Storage of poultry semen

Zinc oxide nanoparticles preserve the quality and fertility potential of rooster sperm during the cryopreservation process

Sperm cryopreservation is one of the main methods for preserving rooster sperm for artificial insemination (AI) in commercial flocks. Yet, rooster sperm is extremely susceptible to reactive oxygen species (ROS) produced during the freezing process. Oxidative stress could be prevented by using nanoparticles containing antioxidants. The present study was conducted to investigate the effect of zinc oxide nanoparticles (ZnONP) in rooster semen freezing extender on quality parameters and fertility potential. For this aim, semen samples were collected and diluted in Lake extenders as follows: control: Lake without ZnONP, ZnO100: Lake with 100-μg zinc oxide (ZnO), ZnONP50: Lake with 50-μg ZnONP, ZnONP100: Lake with 100-μg ZnONP and ZnONP200: Lake with 200-μg ZnONP. After freezing and thawing, sperm motility, viability, membrane integrity, morphology, mitochondrial activity, acrosome integrity, DNA fragmentation, lipid peroxidation and ROS, as well as fertility and hatchability were assessed. According to the current results, higher rates of motility, membrane integrity, mitochondrial activity, acrosome integrity and live cells were detected in the ZnO100, ZnONP50 and ZnONP100 groups compared to other groups (p ≤ .05). Yet, the percentage of dead cells, DNA fragmentation, lipid peroxidation and ROS levels were lower in the mentioned groups (p ≤ .05). Furthermore, a higher percentage of fertility was observed in the ZnO100 and ZnONP100 groups than in the control group (p ≤ .05). In conclusion, the use of 100-μg ZnO and 50- to 100-μg ZnONP represents a valuable and safe additive material that could be used to improve the quality and fertility potential of rooster sperm under cryopreservation conditions.

Selection of Male Donors in Local Chicken Breeds to Implement the Italian Semen Cryobank: Variability in Semen Quality, Freezability and Fertility

Native breed conservation is an important component of poultry biodiversity. The aim of this work is to describe different steps that lead to donor selection for the implementation of the Italian Semen Cryobank of Autochthonous Chicken and Turkey Breeds. The variability within and between breeds was evaluated, and the stored semen reproductive capacity was in vivo tested using artificial insemination. Semen from Bionda Piemontese, Bianca di Saluzzo and Pepoi roosters was collected and processed. Concentration, volume, sperm membrane integrity, total motile sperm, progressive motile sperm and kinetic parameters were analyzed; sperm parameters accounting for bird variability were used to select male donors. Fresh semen quality parameters measured in donor ejaculates showed significant differences between breeds; no differences were found after cryopreservation. Variability in the fertilizing ability of cryopreserved semen was found within a breed (5-16%) and between birds within a breed (BP = 3-7%; BS = 7-31%; PP = 6-22%); only sperm quality parameters measured in fresh ejaculates, not frozen/thawed, may be associated with in vivo fertility results. In conclusion, sperm concentration and progressive motility were successfully used as selection parameters to identify chicken male donors with improved sperm quality for sperm cryobanking. However, new reliable sperm markers to predict cryopreserved semen's fertilizing ability are required.

Liquid semen storage-induced alteration in the protein composition of turkey (Meleagris gallopavo) spermatozoa

Liquid storage of turkey semen without the loss of fertilizing ability is of practical interest to the poultry industry. However, fertility rates from liquid-stored turkey semen decline within a few hours. A clear cause of the decline in spermatozoa quality remains unidentified. Therefore, the purpose of the present study was to monitor the dynamics of proteomic changes in spermatozoa during 48 h of liquid storage by 2-dimensional difference in-gel electrophoresis coupled with matrix-assisted laser desorption/ionization mass spectrometry. A total of 57 protein spots were differentially expressed between fresh and stored spermatozoa; 42 spots were more and 15 were less abundant after 48 h of semen storage. Raw proteomic data are available via ProteomeXchange with identifier PXD043050. The selected differentially expressed proteins (DEPs) were validated by western blotting and localized in specific spermatozoa structures by immunofluorescence, such as the head (acrosin and tubulin α), midpiece (acrosin, aconitate hydratase 2, and glycerol-3-phosphate dehydrogenase) and tail (tubulin α). Most of the DEPs that changed in response to liquid storage were related to flagellum-dependent cell motility, energy derivation through oxidation of organic compounds and induction of fertilization, suggesting the complexity of the processes leading to the decrease in stored semen quality. The damaging effect of liquid storage on spermatozoa flagellum manifested as more microtubule proteins, such as tubulins and tektins, most likely formed by posttranslational modifications, tubulin α relocation from the tail to the sperm head, which appeared after 48 h of semen storage, and decreases in fibrous shelf proteins at the same time. Motility could be affected by dysregulation of Ca2+-binding proteins and disturbances in energy metabolism in spermatozoa flagellum. Regarding sperm mitochondria, DEPs involved in energy derivation through the oxidation of organic compounds indicated disturbances in fatty acid beta oxidation and the tricarboxylic acid cycle as possible reasons for energy deficiency during liquid storage. Disturbances in acrosin and 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta may be involved in rapid declines in the fertility potential of stored turkey spermatozoa. These results showed the complexity of the processes leading to a decrease in stored semen quality and broadened knowledge of the detrimental effects of liquid storage on turkey spermatozoa physiology.

The Effect of Adding Different Levels of Reduced Glutathione to Extender on the Quality of Cooled Ring-Necked Pheasant Semen

Aim: Artificial propagation of ring-necked pheasant through semen preservation is of significance, as this species is facing enormous threats in its natural habitat. Semen preservation inevitably induces oxidative stress, and exogenous antioxidants need to be investigated for the preservation of ring-necked pheasant semen. Therefore, the current study was conducted to investigate the role of glutathione (GSH) in extender on the liquid storage of ring-necked pheasant semen. Materials and Methods: Semen was collected from 10 sexually mature males, evaluated for sperm motility, and pooled. Pooled semen was aliquoted for dilution with Beltsville poultry semen extender (1:5) at 37°C having GSH levels of 0.0 mM (Control), 0.2, 0.4, 0.6, and 0.8 mM. Extended semen was gradually cooled to 4°C and stored in a refrigerator (4°C) for 48 hours. Semen quality, that is, sperm motility, membrane integrity, viability, acrosomal integrity, and DNA integrity, was assessed at 0, 2, 6, 24, and 48 hours. Results: Sperm motility (%), plasma membrane integrity (%), viability (%), and acrosomal integrity (%) were recorded higher (p < 0.05), whereas DNA fragmentation (%) was recorded lower in extender supplemented with 0.4 mM GSH up to 48 hours of storage compared with 0.2, 0.6, and 0.8 mM GSH concentrations and control. Conclusion: It is concluded that 0.4 mM GSH in extender improves sperm quality parameters of ring-necked pheasant during liquid storage up to 48 hours at 4°C.

