with protein activation and degradation. We previously identified a seminal protein, chicken liver trypsin inhibitor 1 (ClTI-1) over expressed in semen of roosters with high fertility, suggesting a role in male fertility. In the present study, we showed that ClTI-1 gene is actually SPINK2. Using normal healthy adult roosters, we showed that SPINK2 amount in seminal plasma was positively correlated with male fertility in chicken lines with highly contrasted genetic backgrounds (broiler and layer lines). Using affinity chromatography combined to mass spectrometry analysis and kinetic assays, we demonstrated for the first time that two chicken acrosin isoforms (acrosin and acrosin-like proteins) are the physiological serine protease targets of SPINK2 inhibitor. SPINK2 transcript was overexpressed all along the male tract, and the protein was present in the lumen as expected for secreted proteins. Altogether, these data emphasize the role of seminal SPINK2 Kazal-type inhibitor as an important actor of fertility in birds through its inhibitory action on acrosin isoforms proteins.

Seminal plasma amino acid profile in different breeds of chicken: Role of seminal plasma on sperm cryoresistance

Seminal plasma is a key biological fluid that modulates sperm function in the reproduction process. However, its role in sperm biotechnologies is scarce in poultry. The aims of the present study were to study the amino acids profile and total proteins of seminal plasma in 12 Spanish chicken breeds and to investigate the role of seminal plasma on cryoresistance of rooster sperm. To investigate the role of seminal plasma on cryoresistance, diluted pooled semen samples were cryopreserved in the presence and absence of seminal plasma. Glutamic acid was the most abundant free amino acid in seminal plasma, followed by alanine, serine, valine, and glycine. There was an influence of breed (P<0.05) on the percentage of viable sperm after freezing-thawing of samples with seminal plasma. Cluster analysis revealed that White Prat, Black Castellana, Blue Andaluza, Quail Castellana, and Red-Barred Vasca returned the best freezing-thawing response (good freezers). There was a positive correlation between seminal plasma concentrations of valine, isoleucine lysine, leucine and post thaw viability. The evaluation of fertilization capacity of frozen-thawed semen from the breeds White Prat ('good freezer') and Black-Red Andaluza ('bad freezer') showed that good freezer had higher fertility (20/68, 29.4%) compared to bad freezer breed (14/76, 18.4%), even if the difference was not significant (P = 0.08). The TUNEL assay revealed that freezing/thawing procedures in presence of seminal plasma provoked higher DNA fragmentation in most of the breeds, with a positive correlation between seminal alanine, valine, isoleucine, methionine, leucine, tyrosine, phenylalanine concentrations and DNA integrity. DNA fragmentation was lower in absence of seminal plasma and the breed effect on sperm viability was highly reduced. It is concluded that specific seminal plasma amino acids were associated with post-thaw percentage of viable sperm and DNA integrity. The removal of seminal plasma decreases the variability of the results and DNA fragmentation damages.

Semen cryopreservation in black-footed (Spheniscus demersus) and gentoo (Pygoscelis papua) penguins: Effects of thawing temperature on semen characteristics

In this study, there was an examination of the effect on the characteristics of cryopreserved black-footed (Spheniscus demersus) and gentoo (Pygoscelis papua) penguin semen, of thawing at 37 and 5 °C. For two consecutive years, semen was collected and frozen during the April-June period from six gentoo penguins, and during the October-November period from 13 black-footed penguins. After thawing, sperm motility variables were examined by computer-assisted sperm analysis. Propidium iodide and SYBR-14 were used as fluorochromes for the examination of membrane integrity. For the gentoo penguins, no differences were detected in the values of frozen-thawed semen characteristics after thawing at 37 or 5 °C. For the black-footed penguins, however, thawing at 5 °C resulted in greater values (P < 0.05) for straight-line velocity (VSL), average path velocity (VAP), linearity (LIN), straightness (STR), and wobble (WOB) as compared with thawing at 37 °C. After thawing at 37 ºC, there were greater values with gentoo penguin sperm for percentage motile sperm, progressive motility, curvilinear velocity (VCL), VSL VAP, LIN, STR, WOB and beat-cross frequency (BCF; P < 0.05) than that for black-footed penguin sperm. After thawing at 5 ºC, there were no differences in values for any variables between the two species. In conclusion, thawing temperature affects semen characteristics in a species-specific manner. The present data strongly suggest that cryopreservation procedures should be adapted for use with each penguin species. Cryopreserved black-footed penguin semen should be thawed after cryopreservation at 5 ºC, while that of gentoo penguins can be thawed at either 5 or 37 ºC.

