Effects of different extenders on epigenetic patterns and functional parameters of bull sperm during cryopreservation process

The cryopreservation process induces alterations in cellular parameters and epigenetic patterns in bull sperm, which can be prevented by adding cryoprotectants in the freezing extenders. The purpose of this study was to compare the protective effects of two extenders based on soybean lecithin (SLE) and egg yolk (EYE) on epigenetic patterns and quality parameters of sperm such as motility parameters, mitochondrial membrane integrity, DNA fragmentation, viability, and apoptotic-like changes of bull sperm after cryopreservation. Results demonstrated that cryopreservation significantly (p < .05) reduced the level of DNA global methylation, H3K9 histone acetylation, and H3K4 histone methylation in both frozen groups compared to the fresh sperm. Also, the level of H3K9 acetylation was lower in the frozen SLE group (21.2 ± 1.86) compared to EYE group (15.2 ± 1.86). In addition, the SLE frozen group had a higher percentage of viability, progressive motility, and linearity (LIN) in SLE frozen group compared to EYE frozen group. However, no difference was observed in mitochondrial membrane integrity and DNA fragmentation between SLE and EYE frozen groups. While soybean-lecithin-based extender showed some initial positive impacts of epigenetics and semen parameters, further investigations can provide useful information for better freezing.

Protective Effect of N-Acetylcysteine on Rooster Semen Cryopreservation

Cryopreservation of avian semen is a useful reproductive technique in the poultry industry. However, during cooling, elevated reactive oxygen species (ROS) levels have destructive effects on both quality and function of thawed sperm. The aim of the current study is to investigate the antioxidant effects of N-acetylcysteine (NAC) during rooster semen cryopreservation. Semen samples were collected from ten Ross 308 broiler breeder roosters (32 weeks) and mixed. The mixed samples were divided into five equal parts and cryopreserved in Lake Buffer extender that contained different concentrations (0, 0.01, 0.1, 1, and 10 mM) of NAC. The optimum concentration of NAC was determined based on quality parameters of mobility, viability, membrane integrity, acrosome integrity, lipid peroxidation, and mitochondrial membrane potential after the freeze-thaw process. There was a higher percentage (p < 0.05) of total motility (TM) (60.9 ± 2.4%) and progressive motility (PM) (35.6 ± 1.9%) observed with the NAC-0.1 group compared to the other groups. Significantly higher percentages of viability (74.4 ± 2.3% and 71 ± 2.3%), membrane integrity (76.4 ± 1.5% and 74.7 ± 1.5%) and mitochondrial membrane potential (67.1 ± 1.6% and 66.3 ± 1.6%) were observed in the NAC-0.1 and NAC-1 groups compared to the other frozen groups (p < 0.05). The lowest percentage of lipid peroxidation and nonviable sperm was found in the NAC-0.1 and NAC-1 groups compared to the other groups (p < 0.05). The average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), and acrosome integrity, were not affected by different concentrations of NAC in the thawed sperm (p > 0.05). Both NAC-0.1 and NAC-1 appear to be beneficial for maintaining the quality of rooster sperm after thawing.

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.

The effect of peroxisome proliferator-activated receptor gamma (PPARγ) as a mediator of dietary fatty acids and thiazolidinedione in pulmonary arterial hypertension induced by cold stress of broilers

The objective of this experiment was to evaluate the effects of dietary fish oil and pioglitazone as peroxisome proliferators-activated receptor gamma (PPARγ) activating ligands on the reduction of cold-induced ascites in broiler chickens. A total of 480 one-day-old (Ross 308) male chicks were randomly allocated to four treatment groups with eight replicates of 15 birds each. The following treatments were used: 1) ambient temperature (negative control), with basal diet; 2) cold-induced ascites (positive control), with basal diet; 3) cold-induced ascites, with basal diet +10 mg/kg/day pioglitazone and 4) cold-induced ascites, with basal diet +1% of fish oil. When compared with the positive control, body weight gain was higher (P ≤ 0.05) for broilers fed diets containing fish oil and pioglitazone at 28, 42, and 0-42 d. Broilers under cold-induced ascites had the highest blood pressure at 21 and 42 d, while fish oil and pioglitazone treatment reduced the blood pressure (P ≤ 0.05). Red blood cells, white blood cells, hematocrit, erythrocyte osmotic fragility, bursa of Fabricius and spleen weights were improved (P ≤ 0.05) for chickens fed fish oil diets and pioglitazone compared to the cold-induced ascites (positive control). Exposure to cold temperature resulted in an increase in plasma T3 and T3/T4 ratio and decline in plasma T4 (P ≤ 0.05). In conclusion, PPARγ agonist pioglitazone and fish oil as source of omega-3 polyunsaturated fatty acid could be used as a strategy to reduce the negative effects of pulmonary arterial hypertension and ascites in broiler chickens.

Preservation of rooster post-thawed sperm epigenetic modifications, fertility potential and other quality parameters in different extenders using reduced glutathione

Although rooster semen cryopreservation is an efficient procedure to spread qualified semen samples for reproductive goals, some post-thawed qualified semen samples resulted in poor fertility rate that could be related to epigenetic modifications during the cryopreservation process. This research was conducted to investigate the effect of reduced glutathione (GSH) in different cryopreservation extenders (Lake and Beltsville) on preservation of epigenetic modifications, fertility potential and other quality parameters of rooster sperm after thawing. Semen samples were collected and diluted in Lake and Beltsville extenders as follows: L-0: Lake without GSH, L-G: Lake with GSH, B-0: Beltsville without GSH, and B-G: Beltsville with GSH. After freeze-thawing process, sperm motility, membrane functionality, mitochondrial activity, acrosome integrity, viability, apoptosis status, lipid peroxidation, DNA fragmentation, ROS concentration, epigenetic modifications and fertility potential were evaluated. In results, the type of extender had no effect (P > 0.05) of post-thawed sperm quality. The treatments containing GSH presented higher (P ≤ 0.05) total motility, progressive motility, membrane functionality, mitochondrial activity, acrosome integrity, viability, DNA methylation, fertility as well as lower (P ≤ 0.05) lipid peroxidation, apoptosis, DNA fragmentation and ROS concentration than other treatments. Extender supplementation with GSH had no effect (P > 0.05) on histone methylation, histone acetylation and hatching rate. In conclusion, supplementation of rooster sperm cryopreservation extender with GSH could be an effective strategy to preserve post-thawed sperm DNA methylation, fertility and other quality parameters during reproductive programs.