Arresting calcium-regulated sperm metabolic dynamics enables prolonged fertility in poultry liquid semen storage

The preservation of liquid semen is pivotal for both industrial livestock production and genetic management/conservation of species with sperm that are not highly cryo-tolerant. Nevertheless, with regard to poultry semen, even brief in vitro storage periods can lead to a notable decline in fertility, despite the in vivo capacity to maintain fertility for several weeks when within the hen's sperm storage tubules. For fertility in sperm, intracellular calcium ions ([Ca2+]i) play a key role in signaling towards modifying energy metabolism. While reducing [Ca2+]i has been found to enhance the preservation of sperm fertility in some mammals, the connection between semen fertility and calcium availability in avian sperm has received limited attention. In this study, we demonstrate that the use of extracellular and intracellular calcium chelators in liquid semen extenders, specifically EGTA and EGTA-AM, has distinct effects on prolonging the fertility of chicken sperm. These results were validated through in vivo fertility tests. Mechanistically, the effects observed were linked to coordination of mitochondrial metabolism and ATP catabolism. Despite both calcium chelators inducing hypoxia, they differentially regulated mitochondrial respiration and ATP accumulation. This regulation was closely linked to a bimodal control of dynein ATPase activity; a direct initial activation with reduction in [Ca2+]i, and subsequent suppression by cytoplasmic acidification caused by lactic acid. These findings not only contribute to advancing poultry liquid semen preservation techniques, but also elucidates biologically relevant mechanisms that may underlie storage within the female reproductive tract in birds.

Collection, Handling, and Preservation of Wild Bird Semen: Current Status, Challenges, and Perspectives

Semen preservation is a significant biotechnology used to safeguard the genetic material of birds, especially those with declining populations, through biobanking. However, there are limited reports on the successful chilling or cryopreservation of wild bird semen. In general, these techniques are not yet well-established for several species of wild birds and pose several challenges such as the need for bird handling and training, contamination of semen samples, low volume of semen collected, and inefficient preservation protocols. To address these challenges and improve post-thawing outcomes, new possibilities are being investigated, including alternative collection methods to traditional digital massage, the use of antioxidants and enzymes in the medium for chilling or freezing, storage methods using different straws from the usual pellet, and slower freezing rates. This review aims to discuss the various aspects of applying semen preservation in wild birds to create germplasm banks, highlighting the primary results obtained and the challenges that need to be addressed.

Short-Term Storage of Rooster Ejaculates: Sperm Quality and Bacterial Profile Differences in Selected Commercial Extenders

Bacterial contamination of semen has become an important contributor to the reduced shelf life of insemination doses in the poultry industry, which is why antibiotics (ATBs) are an important component of semen extenders. Due to a global rise in antimicrobial resistance, the aim of this study was to assess the efficiency of selected commercially available semen extenders to prevent possible bacterial contamination of rooster ejaculates. Two selected extenders free from or containing 31.2 µg/mL kanamycin (KAN) were used to process semen samples from 63 healthy Lohmann Brown roosters. Phosphate-buffered saline without ATBs was used as a control. The extended samples were stored at 4 °C for 24 h. Sperm motility, viability, mitochondrial activity, DNA integrity and the oxidative profile of each extended sample were assessed following 2 h and 24 h of storage. Furthermore, selective media were used to quantify the bacterial load and specific bacterial species were identified with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The results indicate that semen extenders enriched with KAN ensured a significantly higher preservation of sperm quality in comparison to their KAN-free counterparts. Bacterial load was significantly decreased in diluents supplemented with ATBs (p ≤ 0.001); however, KAN alone was not effective enough to eradicate all bacteria since several Escherichia coli, Enterococcus faecalis, Enterococcus faecium and Micrococcus luteus were retrieved from samples extended in KAN-supplemented commercial extenders. As such, we may suggest that more focus should be devoted to the selection of an optimal combination and dose of antibiotics for poultry extenders, which should be accompanied by a more frequent bacteriological screening of native as well as extended poultry semen.

Kinetic vitrification: concepts and perspectives in animal sperm cryopreservation

Sperm cryopreservation is an important tool for genetic diversity management programs and the conservation of endangered breeds and species. The most widely used method of sperm conservation is slow freezing, however, during the process, sperm cells suffer from cryoinjury, which reduces their viability and fertility rates. One of the alternatives to slow freezing is vitrification, that consist on rapid freezing, in which viable cells undergo glass-like solidification. This technology requires large concentrations of permeable cryoprotectants (P- CPA's) which increase the viscosity of the medium to prevent intracellular ice formation during cooling and warming, obtaining successful results in vitrification of oocytes and embryos. Unfortunately, this technology failed when applied to vitrification of sperm due to its higher sensitivity to increasing concentrations of P-CPAs. Alternatively, a technique termed 'kinetic sperm vitrification' has been used and consists in a technique of permeant cryoprotectant-free cryopreservation by direct plunging of a sperm suspension into liquid nitrogen. Some of the advantages of kinetic vitrification are the speed of execution and no rate-controlled equipment required. This technique has been used successfully and with better results for motility in human (50-70% motility recovery), dog (42%), fish (82%) and donkey (21.7%). However, more studies are required to improve sperm viability after devitrification, especially when it comes to motility recovery. The objective of this review is to present the principles of kinetic vitrification, the main findings in the literature, and the perspectives for the utilization of this technique as a cryopreservation method.