Evaluation of cockerel spermatozoa viability and motility by a novel enzyme based cell viability assay

1. The results of spermatozoa assessment by the WST-8 (2-[2-methoxy-4-nitrophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H-tetrazolium, monosodium salt) assay, flow cytometry (FC) or computer-assisted sperm analysis (CASA) were compared. 2. Different live/killed ratios of cockerel semen were serially diluted to 120, 60, and 30 × 10⁶ cells/ml, and each sample was analysed by (1) WST-8 assay at 0, 10, 20, 30, 40, 50, 60 min, (2) viability with FC, and (3) motility with CASA. 3. The WST-8 reduction rate was closely correlated with spermatozoa viability and motility. The optimal semen concentration for the WST-8 assay was 120 × 10⁶ cells/ml, and the standard curves for spermatozoa viability and motility predictions, respectively, were y_viability60 = 162.8x + 104.96 (R² = 0.9594) after 60 min of incubation and y_motility40 = 225.09x + 96.299 (R² = 0.8475) after 40 min of incubation. 4. It was concluded that the WST-8 assay is useful for the practical evaluation of cockerel spermatozoa viability and motility. Compared to FC and CASA, the WST-8 assay does not require expensive and complex instrumentation in the lab. Furthermore, one well of the WST-8 reaction can be used to predict spermatozoa viability and motility at the same time, which all lead it to be efficient and economical for semen quality assessment.

Ameliorative effects of bee pollen and date palm pollen on the glycemic state and male sexual dysfunctions in streptozotocin-Induced diabetic wistar rats

This study aimed to assess the effects of bee pollen (BP) and/or date palm pollen (DPP) suspensions on the glycemic state, testicular dysfunctions, oxidative stress and antioxidant defense system in streptozotocin (STZ)-induced diabetic male Wistar rats. Diabetes mellitus was induced by single intraperitoneal injection of STZ to overnight-fasted rats at dose of 40mg/kg body weight. After 1 week of STZ injection, diabetic rats were treated with BP and/or DPP suspensions at dose levels of 100mg/kg body weight/day for 4 weeks. The STZ-induced diabetes significantly increased blood glucose levels and testicular nitric oxide (NO) and malondialdehyde (MDA) levels parallel with disrupted testicular and pancreatic histological architecture and integrity. On the other hand, STZ-induced diabetes significantly decreased body weight, testis and pancreas weights, levels of serum insulin, testosterone, luteinizing hormone (LH) & follicle stimulating hormone (FSH) as well as sperm count, motility and viability. The administration of BP and DPP suspensions resulted in a significant recovery of the above mentioned parameters as compared to the diabetic control group. These improvements were associated with enhancement of the testicular antioxidant system manifested by an increase in the lowered glutathione content (GSH) and glutathione-S-transferase (GST), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in diabetic rats as a result of treatments with BP and DPP suspensions. Thus, it can be concluded that BP and/or DPP suspensions may have potential protective role against diabetes-induced pituitary testicular axis dysfunction and testicular histological deleterious changes in association with antihyperglycemic actions via their antioxidant properties and their efficiency to improve blood insulin level and beta cell function.