The Effects of Glycerophospholipid Nanomicelles on the Cryotolerance of Frozen-Thawed Rooster Sperm

Semen banking is an efficient method of artificial insemination for commercial breeders. However, the cryopreservation process induces severe damages to plasma membranes, which leads to reduced fertility potential of thawed sperm. The replacement of membrane lipids with oxidized membrane lipids repairs the cell membrane and improves its stability. The aim of this study was to investigate the effects of glycerophospholipid (GPL) nanomicelles on the cryosurvival of thawed rooster semen. Semen samples were collected from six 29-week Ross broiler breeder roosters, then mixed and divided into five equal parts. The samples were diluted with the Beltsville extender containing different concentrations of GPL according to the following groups: 0 (GPL-0), 0.1% (GPL-0.1), 0.5% (GPL-0.5), 1% (GPL-1), and 1.5% (GPL-1.5), then diluted semen was gradually cooled to 4°C during 3 hours and stored in liquid nitrogen. The optimum concentration of GPL was determined based on the quality parameters of thawed sperm. Our results showed sperm exposed to GPL-1 had significantly increased motion parameters and mitochondrial activity. The percentages of viability and membrane integrity were significantly higher in the GPL-1, and GPL-1.5 groups compared with the other groups (p < 0.05). Moreover, the lowest rate of apoptosis and lipid peroxidation were observed in the GPL-1 and GPL-1.5 groups in comparison with the frozen control group. Our findings indicated that membrane lipid replacement with GPL nanomicelles (1% and 1.5%) could substitute for damaged lipids in membranes and protect sperm cells against cryoinjury.

Peroxisome proliferator-activated receptor gamma (PPARγ) activation: a potential treatment for ascites syndrome in broiler chickens

Ascites (serous fluid accumulation in the abdominal cavity) has been observed worldwide in fast growing broilers. Pulmonary vascular remodeling is an important pathological feature of broiler ascites syndrome. Peroxisome proliferators-activated receptor gamma (PPARγ) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) are expressed in pulmonary vascular endothelial cells and vascular smooth muscle cells (VSMC) where they participate in the regulation of normal pulmonary vascular function. The objective of the present study was to investigate the effects of omega-3 fatty acids (found in fish oil) and pioglitazone (PIO) as natural and synthetic PPARγ ligands supplementation on PPARγ and PGC-1α expression in the prevention of pulmonary arterial hypertension (PAH) syndrome in broiler chickens. The experiment was conducted with 4 treatment groups: 1) negative control, normal temperature conditions with basal diet; 2) positive control, low-temperature conditions with basal diet; 3) positive control + 10 mg PIO/kg of weight/d and 4) positive control + 1% FO. Each treatment had 5 replicates. Ascites heart index (RV/TV) was significantly (P < 0.05) reduced in chickens receiving FO (0.20) and PIO (0.21) compared to the positive control group (0.26). The addition of PIO in broilers under cold-induced ascites significantly increased the expression of PPARγ (9.44) and PGC-1α (5.81) genes in lung tissue compared to the negative control group (1.03, P < 0.05). Proliferative indexes of VSMC in pulmonary arteries such as PMT, PIT, and percentage wall thickness were significantly elevated in positive control group, indicating that pulmonary vascular remodeling occurred following VSMC proliferation in ascites. The vessel internal diameter was increased in FO and PIO groups. Based on these results, activation and expression of PPARγ and PGC-1α genes as a critical regulator of pulmonary artery smooth muscle cell using ligands, especially PIO, can be effective in reducing the incidence of PAH in broiler chickens.

Effects of Antifreeze Protein Type I and Glycerol in Diluents on Cryopreserved Goat Epididymal Sperm

The effect of antifreeze protein (AFP) as a cryoprotectant used in different concentrations of glycerol on post-thaw quality of epididymal sperm was investigated. Sperm were isolated from 50 testicles, obtained from 25 healthy mature goat bucks, with progressive motility >80%, and total morphological abnormalities <10% were pooled in each replication. The semen samples were diluted with Tris-citrate-fructose-soybean lecithin extender containing different concentration of AFP [0 μg/mL (A0), 5 μg/mL (A5), 10 μg/mL (A10)]. Each concentration of AFP was added in an extender containing either 7% (G7) or 5% (G5) glycerol. Post-thaw total and progressive motility were found to be higher (p < 0.05) in groups A5G5 and A5G7. Plasma membrane integrity, sperm acrosome integrity, DNA integrity, acrosome intact sperm, and mitochondrial membrane potential were found to be higher (p < 0.05) in groups A5G5 and A10G5. Sperm viability was found to be higher (p < 0.05) in group A5G5, while lipid peroxidation was recorded lower (p < 0.05) in groups A5G5 and A5G7. Regarding the apoptosis occurrence, the results demonstrate higher (p < 0.05) live post-thawed spermatozoa for groups containing 5 μg/mL AFP with 5% and 7% glycerol in addition to the lowest (p < 0.05) value for groups containing 0 μg/mL AFP with 5% and 7% glycerol. Based on these results, the present study concludes that the addition of 5 μg/mL AFP in combination with 5% glycerol in freezing extender improves the post-thaw quality, structure, and function parameters for buck spermatozoa.