Polymyxin B neutralizes endotoxin and improves the quality of chicken semen during liquid storage

Despite its importance in gamete utilization for livestock production, poultry semen cryopreservation in a liquid state, is limited in the poultry industry due to a significant decline in sperm viability and functionality during liquid storage. Lipopolysaccharide (LPS) is released from gram-negative bacteria and impairs sperm function in mammals. Using exogeneous LPS, we show this endotoxin compromises sperm viability and function, including motility and penetrability to the inner peri-vitelline layer (IPVL) during liquid storage at 4 °C. This outcome was supported by LPS quantification showing an extreme increase in the first 24 h of storage. Polymyxin B (PMB) is an LPS neutralizer previously shown to improve fertility in boar semen, thus we explored the effect of PMB on chicken semen quality during liquid storage. Sperm viability and penetrability tests showed that PMB completely abolishes the deleterious effect by LPS. However, co-addition of PMB with penicillin G (PenG), an antibiotic against gram positive bacteria, reduces IPVL-penetrability while improving sperm viability post-storage. Furthermore, artificial insemination trials showed that PMB addition improves semen fertility at the post liquid storage. Our results show that chicken semen quality during liquid storage is impaired by bacterial LPS, but improved by PMB addition due to cancelled endotoxic effects, which offers a new approach for prolonged fertility of poultry semen storage in a liquid state.

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.

Factors affecting cryopreservation-associated damages in sperm motility of cockerels (Gallus gallus domesticus)

1. Sperm are exposed to severe osmotic stress during cryopreservation, which results in impairment of fertilisation ability, including motility and viability, in poultry. Sperm osmotolerance is regulated by many extracellular factors and varies widely in birds, leading to uncertainty in the nature of the osmotic injury.2. Tail bending is a primary response resulting from cell swelling from excessive osmotic stress. However, the underlying mechanism responsible for tail bending is largely unknown. This study examined the relationship between osmotic stress and post-thaw motility, with a particular focus on the role of Na⁺/K⁺ ATPase (NKA) in the tail bending response.3. Cryopreserved sperm exhibited rapidly reduced motility when maintained at 37°C. The combination of temperature change and osmotic stress was a primary factor responsible for tail bending. This work tested a hypothesis known to be associated with post-thaw tail abnormality in other species and found that cold shock, that is not accompanied by an apoptotic response, may occur. Ouabain inhibition of Na⁺/K⁺ ATPase activity alleviated the tail bending response in fresh and post-thaw sperm.4. These results demonstrated that the combination of temperature change and osmotic stress has a primary impact on the reduction of post-thaw motility, with a particular role in NKA activity, in the tail bending response of chicken sperm. These results provide a foundation for establishing cryopreservation methodology to ensure the optimal fertilisation potential of cryopreserved chicken sperm.

Methylene blue-mediated antimicrobial photodynamic therapy on chicken semen

BACKGROUND

Artificial insemination is widely employed in poultry, but high degrees of bacterial contamination are often observed in semen because of its passage through the cloaca. Consequently, most semen extenders for birds have antibiotics that could aggravate bacterial resistance.

METHODS

We evaluated the potential of antimicrobial photodynamic therapy (PDT) as an alternative to the use of antibiotics, and assessed whether changes in concentration and incubation time with methylene blue (MB), radiant exposure, and irradiance of light affect spermatozoa activity and bacteria in chicken semen.

RESULTS

Incubation with MB (< 25 µM) did not alter sperm motility, regardless of the pre-irradiation time (PIT, 1 or 5 min). Following 1 min of PIT with MB at 10 µM, samples were irradiated for 30, 60, 120, and 180 s at irradiances of 44, 29, and 17 mW/ cm² (660 nm LedBox). MB and light alone did not interfere with the analyzed parameters. However, when both factors were associated, increases in light dose led to greater reductions in sperm parameters, regardless of the irradiance used. Besides, PDT conditions that were less harmful to spermatozoa were not able to significantly reduce bacterial colonies in chicken semen.

CONCLUSIONS

A failure in MB selectivity could explain unsuccessful bacterial reduction following PDT. Further research involving other photosensitizers or conjugating molecules to MB to target microbial cells is needed for PDT application in poultry breeders.

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.

Determining the Optimal Dosage of Lecithin Nanoliposome in Rooster Semen Freezing Medium and Fertility Potential

Introduction: Lecithin nanoliposome (nano-LPO), with its cryoprotective properties, is considered to enhance the performance of a traditional semen cryoprotectant. Objective: To determine the optimal dose of lecithin nano-LPO added to the rooster semen extender. Materials and Methods: Semen samples collected weekly from eight broiler breeder roosters were mixed and aliquoted into five equal subsamples, during the five successive weeks. The subsamples were then diluted with a semen extender containing 0%, 0.5%, 1%, 1.5%, or 2% of lecithin nano-LPO. Post-thawed semen quality attributes, including sperm motility and velocity parameters, plasma membrane functionality, mitochondrial membrane potential (MMP), apoptosis-like changes, and fertility potential, were evaluated. Results: Total motility and velocity parameters, including curvilinear velocity (VCL), straight-line velocity (VSL), average path velocity μm/s (VAP), straightness (STR), linearity (LIN), lateral head displacement (ALH), and wobble (WOB) were quadratically (p < 0.01) influenced by graded levels of lecithin nano-LPO, such that the highest values were obtained when 1% of lecithin nano-LPO was used. Treatments had no significant effect on plasma membrane functionality; however, MMP (p < 0.08) and percentages of live and dead spermatozoa (p < 0.05) quadratically responded to increasing levels of lecithin nano-LPO, where the best outcome was found when about 1% of lecithin nano-LPO was used in the semen extender. The percentage of apoptotic spermatozoa cubically responded to increasing levels of lecithin nano-LPO (p ≤ 0.07). No significant trend of fertility rate was found in response to addition of lecithin nano-LPO levels. Conclusions: Supplementing an extender with 1.10% of lecithin nano-LPO is shown to be the optimal dose associated with the most improvement in post-thawed rooster sperm velocity measurements.