Intact Cell MALDI-TOF MS on Sperm: A Molecular Test For Male Fertility Diagnosis

Currently, evaluation of sperm quality is primarily based on in vitro measures of sperm function such as motility, viability and/or acrosome reaction. However, results are often poorly correlated with fertility, and alternative diagnostic tools are therefore needed both in veterinary and human medicine. In a recent pilot study, we demonstrated that MS profiles from intact chicken sperm using MALDI-TOF profiles could detect significant differences between fertile/subfertile spermatozoa showing that such profiles could be useful for in vitro male fertility testing. In the present study, we performed larger standardized experimental procedures designed for the development of fertility- predictive mathematical models based on sperm cell MALDI-TOF MS profiles acquired through a fast, automated method. This intact cell MALDI-TOF MS-based method showed high diagnostic accuracy in identifying fertile/subfertile males in a large male population of known fertility from two distinct genetic lineages (meat and egg laying lines). We additionally identified 40% of the m/z peaks observed in sperm MS profiles through a top-down high-resolution protein identification analysis. This revealed that the MALDI-TOF MS spectra obtained from intact sperm cells contained a large proportion of protein degradation products, many implicated in important functional pathways in sperm such as energy metabolism, structure and movement. Proteins identified by our predictive model included diverse and important functional classes providing new insights into sperm function as it relates to fertility differences in this experimental system. Thus, in addition to the chicken model system developed here, with the use of appropriate models these methods should effectively translate to other animal taxa where similar tests for fertility are warranted.

Calcium channels in chicken sperm regulate motility and the acrosome reaction

Intracellular cytoplasmic calcium ([Ca(2+) ]i ) has an important regulatory role in gamete functions. However, the biochemical components involved in Ca(2+) transport are still unknown in birds, an animal class that has lost functional sperm-specific CatSper channels. Here, we provide evidence for the presence and expression of various Ca(2+) channels in chicken sperm, including high voltage-activated channels (L and R types), the store-operated Ca(2+) channel (SOC) component Orai1, the transient receptor potential channel (TRPC1) and inositol-1,4,5-trisphosphate receptors (IP3 R1). L- and R-type channels were mainly localized in the acrosome and the midpiece, and T-type channels were not detected in chicken sperm. Orai1 was found in all compartments, but with a weak, diffuse signal in the flagellum. TRCP1 was mainly localized in the acrosome and the midpiece, but a weak diffuse signal was also observed in the nucleus and the flagellum. IP3 R1 was mainly detected in the nucleus. The L-type channel inhibitor nifedipine, the R-type channel inhibitor SNX-482 and the SOC inhibitors MRS-1845, 2-APB and YM-58483 decreased [Ca(2+) ]i sperm motility and acrosome reaction capability, with the SOC inhibitors inhibiting these functions most efficiently. Furthermore, we showed that Ca(2+) -mediated induction of AMP-activated protein kinase (AMPK) phosphorylation was blocked by SOC inhibition. Our identification of important regulators of Ca(2+) signaling in avian sperm suggests that SOCs play a predominant role in gamete function, whereas T-type channels may not be involved. In addition, Ca(2+) entry via SOCs appears to be the most likely pathway for AMPK activation and energy-requiring sperm functions such as motility and the acrosome reaction.

Ca2+/Calmodulin-Dependent Protein Kinase Kinases (CaMKKs) Effects on AMP-Activated Protein Kinase (AMPK) Regulation of Chicken Sperm Functions

Sperm require high levels of energy to ensure motility and acrosome reaction (AR) accomplishment. The AMP-activated protein kinase (AMPK) has been demonstrated to be strongly involved in the control of these properties. We address here the question of the potential role of calcium mobilization on AMPK activation and function in chicken sperm through the Ca²⁺/calmodulin-dependent protein kinase kinases (CaMKKs) mediated pathway. The presence of CaMKKs and their substrates CaMKI and CaMKIV was evaluated by western-blotting and indirect immunofluorescence. Sperm were incubated in presence or absence of extracellular Ca²⁺, or of CaMKKs inhibitor (STO-609). Phosphorylations of AMPK, CaMKI, and CaMKIV, as well as sperm functions were evaluated. We demonstrate the presence of both CaMKKs (α and β), CaMKI and CaMKIV in chicken sperm. CaMKKα and CaMKI were localized in the acrosome, the midpiece, and at much lower fluorescence in the flagellum, whereas CaMKKβ was mostly localized in the flagellum and much less in the midpiece and the acrosome. CaMKIV was only present in the flagellum. The presence of extracellular calcium induced an increase in kinases phosphorylation and sperm activity. STO-609 reduced AMPK phosphorylation in the presence of extracellular Ca²⁺ but not in its absence. STO-609 did not affect CaMKIV phosphorylation but decreased CaMKI phosphorylation and this inhibition was quicker in the presence of extracellular Ca²⁺ than in its absence. STO-609 efficiently inhibited sperm motility and AR, both in the presence and absence of extracellular Ca²⁺. Our results show for the first time the presence of CaMKKs (α and β) and one of its substrate, CaMKI in different subcellular compartments in germ cells, as well as the changes in the AMPK regulation pathway, sperm motility and AR related to Ca²⁺ entry in sperm through the Ca²⁺/CaM/CaMKKs/CaMKI pathway. The Ca²⁺/CaMKKs/AMPK pathway is activated only under conditions of extracellular Ca²⁺ entry in the cells.