Beneficial effects of trehalose and gentiobiose on human sperm cryopreservation

The protection of human sperm during cryopreservation is of great importance to infertility. Recent studies have shown that this area is still a long way from its ultimate aim of maintaining the maximum viability of sperm in cryopreservation. The present study used trehalose and gentiobiose to prepare the human sperm freezing medium during the freezing-thawing. The freezing medium of sperm was prepared with these sugars, and the sperm were then cryopreserved. The viable cells, sperm motility parameters, sperm morphology, membrane integrity, apoptosis, acrosome integrity, DNA fragmentation, mitochondrial membrane potential, reactive oxygen radicals, and malondialdehyde concentration was evaluated using standard protocols. A higher percentage of the total and progressive motility, rate of viable sperm, cell membrane integrity, DNA and acrosome integrity, and mitochondrial membrane potential were observed in the two frozen treatment groups compared to the frozen control. The cells had less abnormal morphology due to treatment with the new freezing medium than the frozen control. The higher malondialdehyde and DNA fragmentation were significantly observed in the two frozen treatment groups than in the frozen control. According to the results of this study, the use of trehalose and gentiobiose in the sperm freezing medium is a suitable strategy for sperm freezing to improve its motion and cellular parameters.

Cryopreservation of Semen in Domestic Animals: A Review of Current Challenges, Applications, and Prospective Strategies

Cryopreservation is a way to preserve germplasm with applications in agriculture, biotechnology, and conservation of endangered animals. Cryopreservation has been available for over a century, yet, using current methods, only around 50% of spermatozoa retain their viability after cryopreservation. This loss is associated with damage to different sperm components including the plasma membrane, nucleus, mitochondria, proteins, mRNAs, and microRNAs. To mitigate this damage, conventional strategies use chemical additives that include classical cryoprotectants such as glycerol, as well as antioxidants, fatty acids, sugars, amino acids, and membrane stabilizers. However, clearly current protocols do not prevent all damage. This may be due to the imperfect function of antioxidants and the probable conversion of media components to more toxic forms during cryopreservation.

Gene expression profile of placentomes and clinical parameters in the cows with retained placenta

BACKGROUND

Retained placenta (RP) is a prevalent disorder in cattle with many health-related and economic costs for the farm owners. Its etiology has not been clarified yet and there is no definite therapy for this disorder. In this study we conducted RNA-seq, hematologic and histologic experiments to survey the causes of RP development.

METHODS

Blood samples were collected from 4 RP and 3 healthy cows during periparturtion period for hematological assessments followed by placentome sampling within 30 min after parturition. Cows were grouped as RP and control in case the placenta was retained or otherwise expelled, respectively. Total RNA was extracted from placentome samples followed by RNA-sequencing.

RESULTS

We showed 240 differentially expressed genes (DEGs) between the RP and control groups. Enrichment analyzes indicated immune system and lipid metabolism as prominent over- and under-represented pathways in RP cows, respectively. Hormonal assessments showed that estradiol-17β (E2) was lower and cortisol tended to be higher in RP cows compared to controls at the day of parturition. Furthermore, histologic experiment showed that villi-crypt junctions remain tighter in RP cows compared to controls and the crypts layer seemed thicker in the placentome of RP cows. Complete blood cell (CBC) parameters were not significantly different between the two groups.

CONCLUSION

Overall, DEGs derived from expression profiling and these genes contributed to enrichment of immune and lipid metabolism pathways. We suggested that E2 could be involved in development of RP and the concentrations of P4 and CBC counts periparturition might not be a determining factor.

Hydroxytyrosol and resveratrol improves kinetic and flow cytometric parameters of cryopreserved bull semen with low cryotolerance

There is considerable interest in breeding programs to "rescue" semen with poor post-thaw fertility from bulls known as "bad freezers". We hypothesized that there may be an interaction between the post-thaw recovery of sperm and the efficacy of antioxidant addition to extenders. The current study assesses the effects of antioxidant additives hydroxytyrosol (HT) and resveratrol (RSV) on the post-thaw semen parameters in two groups of bulls classified as either high or low cryotolerant (i.e., "good" and "bad" freezers). Semen samples were collected from 40 bulls and processed in the extenders containing different concentrations of HT (experiment 1; 0, 25 and 50 µM) and RSV (experiment 2; 0.0, 0.01, 0.1 and 1 mM). In experiment 1, bulls in the low cryotolerance group had a significant improvement in post-thaw recovery at 25 µM and 50 µM (P < 0.05). These improvements were observed in motility and several cellular parameters. However, post-thaw semen quality in the high cryotolerance group was not significantly affected by the HT addition. In experiment 2, although RSV did not have any positive impact in high cryotolerance group, post-thaw recovery in the low cryotolerance bulls was significantly improved in 0.1 mM RSV. Oxidative stress markers in either high or low cryotolerance groups were not significantly changed by RSV addition (P > 0.05). It can be concluded that addition of optimized concentrations of HT and RSV to the extender could be a strategy for improving the post-thaw semen, especially in bulls with high genetic merit but low initial cryotolerance.