Assessment of Sperm Viability and Computer-Assisted Motility Analysis in Budgerigars (Melopsittacus undulatus): Effect of Several In Vitro Processing Conditions

In order to preserve endangered psittacine species, more basic and applied research in reproductive biology is required. Assisted reproductive technologies such as artificial insemination play an important role in parrots species conservation programs to overcome the problem of infertile eggs and male infertility. The aim of this study was to define an effective in vitro protocol in order to standardize the sperm quality evaluation in psittacines, studying Melopsittacus undulatus as model species. Semen was collected from twenty adult males by massage technique from May to June. Sperm concentration was measured by the spectrophotometric method. Sperm quality (sperm membrane integrity (SMI), motility, and kinetic parameters) was assessed on fresh semen. Three different experimental protocols were performed to compare the effects of various processing conditions on SMI, motility, and kinetic parameters. In protocol 1, test was performed by Lake extender with three different pH, 7.4 versus 8.2 versus 8.4, and two different equilibration temperatures after dilution of fresh semen (4°C versus 25°C). In protocol 2, two dilution rates of semen after collection were valuated, 1 : 3 versus 1 : 4, as well as three different semen storage temperatures (4°C versus 25°C versus 38°C) before sperm motility analysis with the computer-assisted sperm analysis (CASA). In protocol 3, two different Makler chamber temperatures (38 versus 41°C) during motility analysis were tested. A significant progressive improvement in spermatozoa motility and kinetic parameters was registered with pH 8.4. Progressive motility and all kinetic parameters were higher at 4°C equilibration temperature. Straightness (STR) kinetic parameter was better with 1 : 4 dilution rate. Total motile sperm was higher in 41°C Makler chamber. In this study, for the first time, the effects of different processing protocols on psittacines seminal quality analysis were investigated. Significant differences conditioning the effectiveness of analysis protocols have been described.

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.

Influence of Zinc and Manganese Nanoparticles on Selected Parameters of Turkey Spermatozoa Stored in a Liquid State at 4 °C

The aim of this study was to determine the effect of semen extender supplementation with 25 or 50 μM of zinc nanoparticles (ZnNPs) or manganese nanoparticles (MnNPs) on turkey spermatozoa preserved in a liquid state. Twenty turkey ejaculates were obtained from twenty healthy males. The collected semen was preserved at 4 °C for 48 h with or without NPs. Selected qualitative and quantitative parameters of sperm (motility, plasma membrane activity, mitochondrial membrane potential (MMP) and the percentage of sperm demonstrating NO and SOD activity) were examined after 2, 24 and 48 h of storage. Sperm motility and MMP decreased in semen preserved with ZnNPs at each time point of the analysis. However, all spermatozoa remained viable throughout storage. In contrast, membrane integrity and mitochondria activity (p ≤ 0.05) increased, and the highest SOD activity (p ≤ 0.05) was observed in semen preserved with MnNPs. The addition of MnNPs to the semen extender could potentially improve the parameters of turkey semen during prolonged storage.

Assessing different liquid-storage temperatures for rooster spermatozoa

Although liquid-storage is extensively used in poultry, there are still questions on how sperm physiology is affected and to what extent sperm functions are disrupted by storage temperature and time. There, therefore, was investigation of storage temperature and durations on multiple semen variables. The storage at 37 °C was the most damaging, affecting values for several variables within 4 h of storage, whereas most differences occurred between 5 and 25 °C after 8 h. Progressive motility and mitochondrial function started to decrease within 2 h at 25 and 37 °C, and within 4 h at 5 °C. Acrosomal damage only occurred in samples at 37 °C. Eosin-negrosin staining indicated there was damage to the plasma membrane at 37 °C, however, with use of propidium iodide there were differences between 5 and 25 °C following 24 h. Temperatures of 5 and 25 °C resulted in similar curves for chromatin dispersion although chromatin integrities differed with storage for periods longer than 4 h. At 37 °C, results using both chromatin evaluations indicated there was damage after 2 h of incubation. Oxidative stress at 5 and 25 °C was similar when there was 24 h of storage. Intriguingly, there were no interaction between temperature and storage duration for peroxidized sperm membrane and total peroxidation status. These findings indicated that with a prolonged storage at 5 °C there were not marked changes in chicken spermatozoa, whereas at 25 °C there did not appear to be sperm damage occurring as a result of short-term storage.

A systematic review on the effect of Ginger (Zingiber officinale) on improvement of biological and fertility indices of sperm in laboratory animals, poultry and humans

There is an evidence that ginger enhance semen quality via improving different sperm parameters mainly count, viability, motility, morphology and DNA integrity. According to research results in various species, ginger seems to have strong antioxidant properties (due to the presence of active phenolic compounds) and androgenic activity. Ginger improves semen quality and increases fertility of sperm by disrupting the production of free radicals, dissolving oxidative chain reactions, reducing oxidative stress and altering the levels of gonadotropin hormones (LH, FSH) and sex hormones (such as testosterone). The antioxidant and androgenic properties of ginger give a sperm with normal morphological structure (head, middle and tail) and more integrated chromatin. The rate of DNA failure and damage to the mitochondrial genome in these cells is minimal and they have the most progressive motility, the highest viability and the best fertility. Therefore, the use of the ginger significantly improves the biological parameters of sperm (number, total motility, survival rate and normal morphology) and also increases all specialized fertility indicators of sperm. Tacking account of lacking literature and possibility of toxicity and adverse effect of ginger on vital organ, further clinical trial especially on evaluating the safety and clinical effect must be considered. Also, dose and duration of consumption by monitoring of health indicators and biochemical changes in all species such as human, animal and poultry must be applied.

Optimization of a Protocol for the Cryopreservation of Sperm in Pellets for the Common Pheasant (Phasianus colchicus mongolicus)

The sperm of each avian species and breed have unique characteristics that render them more or less susceptible to the freezing-thawing process; therefore, a suitable cryopreservation protocol that is specific for the sperm of each type of bird is needed. In this context, little information about the common pheasant's sperm is available. Therefore, the aim of this study was to test different parameters at each step of the process of freezing into pellets and thawing to detect the least deleterious parameter settings. Sixteen different protocols were tested by studying two levels in each of the four steps (dilution, equilibration at 5 °C, final dimethylacetamide concentration, and dimethylacetamide equilibration time) comprising the freezing process. The pheasant sperm exhibited a high susceptibility to the damage caused by freezing into pellets; however, the survival of the sperm reached 29%, and the greatest recovered mobility was 22%. The mobility of the sperm was affected by the dilution and the dimethylacetamide concentration, and the viability of the sperm was affected by the equilibration at 5 °C and the dimethylacetamide equilibration. The protocols that caused the least damage to the pheasant sperm were found to be those with higher dilution rates, 10 min of equilibration at 5 °C, and 6% dimethylacetamide equilibrated for 1 or 5 min. In the present study, we individualise some applicable parameters for certain critical steps of the freezing-thawing process; however, further investigations are needed in order to improve upon and complete a suitable protocol for the cryopreservation and thawing of pheasant sperm.