Cryopreservation in fish: current status and pathways to quality assurance and quality control in repository development

Cryopreservation in aquatic species in general has been constrained to research activities for more than 60 years. Although the need for application and commercialisation pathways has become clear, the lack of comprehensive quality assurance and quality control programs has impeded the progress of the field, delaying the establishment of germplasm repositories and commercial-scale applications. In this review we focus on the opportunities for standardisation in the practices involved in the four main stages of the cryopreservation process: (1) source, housing and conditioning of fish; (2) sample collection and preparation; (3) freezing and cryogenic storage of samples; and (4) egg collection and use of thawed sperm samples. In addition, we introduce some key factors that would assist the transition to commercial-scale, high-throughput application.

Sperm Quality Parameters and Reproductive Efficiency in Muscovy Duck (Cairina moschata)

The in vitro sperm quality parameters (motility, M; viability, V; normal morphology, NM; plasma membrane integrity, PMI; mitochondrial function, MF) in Muscovy drakes (Cairina moschata) were evaluated by using microscopy and flow cytometry, the correlation among sperm quality parameters and results of artificial insemination was also assessed in present study. M, V and NM were detected by phase contrast microscopy assisted with eosinnigrosin staining, and PMI and MF were detected by using flow cytometry within appropriate fluorescence staining (SYBR-14/PI and R123/PI, respectively). Fertility (F), early embryonic mortality (EEM) and the survival embryo rate (SER) were assessed after the artificial insemination of Muscovy or Kaiya duck (Anas platyrhynchos) females. Sperm PMI and MF, the parameters detected by flow cytometry were positively correlated with sperm M, V, and NM, those were detected by phase contrast microscopy (P<0.05). Sperm V and PMI were negatively correlated with the percentage of early embryo mortality of Muscovy duck fertile eggs (P<0.05). The results of the present study showed the relationships among the AI results and the sperm quality parameters detected by microscopy as well as flow cytometry. In conclusion, flow cytometry assisted with microscopy can be an effective tool to evaluate in vitro sperm quality and may contribute to predict the reproductive performances of individual Muscovy drakes, which helps to improve duck production efficiency.

Influence of Post-Mortem Sperm Recovery Method and Extender on Unstored and Refrigerated Rooster Sperm Variables

Many post-mortem sperm collection techniques have been described for mammalian species, but their use in birds is scarce. This paper compares the efficacy of two post-mortem sperm retrieval techniques - the flushing and float-out methods - in the collection of rooster sperm, in conjunction with the use of two extenders, i.e., L&R-84 medium and Lake 7.1 medium. To determine whether the protective effects of these extenders against refrigeration are different for post-mortem and ejaculated sperm, pooled ejaculated samples (procured via the massage technique) were also diluted in the above extenders. Post-mortem and ejaculated sperm variables were assessed immediately at room temperature (0 h), and after refrigeration at 5°C for 24 and 48 h. The flushing method retrieved more sperm than the float-out method (596.5 ± 75.4 million sperm vs 341.0 ± 87.6 million sperm; p < 0.05); indeed, the number retrieved by the former method was similar to that obtained by massage-induced ejaculation (630.3 ± 78.2 million sperm). For sperm collected by all methods, the L&R-84 medium provided an advantage in terms of sperm motility variables at 0 h. In the refrigerated sperm samples, however, the Lake 7.1 medium was associated with higher percentages of viable sperm, and had a greater protective effect (p < 0.05) with respect to most motility variables. In conclusion, the flushing method is recommended for collecting sperm from dead birds. If this sperm needs to be refrigerated at 5°C until analysis, Lake 7.1 medium is recommended as an extender.