Sublethal Xanthine Oxidase Stress Prefreezing of Bull Sperm Improves the Post-Thaw Functionality and Fertility Potential Parameters

Oxidative stress during cryopreservation causes mechanical, biochemical, and structural damage to the sperm, leading to lower viability and fertility potential. In recent years, a novel method based on the use of mild stress for preconditioning of sperm before cryopreservation has been applied to improve the quality of thawed sperm, although its molecular mechanism remains unknown. In this study, we investigated the protective effects of sublethal oxidative stress by xanthine oxidase (XO) on thawed bull sperm performance through modulations of mitochondrial uncoupling protein 2 (UCP2) expression. Semen samples were collected from six bulls, then mixed and divided into four aliquots: frozen control (XO-0) and frozen groups treated with different concentrations of XO, 0.01 μM (XO-0.01), 0.1 μM (XO-0.1), and 1 μM (XO-1). Thawed sperm were evaluated for motion parameters, viability, acrosome integrity, mitochondria activity, membrane integrity, and UCP2 expression. A significant increase of total motility and viability rate was observed in XO-0.1 compared with other frozen groups (p < 0.05). The highest percentage of progressive motility was in XO-0.01 and XO-0.1 compared with other groups (p < 0.05). Moreover, a significantly higher level of sperm mitochondrial membrane potential and membrane integrity was observed in XO-0.1 (p < 0.05). We also found the lowest percentage of sperm mitochondria activity in XO-1 (p < 0.05). In addition, the highest expression of UCP2 was observed in XO-1 (p < 0.05). Our findings suggest that stress preconditioning of bull sperm before cryopreservation can improve thawed sperm functions, which might be mediated through an increase of UCP2 expression.

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.

Sperm flow cytometric parameters, antioxidant status, and testicular histomorphology in roosters fed diets supplemented with camphor

Genetic selection based on the high growth rate and consequently high slaughter weight in broiler chickens has caused many problems in broiler breeders. A negative correlation between growth and reproductive traits has declined semen quality and fertility in roosters. The present study aimed to evaluate the effects of camphor levels on some reproductive parameters included semen parameters, antioxidant status, and testicular development in broiler breeder roosters. Thirty-five ROSS 308 broiler breeder roosters were divided into 5 groups to receive camphor (C) levels: C0, C50, C250, C750, and C1000 ppm for 12 consecutive weeks (31–43 wk). Body weight, seminal volume, sperm concentration, and percentage of live and morphologically normal sperm were not affected by diets (P > 0.05), however, significantly were changed by bird age over the experiment (P < 0.05). Semen quality factor (SQF) significantly was affected by both diets and age (P < 0.05). Mitochondrial activity, apoptotic-like changes, and DNA fragmentation were improved in the groups fed camphor levels compared to the control group (P < 0.05). Testes weight (left, right, and combined weights) and gonadosomatic index were increased linearly by the camphor supplementation (P < 0.05). The serum activity of glutathione peroxidase (GP_X) was not affected by treatments, however, superoxide dismutase (SOD) activity, ferric ion reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were significantly higher in C50, C250, and C750, respectively (P < 0.05). The lower malondialdehyde (MDA) content in the testes and liver samples was observed in C750 (P < 0.05). Excluding the number of Sertoli cells and blood vessels, other histomorphological traits of testes showed one of the linear or quadratic responses to the camphor levels (P < 0.05). It can be concluded that camphor as an antioxidant source may improve reproduction performance in roosters.

Establishment of apiary-level risk of American foulbrood through the detection of Paenibacillus larvae spores in pooled, extracted honey in Saskatchewan

Paenibacillus larvae, the causative agent of American foulbrood (AFB), produces spores that may be detectable within honey. We analyzed the spore content of pooled, extracted honey from 52 large-scale (L) and 64 small-scale (S) Saskatchewan beekeepers over a two-year period (2019–2020). Our objectives were: (i) establish reliable prognostic reference ranges for spore concentrations in extracted honey to determine future AFB risk at the apiary level; (ii) identify management practices as targets for mitigation of risk. P. larvae spores were detected in 753 of 1476 samples (51%). Beekeepers were stratified into low (< 2 spores/gram), moderate (2- < 100 spores/gram), and high (≥ 100 spores/gram) risk categories. Of forty-nine L beekeepers sampled in 2019, those that reported AFB in 2020 included 0/26 low, 3/18 moderate, and 3/5 high risk. Of twenty-seven L beekeepers sampled in 2020, those that reported AFB in 2021 included 0/11 low, 2/14 moderate, and 1/2 high risk. Predictive modelling included indoor overwintering of hives, purchase of used equipment, movement of honey-producing colonies between apiaries, beekeeper demographic, and antimicrobial use as risk category predictors. Saskatchewan beekeepers with fewer than 2 spores/gram in extracted honey that avoid high risk activities may be considered at low risk of AFB the following year.

Comparison of individual hive and apiary-level sample types for spores of Paenibacillus larvae in Saskatchewan honey bee operations

Three commercial honey bee operations in Saskatchewan, Canada, with outbreaks of American foulbrood (AFB) and recent or ongoing metaphylactic antibiotic use were intensively sampled to detect spores of Paenibacillus larvae during the summer of 2019. Here, we compared spore concentrations in different sample types within individual hives, assessed the surrogacy potential of honey collected from honey supers in place of brood chamber honey or adult bees within hives, and evaluated the ability of pooled, extracted honey to predict the degree of spore contamination identified through individual hive testing. Samples of honey and bees from hives within apiaries with a recent, confirmed case of AFB in a single hive (index apiaries) and apiaries without clinical evidence of AFB (unaffected apiaries), as well as pooled, apiary-level honey samples from end-of-season extraction, were collected and cultured to detect and enumerate spores. Only a few hives were heavily contaminated by spores in any given apiary. All operations were different from one another with regard to both the overall degree of spore contamination across apiaries and the distribution of spores between index apiaries and unaffected apiaries. Within operations, individual hive spore concentrations in unaffected apiaries were significantly different from index apiaries in the brood chamber (BC) honey, honey super (HS) honey, and BC bees of one of three operations. Across all operations, BC honey was best for discriminating index apiaries from unaffected apiaries (p = 0.001), followed by HS honey (p = 0.06), and BC bees (p = 0.398). HS honey positively correlated with both BC honey (r_s = 0.76, p < 0.0001) and bees (r_s = 0.50, p < 0.0001) and may be useful as a surrogate for either. Spore concentrations in pooled, extracted honey seem to have predictive potential for overall spore contamination within each operation and may have prognostic value in assessing the risk of future AFB outbreaks at the apiary (or operation) level.