Type III antifreeze protein (AFP) improves the post-thaw quality and in vivo fertility of rooster spermatozoa

Antifreeze proteins (AFP) have the potential for improving sperm cryopreservation. We have applied Type III antifreeze protein (AFP3) on the cryopreservation of spermatozoa from broiler breeder roosters, aiming to enhance post-thawing quality and fertility. Semen was extended at 37°C in Lake's extender containing AFP3 at 0.01, 0.1, 1, 5, and 10 µg/mL (no AFP3 as control). Post-thawing sperm assessment included sperm motility (CASA), morphology, membrane functionality by hypoosmotic swelling test (HOST), lipoperoxidation as malondialdehyde (MDA) production, and sperm viability, early apoptosis (phosphatidylserine exposure as annexin V-positive staining in viable spermatozoa), and mitochondrial activity by flow cytometry. Fertility was assessed after artificial insemination (30 hens/treatment). Total and progressive motility, membrane functionality, and mitochondrial activity increased in 0.1 and 1 µg/mL AFP, compared to control and other concentrations, whereas apoptosis was significantly lower. VAP, VSL, and viability were significantly higher for 1 µg/mL AFP3 than with the other treatments except for 0.1 µg/mL (which was not always significantly different from the control or other concentrations), and with abnormal forms being significantly lower. The proportion of fertilized and hatched eggs was also higher for 1 µg/mL AFP3, with 0.1 µg/mL also showing significantly higher results than the control, and no differences with other concentrations). In conclusion, 1 µg/mL AFP3 could improve the post-thawing results of rooster spermatozoa frozen in Lake's extender. According to our results, concentrations between 1 and 0.1 µg/mL could be similarly efficient.

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.

Interventions in mating strategies of broiler breeder during peak and post peak phase influence hatching traits

The study evaluated the effect of housing system, insemination frequency, and sperm concentration on hatching traits of commercial broiler breeder. Experiment was set up as 2 × 4 × 4 factorial arrangement under completely randomized design. A total of 960 broiler breeder females (Ross-308) were divided evenly (480) into two groups for Artificial Insemination in cages (AIC) and on deep litter floor (AIF) with 41 and 48 males were allocated for aforesaid flocks, respectively. Females birds of both flocks (AIC and AIF) were further divided into 4 treatment groups to apply 4 various insemination frequencies at 4, 6, 8, and 10th days. These treated groups were further divided into 4 subgroups to apply each of insemination frequencies with 4 different sperm concentrations per insemination dose 100, 125, 150, and 175 × 106 sperms during peak phase of production which were replaced with 200, 225, 250, and 275 × 106 sperms in post peak phase. According to the results, significantly higher egg production, fertility, hatchability and number of chicks were documented when AI was conducted in cages as compared to deep litter floor. Although, the best reproductive performance was observed on 4 and 6th day insemination frequencies on all subjected sperm concentrations during peak; however, these parameters were found better on only 4th day during post peak. Sperms concentrations of 150, 175 × 106 during peak and 250 and 275 × 106 during post peak brought forth the best reproductive performance on all insemination frequencies. Although, embryonic mortality was significantly higher, when AI was conducted in floored flocks particularly when repeated after 4th day; however, various sperm concentrations found inert. In conclusion, AI found advantageous in caged flock as compared to floored. The consortium of different insemination frequencies and sperms concentrations are required for sustainable reproductive traits with progression of breeder age.

Beneficial Influence of Soybean Lecithin Nanoparticles on Rooster Frozen-Thawed Semen Quality and Fertility

Simple Summary

Soy lecithin (SL) can be used in to prevent spermatozoa cryodamage during cryopreservation by mitigating the efflux of cholesterol or phospholipids, thus reducing the formation of intracellular ice crystals. SL nanoparticles (nano-SL) have a smaller particle size and higher solubilizing capacity as compared with those that have not undergone nanotreatment. Thus, they allow for a better interaction or coating of sperm, decreasing cold shock injury during freezing–thawing processes. The objective of this study was to determine the optimal concentration of nano-SL. In order to achieve this, we assessed the quality of frozen–thawed semen in vitro and in vivo. We found that a nano-SL dosage of 1.0% in the semen extender had an affirmative influence on post-thawing quality in roosters, improving various parameters related to sperm motion, protecting the membrane and acrosome integrities, increasing mitochondrial activity and antioxidant capacity, and reducing the oxidative stress caused by the cryopreservation process. Moreover, enrichment of 1.0% nano-SL in the semen extender improved the fertilizing capacity of rooster sperm after artificial insemination.

Abstract

The present study aimed to investigate the impact of different concentrations (0%, 0.5%, 1.0%, 1.5%, and 2.0%) of nano-soybean lecithin (SL) in the extender on sperm quality, sperm motion characteristics, and fertility outcomes of post-thawed rooster semen. Adult Ross broiler breeder roosters (n = 20) were subjected to semen collections twice a week for three weeks. At each collection, semen samples were pooled and allocated into five treatments corresponding to different nano-SL concentrations (control, SL0.5, SL1.0, SL1.5, and SL2.0). Sperm parameters, including motility (collected using a computer-assisted sperm analysis system), plasma membrane and acrosome integrities, and mitochondrial activity were assessed. Sperm malondialdehyde (MDA) and antioxidant activities (total antioxidant capacity (TAC); superoxide dismutase (SOD); glutathione peroxidase (GPx)) were evaluated. The fertility and hatchability obtained with frozen–thawed rooster semen supplemented with the optimum nano-SL concentration were assessed after artificial insemination. The results showed that the addition of 1% nano-SL into the extender led to a higher semen motility in roosters, improved plasma membrane and acrosome integrities, and higher mitochondrial activity of post-thawed rooster semen in comparison to controls (p < 0.05). The MDA levels in the SL0.5 and SL1.0 groups were lower than the other groups (p < 0.05). TAC activities in SL0.5, SL1.0, and SL1.5 groups were significantly higher than those in the other groups (p < 0.05). It was observed that the concentration of SOD was higher in the SL1.0 group than in the other groups (p < 0.05). The activity of GPx was not influenced in any of the cases (p > 0.05). Moreover, the percentages of fertility and hatchability in the SL1.0 group were higher (56.36% and 58.06%) than those in the control group (42.72% and 40.43%). In summary, the addition of nano-SL to the extenders enhanced the post-thawed semen quality and fertility of roosters by reducing the level of oxidative stress. The optimum nano-SL concentration was 1.0%. These results may be beneficial for improving the efficacy of semen cryopreservation procedures in poultry breeding.