The 5'-AMP-Activated Protein Kinase (AMPK) Is Involved in the Augmentation of Antioxidant Defenses in Cryopreserved Chicken Sperm

Semen cryopreservation is a unique tool for the management of animal genetic diversity. However, the freeze-thaw process causes biochemical and physical alterations which make difficult the restoration of sperm energy-dependent functions needed for fertilization. 5'-AMP activated protein kinase (AMPK) is a key sensor and regulator of intracellular energy metabolism. Mitochondria functions are known to be severely affected during sperm cryopreservation with deleterious oxidative and peroxidative effects leading to cell integrity and functions damages. The aim of this study was thus to examine the role of AMPK on the peroxidation/antioxidant enzymes defense system in frozen-thawed sperm and its consequences on sperm functions. Chicken semen was diluted in media supplemented with or without AMPK activators (AICAR or Metformin [MET]) or inhibitor (Compound C [CC]) and then cryopreserved. AMPKα phosphorylation, antioxidant enzymes activities, mitochondrial potential, ATP, citrate, viability, acrosome reaction ability (AR) and various motility parameters were negatively affected by the freeze-thaw process while reactive oxygen species (ROS) production, lipid peroxidation (LPO) and lactate concentration were dramatically increased. AICAR partially restored superoxide dismutase (SOD), Glutathione Peroxidase (GPx) and Glutathione Reductase (GR), increased ATP, citrate, and lactate concentration and subsequently decreased the ROS and LPO (malondialdehyde) in frozen-thawed semen. Motility parameters were increased (i.e., + 23% for motility, + 34% for rapid sperm) as well as AR (+ 100%). MET had similar effects as AICAR except that catalase activity was restored and that ATP and mitochondrial potential were further decreased. CC showed effects opposite to AICAR on SOD, ROS, LPO and AR and motility parameters. Taken together, our results strongly suggest that, upon freeze-thaw process, AMPK stimulated intracellular anti-oxidative defense enzymes through ATP regulation, thus reducing ROS and lipid peroxidation, and consequently partially restoring several essential sperm functions and leading to a better quality of cryopreserved sperm.

Sperm-egg penetration assay assessment of the contraceptive effects of glycerol and egg yolk in rooster sperm diluents

Glycerol (GLY) and egg yolk (EY) are good cryoprotectants of avian and mammalian sperm, but in birds, they strongly inhibit the eventual fertilization of ova. Using the sperm penetration (SP-holes) assay and fertility trials, the present study investigates (1) the possible mechanism by which this contraceptive effect occurs in chickens and (2) the maximum concentrations of GLY and EY tolerated by fresh rooster sperm. Seventy Black-Barred Andaluza hens (five per treatment) were inseminated four times (twice per week) with 0.1 mL of fresh semen from roosters of the same breed diluted 1:1 (v:v) with Lake and Ravie medium containing different concentrations of GLY or EY. No adverse effects on acrosome integrity, sperm motility, or viability were seen with any concentration of GLY or EY. The number of SP-holes on perivitelline layer samples taken from above the germinal disc became progressively lower at GLY concentrations of 1.5% or greater (P > 0.05). No holes caused by sperms were seen in unfertilized eggs. The corresponding fertility results showed similar reductions when the GLY concentration was 1.5% or greater. No changes in the number of SP-holes were seen with increasing EY concentrations (0%-7.5%), nor were any differences in fertility observed, except for a reduction when 15% EY was used. The results therefore reveal that GLY affects the transit of sperms through the oviduct in their attempt to reach the infundibulum area, limiting their access to the ovum perivitelline layer. Egg yolk had no such effect, nor did it influence acrosome reaction capacity; its mechanism of contraceptive action therefore remains unknown. The maximum GLY and EY concentrations tolerated by the rooster sperm were 0.75% and 7.5%, respectively.