Enhancement of sperm quality and fertility-related parameters in Hubbard grandparent rooster fed diets supplemented with soybean lecithin and vitamin E

The purpose of this study was to investigate the effect of dietary supplementation of different levels of soybean lecithin and vitamin E on semen quality parameters and some reproductive hormones in Hubbard grandparent roosters. The experiment was conducted in a 3 × 2 factorial arrangement with 3 levels of soybean lecithin (0, 1, and 2%) and 2 levels of vitamin E (0 and 300 mg/kg). Semen samples were collected on d 0, 20, 40 and 60 of the experiment and analyzed. Adding 1% soybean lecithin and vitamin E into the diet increased semen volume and sperm concentration, membrane integrity and viability (P < 0.05). Supplementing diets with 1 or 2% lecithin in addition to vitamin E significantly improved total motility and progressive motility (P < 0.05). Vitamin E significantly increased the amplitude of lateral head displacement (ALH) of sperm (P < 0.05). Although there was no effect on LH and FSH when diets were supplemented with vitamin E and 1 or 2% lecithin, testosterone concentration was increased (P < 0.05). Malondialdehyde (MDA) concentration was significantly lower in all 3 treatments containing vitamin E (P < 0.05). It can be concluded that supplementation of rooster diets with vitamin E and 1% lecithin can improve fertility related parameters in Hubbard grandparent roosters.

Modulatory effects of pioglitazone as a ligand for the peroxisome proliferator-activated receptor on semen quality and fertility potential of broiler breeder roosters

Fertility potential in roosters is a crucial topic in broiler breeder reproduction which is thought to be associated with age. This study aims to investigate effects of 2 levels of pioglitazone (PIO) supplementation on peroxisome proliferator-activated receptor gamma (PPAR-γ) expression, semen quality, and fertility parameters of aged broiler breeder roosters. The efficacy of PIO was divided into 2 sections: receptor-dependent and receptor-independent. Expression of PPAR-γ mRNA and protein was assessed in sperm to monitor receptor-dependent actions. Sperm motility, velocity parameters, viability, mitochondrial activity, and apoptosis were assessed for the receptor-independent actions. Broiler breeder roosters were randomly assigned to 3 groups: 1) control received a basal diet (CTRL); 2) PIO-5 received a basal diet supplemented with 5 mg PIO/bird/day, and 3) PIO-10 received a basal diet supplemented with 10 mg PIO/bird/day. In addition, semen samples were collected from 24 Ross broiler breeder roosters at 30, 43, and 53 wk of age. Effects of PIO were significant in terms of total motility, straight-line velocity, mitochondrial activity, and apoptosis (P ≤ 0.05). Total motility, straight-line velocity and mitochondrial activity improved in both PIO groups (P ≤ 0.05) along with a significant reduction in early and late apoptosis in the PIO groups (P ≤ 0.05). Pioglitazone addition affected total motility, mitochondrial activity, early apoptosis and late apoptosis in a linearly and quadratically manner (P < 0.05). PPAR-γ mRNA and protein expression were not significantly upregulated by the different doses of PIO (P > 0.05). Similarly, fertility performance was not significantly changed in the PIO groups (P > 0.05). Moreover, PIO improved mitochondrial activity and decreased the apoptosis rate in the sperm of aged broiler breeder roosters. These improvements were associated with the receptor-independent actions of PIO and the mechanism of action of PIO did not appear to be affected by the PPAR-γ receptor in broiler breeder roosters.

Supplementation of freezing medium with encapsulated or free glutathione during cryopreservation of bull sperm

The objective was to compare effects of encapsulated or free glutathione (GSH) on quality of frozen-thawed bull sperm. Ejaculates were collected via artificial vagina from six mature Holstein bulls once weekly for 6 weeks. All ejaculates had motility ≥70%, sperm concentration ≥1.0 × 10⁹ /mL and ≤15% morphologically abnormal sperm. Each week, semen was pooled and diluted with lecithin-based extenders containing various concentrations of encapsulated (E0, E1, E2.5 and E5 mM) or free (F0, F1, F2.5 and F5 mM) GSH, with total glutathione content determined before and after cryopreservation. Total GSH in fresh semen was (mean+SEM) 4.8 ± 0.2 nmol/10⁸ sperm, whereas in frozen-thawed semen of group F0 (control), it decreased to 1.4 ± 0.2 nmol/10⁸ sperm, a 70.8% reduction (P<0.05). In addition, total GSH in frozen-thawed semen from groups E2.5, E5 and F5 were 2.4 ± 0.2, 2.8 ± 0.2 and 1.8 ± 0.2 nmol/10⁸ sperm, respectively (E5 vs. F0, P<0.05). Compared to group F0, frozen-thawed sperm from group E2.5 had greater (P<0.05) percentages of sperm that were viable (Annexin-V) (61.1 ± 1.8 vs 71.1 ± 1.8) and that had cell membrane integrity (eosin-nigrosin) (64.5 ± 3.1 vs 80.0 ± 3.1). Furthermore, frozen-thawed sperm from group E2.5 had the numerically highest total and progressive motility (CASA) and cell membrane functionality (HOS) and the lowest percentage of early apoptotic sperm (Annexin-V). However, acrosome membrane integrity (PSA) of E5 had the lowest mean (P<0.05), whereas E2.5 caused a small nonsignificant decrease (69.1 ± 1.4%) compared to E0 and F0. In conclusion, 2.5 mM encapsulated GSH in semen extender significantly improved the quality of frozen-thawed bull sperm.