Cryopreservation of Avian Semen

Cryopreservation protocols for semen exist for bird species used in animal production, fancy and hobby species, and wild bird species. Freezing of bird oocytes or embryos is not possible. Cryopreservation of avian semen is used for preserving (genetic diversity of) endangered species or breeds. Freezing semen can also be used in the breeding industry for maintaining breeding lines, as a cost-effective alternative to holding live birds. Success and efficiency of cryopreservation of bird semen differs among species and breeds or selection lines. This chapter describes important variables of methods for collecting, diluting, cold storage, and freezing and thawing of bird semen, notably the medium composition, cryoprotectant used and its concentration, cooling rate, freezing method, and warming method. Media and methods are described for freezing semen using either glycerol or DMA as cryoprotectant, which both are known in chicken and a number of other bird species to render adequate post-thaw fertility rates.

Effect of crocin and naringenin supplementation in cryopreservation medium on post-thaw rooster sperm quality and expression of apoptosis associated genes

The aim of our study was to examine the effects of crocin (0.5 (C0.5), 1 (C1) and 1.5 (C1.5) mM) and naringenin (50 (N50), 100 (N100) and 150 (N150) μM) in cryopreservation extender for freezing rooster semen. Sperm motility, viability, abnormalities, membrane functionality, active mitochondria, apoptosis status, lipid peroxidation (LP), GPX, SOD, TAC, the mRNA expression of pro-apoptotic (CASPASE 3) and anti-apoptotic (Bcl-2) genes, fertile eggs, hatched eggs and hatching rate were investigated following freeze-thawing. C1 and N100 resulted in higher (P < 0.05) total motility and progressive motility in comparison to the control group. The C1 and N100 groups improved viability, membrane functionality and reduced lipid peroxidation. We found higher values for active mitochondria with C1 and N100 compared to control group. The C1 and N100 groups showed lower percentages of early apoptosis when compared with control group. Also, C1 and N100 had higher TAC, compared to the control group. The mRNA expressions of BCL-2 in the C1 and N100 groups were significantly higher than that of other treatments. The expression of CASPASES 3 was significantly reduced in C1 and N100 group (P < 0.05) when compared to control group. Significantly higher percentages of fertile eggs, hatched eggs and hatching rate were observed in C1 and N100 compared to the control group. In conclusion, crocin at 1 mM and naringenin at 100 μM seem to improve the post-thawing rooster semen quality, fertility and could protect the sperm by reducing the pro-apoptotic (CASPASE 3) and increasing anti-apoptotic (Bcl-2) genes.

Validation of the Turkey Semen Cryopreservation by Evaluating the Effect of Two Diluents and the Inseminating Doses

Simple Summary

Achieving an effective freezing protocol, that is able to preserve the fertilizing ability of turkey semen, is a key aim for the establishment of the first national semen cryobank of autochthonous chicken and turkey breeds within our national project (Tutela della biodiversità nelle razze avicole italiane—TuBAvI). In this regard, we have performed different studies in order to define the best conditions for cryopreservation of turkey semen; namely, we identified an effective freezing protocol which is based on the use of dimethylsulfoxide as a permeant cryoprotectant (CPA) combined with Ficoll as a non-permeant CPA. Here, our purpose was to test this protocol in vivo, by evaluating the effect of two extenders and three inseminating doses. The good fertility and hatching rates achieved here are promising for future studies, in which our cryopreservation protocol will be tested on Italian autochthonous turkey breeds and also to the advantages offered by the extensive use of frozen semen in the turkey breeding industry.

Abstract

This study was designed to test the fertilizing ability of cryopreserved turkey semen, and here, two experiments were performed: an in vitro analysis to assess the effects of Tselutin and Lake diluents and an in vivo test to determine the fertility and hatching rates by also studying the feat of three insemination doses (250, 400 and 600 × 10⁶ sperm/hen). Pooled semen samples were diluted with Tselutin or Lake extender which contained 20% of dimethylsulfoxide and 1 mM of Ficoll at final sperm concentration of 3 × 10⁹ sperm/mL. Thereafter, semen was packaged into straws and frozen on liquid nitrogen. The post-thaw sperm quality was evaluated considering motility (computer-aided sperm analysis—CASA system) and membrane integrity (flow cytometry). Significantly higher values of progressive motility and some kinetic parameters in semen frozen with Lake were found. When we compared the extenders in vivo, no significant effects were detected, whilst sperm concentration significantly affected both fertility and hatching rates, with the best results obtained with the sperm concentration of 400 × 10⁶ sperm/hen. From the results obtained, it emerged that the extender type only affected sperm motility characteristics, not the fertilizing ability of frozen-thawed semen, while inseminating dose markedly affected fertility and hatching rates.

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.

Effect of semen extenders on viability of ISA Brown and Hubbard Flex roosters' sperm stored for 24 h