Assessment of changes in sperm cell membrane integrity occurring during the storage of semen from genetically different males using two diagnostic methods

Wysokińska, A. and Kondracki, S. 2014. Assessment of changes in sperm cell membrane integrity occurring during the storage of semen from genetically different males using two diagnostic methods. Can. J. Anim. Sci. 94: 601–606. The present study was carried out to assess changes in sperm cell membrane integrity occurring during the storage of semen collected from genetically different domestic male pigs. The study was aimed at assessing differences in the course of changes in the integrity of cell membranes in spermatozoa produced by males with different degrees of genetic diversity (pure-bred males, two-breed hybrids and multi-breed crosses) and testing the usefulness of two methods of sperm cell membrane integrity evaluation, based on material collected from genetically different males. The experiments were conducted on 56 ejaculates collected from 28 domestic male pigs. The examination of sperm cell membrane integrity was performed three times for each ejaculate, i.e., after 1 h, after 24 h and after 48 h from collection. The preparations for analysing cell membrane integrity were made using two methods: the SYBR 14/PI method and the eosin–nigrosin method. It was found that both SYBR 14/PI and eosin–nigrosin staining methods make it possible to successfully assess the integrity of the plasma membrane of domestic pig sperm cells under in vitro conditions. Hybrid pig spermatozoa, especially those from multi-breed crosses, better retain the integrity of their plasmalemmas than the spermatozoa of pure-bred boars. The ejaculates of Hypor cross-breed boars assessed after 1, 24 and 48 h of storage contain more spermatozoa with intact cell membranes than the ejaculates of pure-bred Duroc and Pietrain boars. The ejaculates of Hypor boars also show fewer decaying spermatozoa than those produced by pure-bred boars.

An efficient method of guinea fowl sperm cryopreservation

France is the only country that practices pedigree selection of guinea fowl for meat production. The increasing risk of line extinction for sanitary or breeding failure reasons makes clear the need for an efficient method of reproductive cell cryopreservation in this species. However, an efficient method of guinea fowl sperm freezing in secured packaging is still lacking. The aim of the present study was to develop such a method. Based on results previously obtained in chickens, different cryoprotectants and freezing/thawing processes were tested and then adapted to guinea fowl. Semen quality was measured by semen viability evaluation and then by fertility measured after intravaginal artificial insemination. The best results (70% fertility with frozen-thawed sperm) were obtained by the use of the permeant cryoprotectant agents dimethyl formamide combined with a freezing rate of 30°C/min. The initial insemination frequency also affected the fertility results: 2 consecutive days of inseminations were needed in the first week to ensure enough filling of the utero-vaginal glands of the guinea fowl hen and thus to get successive fertile eggs. Thereafter, a 2-wk insemination frequency was sufficient. This new method, combining biophysical (cryoprotectant agents, freeze/thaw rate) and zootechnical (artificial insemination frequency) features, is the first cryopreservation method successfully developed in secured packaging for guinea fowl sperm. This method is now available for the practice of gene bank conservation and male reproductive management.

Plumping fluid added to storage medium increases twofold the functional life span of fowl spermatozoa in vitro at 4°C