Cysteamine enhances quality and fertility potential of rooster semen in cooled storage

This study investigated the effects of supplementing Lake extender with cysteamine (CYS) on rooster semen quality in cold storage and it's fertility performance. Semen samples were diluted with Lake extender supplemented with different concentrations of CYS (0, 1, 2, 4 and 8 mM) and were cooled and stored at 5 °C for a period of 46 h. Motility, membrane functionality, viability, lipid peroxidation, and mitochondria membrane potential were evaluated at 0, 23 and 46 h of storage. Fertility was assessed at 23 h of storage. Although at the beginning time (0 h), parameters were not affected, 1 mM of CYS improved (P ≤ 0.05) total motility, progressive motility and mitochondria membrane potential during 23 and 46 h storage. Moreover, 1 and 2 mM CYS improved (P ≤ 0.05) membrane functionality and viability compared to other groups. Lipid peroxidation was lower (P ≤ 0.05) in samples diluted with 1 and 2 mM CYS compared to the others. Artificial insemination with 23-hrs cooled-stored semen produced the higher (P ≤ 0.05) fertility rate in groups received 1 and 2 mM CYS compared to the control group. In conclusion, addition of 1 and 2 mM CYS to the extender could be helpful to protect rooster semen against structural and functional damages of cooling storage process.

Underestimated Aspects in Male Infertility: Epigenetics is A New Approach in Men with Obesity or Diabetes: A Review

Infertility is a complex multifactorial problem that affects about 7% of men and 15% of couples worldwide. Many molecular mechanisms involved in male infertility. Destructive effects of infertility on the next generations are not well understood. Approximately 60-75% of male infertility cases have idiopathic causes, and there is a need for additional investigations other than routine examinations. Molecular factors that surround DNA, which are mitotically stable and independently regulate genome activity of DNA sequences, are known as epigenetics. The known epigenetic mechanisms are DNA methylation, histone modifications and non-coding RNAs. Prevalence of metabolic diseases has been increased dramatically because of changes in lifestyle and the current levels of inactivity. Metabolic disorders, such<br />as obesity and diabetes, are prevalent reasons for male infertility; despite the association between metabolic diseases and male infertility, few studies have been conducted on the effects of epigenetic alterations associated with these diseases and sperm abnormalities. Diabetes can affect the reproductive system and testicular function at multiple levels;<br />however, there are very few molecular and epigenetic studies related to sperm from males with diabetes. On the other hand, obesity has similar conditions, while male obesity is linked to notable alterations in the sperm molecular architecture affecting both function and embryo quality. Therefore, in this review article, we presented new and developed technologies to study different patterns of epigenetic changes, and explained the exact mechanisms of epigenetic changes linked to metabolic diseases and their relationship with male infertility.

Rooster frozen-thawed semen quality following sublethal xanthine oxidase treatments

Reactive oxygen species are associated with cryodamage and may be a factor causing or exacerbating cellular cryodamage during freezing and thawing processes. Induction of sublethal oxidative stress as a new approach for preconditioning of sperm improves the cryo-resistance of sperm. The aim of this study was to investigate effects of sublethal concentrations of xanthine oxidase (XO), which induces oxidative stress before cryopreservation on values for semen quality variables of rooster sperm post-thawing. Semen samples were collected from 15 roosters and treated with different concentrations of XO [XO-0, XO-0.005, XO-0.05, XO-0.5, XO-5, and XO-50 U/ml]; then, the effects of treatments with XO as sublethal stressors, were examined. Results indicated the XO-0.5 and XO-5 treatments resulted in a greater percentage of sperm total motility, progressive motility, viability, and membrane functionality compared to other groups. There was no difference after treatments with XO-0, XO-0.005, and XO-0.05 on sperm total motility, membrane functionality, apoptosis, mitochondria activity, and viability. There was a greater percentage of mitochondria activity in sperm of the XO-0.05, XO-0.5, and XO-5 groups. Furthermore, there was the greatest concentration of malondialdehyde (MDA) in samples of the XO-50 group. Values for sperm abnormal morphology, acrosome integrity, and DNA fragmentation were not different among samples post-thawing. Sperm treated with XO-0.5 and XO-5 had a greater fertilization capacity than those of the control group. In conclusion, treatment of sperm with 0.5 and 5 U/ml XO as inducers of mild oxidative stress before cryopreservation, improved several function quality indices of sperm post-thawing.

Preconditioning of bull semen with sub-lethal oxidative stress before cryopreservation: Possible mechanism of mitochondrial uncoupling protein 2

Preconditioning of sperm using sub-lethal oxidative stress before cryopreservation is an innovative approach that can improve sperm cryo-survival. Mitochondrial uncoupling proteins (UCPs) are critical in reducing ROS level during stress conditions. The aim of the current study was to investigate whether mild sub-lethal stress induced by low concentrations of nitric oxide and hydrogen peroxide has a protective effect on quality parameters of post-thaw bull semen through modulations of mitochondrial uncoupling protein 2 (UCP2) expression. Semen samples were collected from 6 mature Holstein bulls, then mixed and divided into 8 aliquots: fresh, frozen control and frozen groups treated with NO: 0.1 (NO-0.1), 1(NO-1), 10 μM (NO-10), and H₂O₂: 0.1(H₂O₂-0.1), 1(H₂O₂-1) and 10μM (H₂O₂-10). A significantly higher percentage of total motility, progressive motility and viability was observed in NO-1 and H₂O₂-10 compared to the other frozen groups (P < 0.05). Sperm exposed to 1 μM NO and 10μM H₂O₂ showed significantly increased percentages of mitochondria activity and membrane integrity (P < 0.05). Moreover, the lowest percentage of apoptotic percentage was observed in the NO-1 and H₂O₂-10 in comparison to the other frozen groups. In addition, the expression level of UCP2 was higher in the NO-1 and H₂O₂-10 compared to the other groups (P < 0.05). It can be concluded that stress preconditioning of bull sperm before cryopreservation can increase UCP2 expression of sperm, that can play a protective role against cryoinjury after thawing.