Artificial insemination is used in almost 95% of turkey reproductive flocks and is becoming more important in chickens, particularly broiler breeders, as well as in assisted reproduction of wild birds kept in breeding centers. Diluted semen is recommended for artificial insemination. Pooled semen samples collected twice a week by dorso-abdominal massage from 2 chicken lines: laying-ISA Brown (ISA-B) and meat type-Hubbard Flex (H-F) were divided into 5 parts: neat semen and diluted in 1:2 ratio with 4 extenders: basic EK; EK + 1 μg/mL organic selenium and 8 μg/mL vitamin E; EK + 10 mg/mL of royal jelly; and EK + 0.25 g/mL of lyophilized bovine colostrum. Diluted semen samples were evaluated after 15 min and then 24 h storage at 4°C. Sperm concentration, motility, motility parameters (with Sperm Class Analyzer), and morphology were evaluated in the neat semen, whereas in diluted and stored samples, the last 3 traits were determined. In case of both lines, dilution did not affect (P > 0.05) the number of live normal cells (78.0-81.1% in ISA Brown and 73.8-68.7% in Hubbard Flex) in relation to neat semen; however, bovine colostrum addition increased (P < 0.05) the percentage of bulb head sperm (5.7 vs. 10.0% and 12.1 vs. 17.6%, for ISA and Hubbard, respectively) and decreased sperm motility (67.4 vs. 92.9% and 67.3 vs. 98.5% for ISA and Hubbard). The 24 h storage of neat semen and semen diluted with colostrum caused (P < 0.05) the unfavorable changes in all evaluated traits and both chicken lines, whereas semen dilution with remaining extenders decreased the percentage of live normal cells (by 18.8-23.4% ISA and by 20.9-25.5% Hubbard) but did not affect sperm motility (81.5-87.6% for ISA and 81.1-96.6% for Hubbard). Sperm motility and motility parameters depended both on the extender and chicken line.

Optimization of Sperm Cryopreservation Protocol for Peregrine Falcon (Falco peregrinus)

Sperm cryopreservation is a complex process that needs to be adapted to wild and domestic avian species to ensure proper efficiency. Because of its accessibility, the peregrine falcon may be used as a good model for studying other raptor species. To find the most optimal cryopreservation protocol for peregrine falcon ejaculates, sperm parameters such as motility, viability, DNA fragmentation, acrosome integrity, and mitochondrial activity were analyzed under different conditions by varying the freezing method (slow freezing in straws vs. ultrarapid freezing in pellets), thawing conditions (37 °C for 30 s vs. 5 °C for 1 min), type of cryoprotectant (DMA vs. DMSO), and concentration of DMSO (4% vs. 8%). Results show that slow cryopreservation in straws yielded greater percentages (p < 0.05) of motile spermatozoa (22.5% ± 4.4% vs. 0.0% ± 4.1%), viable spermatozoa with intact acrosomes (84.6% ± 4.3% vs. 77.4% ± 4.3%), and spermatozoa with active mitochondria (41.0% ± 6.7% vs.12.8% ± 6.7%), compared with those obtained by the ultrarapid freezing in pellets. However, no differences were found between different thawing conditions. Moreover, all sperm motility parameters were greater (p < 0.05) when DMSO was used during freezing compared with DMA, although the use of 3% and 8% DMSO produced similar results. In conclusion, these results represent important progress in the study of falcon semen cryopreservation protocol, highlighting the crucial steps of the process and the most suitable conditions.

A genome-wide single nucleotide polymorphism scan reveals genetic markers associated with fertility rate in Chinese Jing Hong chicken

The function of the sperm storage tubules is directly correlated with the fertility of laying hens. However, little is known about the molecular mechanisms regulating the fertility traits in chicken. To identify genetic markers associated with reproductive traits, we calculated fertility rate at 61 to 69 wk (51 D) of Jing Hong chickens parent generation as the phenotype and the genotype were detected by the chicken 600K Affymetrix Axiom High Density single nucleotide polymorphisms (SNP)-array. The genome-wide association study using 190 Jing Hong hens showed that the 20 SNP in chromosomes 3 and 13 were significantly associated with fertility rate. To verify these results, a total of 1900 Jing Hong laying hens from 2 populations (P1 and P2) were further genotyped by polymerase chain reaction-restriction fragments length polymorphisms method. The association analysis results revealed that 12 polymorphisms (AX-75769978, AX-76582632, AX-75730546, AX-75730496, AX-75730588, AX-76530282, AX-76530329, AX-76529310, AX-75769906, AX-75755394, AX-80813697 and AX-76582809) out of 20 showed highly significant effects (P < 0.0001) on fertility rate in P1, P2 and P1+P2. Six haplotypes (TTAA, TTGG, TTAG, CTAA, CTGG, and CTAG) were inferred based on significant loci (AX-75730546 and AX-76530282) also showed significant association with fertility rate, where haplotype CTAG was shown to be markedly associated with the significantly highest (P < 0.0001) fertility rate (in P1, 86.42 ± 0.59; P2, 85.98 ± 0.59 and P1+P2, 86.16 ± 0.42) followed by other haplotypes for the irrespective of population studied. Collectively, we report for the first time that 12 SNP in the chromosomes 3 and 13 were significantly associated with fertility rate during the later stage of egg production, which could be used as the potential genetic markers that would be able to facilitate in the selection and improvement of fertility rate through chicken breeding.

Supplementation of vitamin A to local chicken diets in tropical environment enhances seminal quality and blood testosterone concentration

There is insufficient information on the role of micronutrient supplementation on the productivity of local breeder cocks in a tropical environment. The target of this research, thus, was to deduce the impact of dietary vitamin A incorporation on semen traits and testosterone concentration of local breeder cocks in a tropical environment. One hundred twenty-eight-matured Nigerian local breeder cocks aged 10-12 months were alloted to 4 groups (n = 32): a control group (A) was fed experimental diet supplemented with vitamin A at 0 IU/kg feed and supplemented groups (B-D) fed commercial poultry diet supplemented with vitamin A at 250, 500 and 750 IU/kg feed for 16 weeks. Every group was replicated 4 times with 16 birds in every a replicate. A quadratic typed optimization function was employed to determine the optimum vitamin A supplementation that statistically improved serum testosterone and semen quality indices in local breeder cocks. Semen profiling and serum testosterone concentration were analysed at week 4 (pre-supplementation period), and thereafter at weeks 4, 8 and 12 (supplementation period). Serum testosterone and semen quality indices at pre-supplementation period were similar (p < 0.05) among the groups. Birds on 500 IU vitamin A/kg diet produced sperm with highest (p < 0.05) active motile cells and normal morphology compared to birds on the other 3 diets. Local breeder cocks fed diets having 500 and 750 IU vitamin A/kg diet produced sperm with lowest (p < 0.05) sluggish motile cells compared with those fed the control diet. Semen pH, volume, sperm concentration (SC), acrosome morphology defects and serum testosterone concentration were not affected by vitamin A supplementation. The result of the quadratic optimization model revealed that sluggish motile sperm (Y = 41.098-10.230x + 0.903x²; r² = 0.943, p = 0.039) and normal sperm morphology (Y = 82.665 + 8.834x - 1.500x²; r² = 0.965, p = 0.001) was optimized (p < 0.05) at 5664 and 2945 IU/kg feed, respectively. However, other parameters estimated were not significantly influenced. It is concluded that vitamin A supplementation enhanced sperm quality in local breeder cocks.