1. The objective of this study was to examine whether addition of plumping fluid (PF) to Lake's solution (LS) for storage of fowl spermatozoa in vitro at 4°C can prolong survival and improve the quality of spermatozoa. 2. In experiment 1, aliquots of spermatozoa were stored in vitro in LS alone and LS containing 10%, 25%, 50% and 75% (v:v) PF for 0.5, 24, 48, 72, 96 and 120 h at 4°C. After the end of each storage period, spermatozoa were evaluated for their viability, mobility and penetrability. Viability was determined using SYBR-14 and propidium iodide (PI) staining. Mobility was assessed using an Accudenz assay. Penetrability was assessed using spermatozoa-inner perivitelline layer (IPL) interaction assay. 3. In experiment 2, aliquots of spermatozoa were stored in vitro in LS alone and LS containing 25% and 50% (v:v) PF for 0.5, 24, 48 and 72 h at 4°C, and then fertility of the spermatozoa was evaluated using intravaginal artificial insemination (AI) in hens. 4. Storage of spermatozoa in LS alone resulted in loss of viability, mobility, penetrability and fertility within 48 h. In contrast, no loss of viability and penetrability was observed for the spermatozoa stored for 48, 96, 72 and 48 h in LS containing 10%, 25%, 50% and 75% (v:v) PF, respectively. In particular, fertilising capacity was not lost for the spermatozoa stored in the presence of 25% or 50% PF in LS for 48 and 24 h, respectively. 5. In conclusion, these findings demonstrated that in vitro exposure of fowl spermatozoa to PF during hypothermic storage in LS prolonged spermatozoa survival. A 25% (v:v) level of inclusion of PF in LS may be effective for the improvement of viability, penetrability and fertilising ability of the stored spermatozoa.

Maturational changes in the survivability and fertility of fowl sperm during their passage through the male reproductive tract

The objective of this study was to examine whether domestic fowl (Gallus domesticus) sperm undergo maturation in their capacity for survival and fertilization in the male reproductive tract. Sperm collected from the testis, epididymis and the proximal, middle and distal vas deferens were simultaneously stored in vitro in minimum essential medium (MEM) at 39°C for 0, 3 and 6h, and at 4°C for 24 and 48h. Sperm membrane integrity was measured using the dual fluorescent stain SYBR-14/propidium iodide (PI). Aliquots of sperm from the various sites were subjected to artificial insemination (AI) into the uteri of hens to assess the duration of sperm survival in the oviduct and to determine the fertility status of the sperm. Testicular sperm exhibited a very low capacity to survive under in vitro liquid storage conditions, irrespective of the storage temperature used, and in the oviduct, and they had a low ability to fertilize the ovum. On the contrary, sperm from the distal vas deferens had a higher survival rate during in vitro storage periods, a longer life span in the oviduct, and high fertility. Survival and fertilizing capacity of the sperm recovered from the testes increased gradually (P<0.05) from the testes to the distal vas deferens. In conclusion, we suggest that fowl sperm may undergo functional maturation through a process of gradual changes in their survival and fertilization capacities during their passage through the successive parts of the male reproductive tract.

Relationship between sperm quality traits and field-fertility of porcine semen

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 10⁸ sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 10⁶ sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 10⁹ spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity.

Effect of collection frequency on quantitative and qualitative characteristics of pigeon (Columba livia) semen

The aim was to estimate the optimal frequency of semen collection from pigeons in relation to ejaculate volume, sperm concentration, total spermatozoa in ejaculate and percentage of live morphologically normal cells. The study was carried out on 455 ejaculates collected from two groups of pigeons, each of 10 males (group I: meat-type breed; group II: fancy pigeon). The birds were selected and kept individually in cages under a natural photoperiod. A two-person technique was used for semen collection (lumbo-sacral and cloacal region massage). Semen was collected once, twice or three times per week. Colour, consistency and volume of ejaculates were evaluated macroscopically immediately after collection. Sperm concentration and total number of cells in the ejaculate were estimated after dilution with Ringer's solution. A live-dead stain technique (nigrosin-eosin) was used to determine the percentage of live and normal spermatozoa. Semen collected 3x/week was of high quality. The average volume of a single ejaculate was small (21 microl in group I and 19 microl in group II), but sperm concentration was high--1.58 x 10(9)/ml and 1.96 x 10(9)/ml, respectively. The mean number of spermatozoa per ejaculate was 30.48 x 10(6) in group I and 39.49 x 10(6) in group II. An increased percentage of live and normal spermatozoa in semen collected more frequently was also observed. Collecting pigeon semen 3x/week provides spermatozoa in larger amounts and of better quality than less frequent collections (1x/week or 2x/week) and is recommended for obtaining more insemination doses.