Proteomics study reveals the molecular mechanisms underlying cryotolerance induced by mild sublethal stress in human sperm

The preconditioning of human sperm with sublethal nitrosative stress before cryopreservation can potentially improve the thawed sperm quality. However, the underlying mechanisms behind this protective strategy are not entirely understood. We compared the cryosurvival of human sperm exposed to 0.01 μM nitric oxide (NO) throughout the cryopreservation and used multiplexed quantitative proteomics approach to identify changes in the proteome profile of preconditioned sperm cells. Semen samples were obtained from 30 normospermia donors and then each sample was divided into three equal parts: fresh (F), frozen-control (C), and frozen exposed to nitric oxide (NO). The sperm undergoing mild sublethal stress showed higher values for motility and viability compared to the frozen control sperm. Moreover, out of 2912 identified proteins, 248 proteins were detected as differentially abundant proteins (DAPs) between cryopreserved groups and fresh group (F) (p < 0.05). Gene ontology (GO) analysis of differentially abundant proteins indicated that the abundance of proteins associated with glycolysis, gluconeogenesis, and fertilization processes was reduced while oxidative phosphorylation pathway was increased in abundance in cryopreserved sperm compared to the fresh sperm. Moreover, redox protein such as thioredoxin 17 was increased in abundance in the NO group compared to the control freezing group. Therefore, the pre-conditioning of sperm prior to cryopreservation may play an important role in maintaining the redox balance in mitochondria of sperm after freezing. Overall, our results indicate that arylsulfatase A (ARSA), serine protease 37 (PRSS37), and sperm surface protein (SP17) may potentially serve as protein biomarkers associated with screening the fertilization potential of the thawed sperm.

Supplementation of Beltsville extender with quercetin improves the quality of frozen-thawed rooster semen

1. Excessive reactive oxygen species (ROS) production during the sperm freeze-thawing process leads to membrane lipid peroxidation, DNA damage, and motility loss.2. This study examined the effect of supplementation of Beltsville poultry semen extender with different concentrations of quercetin (and antioxidants) on the cryopreservation of rooster sperm.3. Semen samples were collected from six Ross broiler breeders via abdominal massage twice a week for 4 weeks (eight replicates), and were divided into five equal aliquots to be diluted in Beltsville extenders that contained different concentrations of quercetin: 0, 5, 10, 15, and 20 mM. Motility, membrane functionality, abnormal morphology, lipid peroxidation, mitochondrial activity, viability, apoptosis status, and fertility potential were assessed post thaw.4. The addition of 10 and 15 mM quercetin to the semen extender significantly increased the total motility, straight-line velocity (VSL), and sperm membrane functionality compared with the other groups (P ≤ 0.05). Moreover, 10 mM quercetin caused higher progressive motility (34.86 ± 3.80%), curvilinear velocity (VCL; 175.11 ± 3.20 µm/s), average path velocity (VAP; 44.35 ± 11.06 µm/s), viability (59.14 ± 1.36%), mitochondrial activity (80.14 ± 2.07%), lower abnormal morphology (19.21 ± 0.45%), and lower lipid peroxidation (2.7 ± 0.13 nmol/ml) compared with the other groups (P < 0.05). The rate of fertility and hatchability after artificial insemination was not affected by experimental groups.5. In conclusion, supplementation of Beltsville extender with 10 mM quercetin could be a suitable method to improve post-thawed rooster sperm quality resulting in better freeze/thaw characteristics.

Sperm Associated Antigens: Vigorous Influencers in Life

Sperm associated antigens (SPAGs) are specific proteins in terms of performance and evolution, that have common expressions in the testes or sperm cells. Moreover, the humoral immune response against some of SPAGs can result in immunological infertilities. On the other hand, recent studies have explored several new properties of SPAGs and shed light on sperm's function, the impact of anti-sperm antibodies (ASA) in immunological infertility, and some tumors related to SPAGs. This article presents an exhaustive review of SPAGs and their roles in the cell cycle, signaling pathways, fertility, sperm-oocyte cross-talk as well as their unfavorable positions as prognostic factors in many types of cancers.

Improving the post-thaw quality of rooster semen using the extender supplemented with resveratrol

Avian spermatozoa are highly susceptible to reactive oxygen species (ROS) produced during the cryopreservation. The aim of the current study was to investigate the antioxidant effects of resveratrol (RSV) during rooster semen cryopreservation. Changes in expression of AMP-activated protein kinase as a possible mechanism behind the beneficial effects of resveratrol were also evaluated. Semen samples were collected from ten Ross broiler breeders (52-wk) using abdominal massage, then divided into 4 equal aliquots and cryopreserved in Beltsville extender that contained different concentrations (0 µM, 0.01µM, 0.1µM, and 1µM) of RSV. higher percentage (P < 0.05) of total motility and membrane integrity was observed in RSV-0.1 compared to the other frozen groups. Moreover, higher percentage of sperm mitochondrial activity was observed in the RSV-0.01 and RSV-0.1 compared to the frozen control (P < 0.05). The lowest percentage of apoptotic like changes was found in the RSV-0.1 in comparison to the other groups (P < 0.05). RSV-0.01 and RSV-1 groups produced the lowest levels of H2O2 and O2- compared to the other frozen groups, respectively. Malondialdehyde (MDA) concentration, velocity average path (VAP), and linearity (LIN) were not affected by different concentrations of RSV (P > 0.05). We observed a dose-dependent increase in AMP-activated protein kinase expression in groups exposed to RSV. Thus, RSV-1 increased AMP-activated protein kinase phosphorylation but had no positive effects on post thaw sperm parameters. Our findings suggest that RSV-0.1 improve thawed sperm functions, and these effects might be mediated through activation of AMP-activated protein kinase.