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.

Effect of dimethylacetamide and N-methylacetamide on the quality and fertility of frozen/thawed chicken semen

The aim was to compare the effect of dimethylacetamide (DMA) and N-methylacetamide (NMA) concentrations on the quality and fertility of post-thaw chicken semen. Ejaculates were obtained from 30 Hi-Line White roosters and processed according to the following treatments: lake pre-freezing extender + 0.1 M trehalose (LPF-T) + 6% DMA (control treatment), LPF-T + 9% DMA, LPF-T + 6% NMA, and LPF-T + 9% NMA. Sperm quality (viability, motility, and kinetic traits) was assessed before and after cryopreservation. A total of 15 laying hens per treatment were inseminated to assess fertility and embryo viability. Sperm cryopreserved in presence of DMA had significantly better in vitro quality compared to NMA, showing the highest proportion of viable and progressive motile sperm recovered after thawing. Furthermore, proportion of progressive motile sperm and the VCL, LIN, ALH, and WOB mean values were significantly improved in semen samples frozen/thawed with 6% compared to 9% cryoprotectant concentration. However, the best cryoprotective action on sperm quality played by DMA and the lowest cryoprotectant concentration did not translate into a concomitant advantage in in vivo semen fertility that showed no differences between cryoprotectant and cryoprotectant concentration treatments. Finally, the cryoprotectant DMA and NMA showed an opposite effect on embryo viability in comparison with the effect played on in vitro semen quality, being NMA more efficient than DMA on preserving viable embryos. The present results suggest the urgency to further decrease the cryoprotectant concentration in poultry semen freezing procedures and to assess the specific toxic effect of cryoprotectant on sperm integrity, fertility, and embryo development.

The effect of zinc oxide on rooster semen cryopreservation

1. Deleterious effects from the freeze-thawing process on post-thawed sperm quality attributes are main limiting factors in cryopreservation. The current study was conducted to determine the effect of semen extender containing zinc oxide (ZnO) on post-thaw rooster sperm quality indices.2. Semen samples from six, 60-week-old broiler breeder roosters were collected weekly during five successive weeks. The samples were mixed and divided into three equal parts and diluted with semen extender containing different levels of ZnO; 0 (ZnO-0), 1 (ZnO-1) or 2 (ZnO-2) µg/ml. After thawing, motility and velocity parameters, plasma membrane functionality, apoptotic like changes, mitochondrial membrane potential (MMP), and DNA fragmentation index (DFI) were evaluated.3. Results showed that the addition of ZnO in the extender quadratically affected (P < 0.01) total motility (TM), progressive motility (PM), and average path velocity (VAP) with the highest values were noted in the ZnO-1 group. Levels of ZnO quadratically affected percentages of live (P < 0.01), apoptotic (P < 0.03) and dead (P < 0.10) spermatozoa, where the highest percentage of live, and the lowest percentage of apoptotic or dead spermatozoa was for the ZnO-1 group. Although adding ZnO quadratically affected plasma membrane functionality and MMP (P < 0.01), it did not affect (P > 0.05) DFI.4. In conclusion, there were some beneficial effects of ZnO supplementation in semen extender on post-thawed rooster sperm quality which may result in a better freezability.

Age-related declines in ejaculate quality and sperm kinematics vary among strains of Japanese Quail (Coturnix japonica)

For successful breeding programs, it is important to quantify the useful period of a male's reproductive life and it is often done simply by measurement of semen quality. This information is lacking for Japanese quail so we tested whether there is a decline in ejaculate quality and sperm kinematics with age, and whether the decline varies among strains. Nine males (n = 9) from each of 5 strains (A, B, C, D and E) were subjected to 4 semen collections (n = 16 per male) at 8, 16, 26 and 36 weeks of age. Ejaculate volume, sperm concentration and total sperm per ejaculate were measured, and sperm kinematics were analysed using a Sperm Class Analyser (SCA^® ). There was a significant effect of age for ejaculate volume, total sperm per ejaculate and per cent medium sperm. The effect of the interaction between age and strain was significant for percent progressive motile sperm, percent rapid sperm, velocity curvilinear, velocity straight line, velocity average path, linearity, straightness and beat cross frequency. Ejaculate volume peaked at Week 26 in all strains, while peak values for sperm concentration and total sperm per ejaculate were observed at Week 16 for most strains. There were declines in percent motile sperm, progressive motile sperm and rapid sperm, and in velocity curvilinear velocity, velocity straight line and velocity average path, by Week 16 for most strains. Linearity declined by Week 26 in some strains, and all strains showed a significant decline in beat cross frequency by that age. In conclusion, the ability of CASA to detect age-related changes in sperm kinematics makes it a valuable tool for identifying the best males and thus improving quail flock fertility. It is essential that breeders understand that age affects both sperm production and sperm kinematics, and that the changes vary with strain.

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.

Transfection efficiency and cytotoxicity of polyethyleneimine-coated magnetic iron oxide nanoparticles in rooster sperm cells

Since the morphology of the rooster spermatozoa is different to other animal spermatozoa, the aim of the current study was to investigate the transfection efficiency and cytotoxicity of polyethyleneimine (PEI) coated magnetic iron oxide nanoparticles (MION) on these cells. Liposome/nucleic acid (NA) complexes and PEI-coated MION linked to the labeled oligonucleotides were used. Viability and percentage of exogenous nucleic acid uptake of spermatozoa were measured by flow cytometry analyses. The results showed a significant increase in exogenous nucleic acid uptake by rooster spermatozoa (P < 0.001) when treated with MION-NA complexes in comparison to liposome/NA. There were no significant differences between efficiency of lipid-based transfection agent and MION (P > 0.05) during short incubation period. MION with or without magnetic field, did not show significant cytotoxicity while the lipid-based transfection agent significantly decreased (P < 0.05) the viability of rooster spermatozoa. Results of this study showed that magnetofection and lipofection were both effective methods which increased exogenous nucleic acid uptake by rooster spermatozoa. However, the magnetofection method was more successful in maintaining the cell's survival than lipofection method.

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.