Protective Effect of Cerium Oxide Nanoparticles on Human Sperm Function During Cryopreservation

The generation of reactive oxygen species during cryopreservation of human sperm has negative effects on the consistency of the thawed sperm. The antioxidant properties of cerium oxide nanoparticles (CeO₂NPs) may be useful for reducing cryodamage in thawed sperm. This research was conducted to determine the effects of CeO₂NPs on the quality and function of human sperm after thawing. Samples of semen obtained from 20 normozoospermic individuals were allocated to the following four groups: fresh, frozen control (sperm not treated with CeO₂NPs), and those exposed to 0.1 μg/mL CeO₂NPs (CeO₂-0.1), 1 μg/mL CeO₂NPs (CeO₂-1), and 5 μg/mL CeO₂NPs (CeO₂-5). Sperm parameters of motility, viability, membrane integrity, DNA fragmentation, protamination, malondialdehyde (MDA) levels, mitochondria membrane potential, and morphology were evaluated after the freezing-thawing process. The results showed that 0.1 μg/mL CeO₂NPs significantly (p < 0.05) improved the following human sperm parameters after thawing: progressive (44.6% ± 1.14% vs. 36.2% ± 1.24%) and total motility (60.9% ± 2.5% vs. 51.3% ± 2.5%), viability (67.9% ± 1.5% vs. 58.1% ± 1.5%), membrane functionality (66.1% ± 1.85% vs. 55.4% ± 1.85%), DNA integrity (30.8% vs. 24.04%), and protamination (69.85% ± 2.09% vs. 57.2% ± 2.09%) compared with the frozen control group. We observed the lowest MDA levels in the CeO₂-0.1 (3.06 ± 0.25 nmol/mL), CeO₂-1 (3.1 ± 0.25 nmol/mL), and CeO₂-5 (3.08 ± 0.25 nmol/mL) groups compared with the frozen control group (3.72 ± 0.25). Different concentrations of CeO₂NPs did not significantly change sperm normal morphology and mitochondria activity (p < 0.05).

Gene Expression Alteration of Sperm-Associated Antigens in Human Cryopreserved Sperm

Background: Sperm-associated antigens (SPAGs) are 18 types of proteins, some of which play important roles in various biological functions associated with assisted reproductive technology outcomes, and are consequently important to the success of fertility programs. Despite the favorable outcomes of fecundity rates among male patients with cancer using cryopreserved sperm, the detrimental impact of freezing on cells has been noted in many studies. Cryopreservation has been thought to have adverse effects on sperm quality through disruptions in the expressions of SPAG genes. This study aimed to evaluate the effects of cryopreservation on the expressions of SPAGs genes and their transcriptome alterations in human sperm. Materials and Methods: A total of 12 normal ejaculations were prepared using the density gradient centrifugation procedure, and the motile sperm fractions were divided into fresh and frozen groups. In the latter, sperm samples were mixed with SpermFreeze^® solution as the cryoprotectant. The cryovial of sperm suspension was first held just over nitrogen vapor and then dipped inside liquid nitrogen. After 3 days, the specimens were thawed in tap water and incubated for 2 hours for recovery. Then, RNA from sperm was extracted for SPAG gene expression analysis, using real-time polymerase chain reaction. Results: Our findings showed a decrease in expression of SPAG5 (p-value = 0.009), SPAG7 (p-value = 0.004), and SPAG12 (SNU13/NHP2L1; p-value = 0.039) genes during cryopreservation. Discussion: The results indicate that the freezing procedure could negatively affect gene expression and to some extent proteins in human spermatozoa. Conclusion: The alteration of SPAG expression could provide new information on the molecular correlation between cryopreservation and increased failure in intracytoplasmic sperm injection and in vitro fertilization.

Membrane lipid replacement with nano-micelles in human sperm cryopreservation improves post-thaw function and acrosome protein integrity

RESEARCH QUESTION

Membrane lipid replacement (MLR) of oxidized membrane lipids can restore sperm cellular membrane functionality and help improve surface protein stability during cryopreservation. What are the effects of MLR with nano-micelles made from a glycerophospholipid (GPL) mixture and cholesterol-loaded cyclodextrin (CLC), on the cryosurvival and expression of acrosome-related proteins in thawed human spermatozoa?

DESIGN

Twenty samples were used to determine the optimum level of nano-micelles by incubation of semen with different concentrations of GPL (0.1 and 1%) and CLC (1 and 2 mg/ml) (including GPL-0.1, GPL-1, CLC-1, CLC-2, CLC-1/GPL-0.1, CLC-2/GPL-0.1, CLC-1/GPL-1 and CLC-2/GPL-1) before cryopreservation. Then, 30 semen samples were collected, and each sample was divided into the following three aliquots: fresh, frozen control and frozen incubated with optimum level of nano-micelles (0.1% GPL and 1 mg/ml CLC).

RESULTS

CLC-1/GPL-0.1 and GPL-0.1 significantly increased motility parameters. CLC-1, GPL-0.1 and CLC-1/GPL-0.1 significantly improved viability rate compared with frozen control group. Significantly higher mitochondrial activity and acrosome integrity, and a lower rate of apoptosis, were observed in the CLC-1/GPL-0.1 compared with the frozen control group. The expression ratios of arylsulfatase A (ARSA), serine protease 37 (PRSS37), serine protease inhibitor Kazal-type 2 (SPINK2) and equatorin (EQTN) significantly increased compared with the frozen control group.

CONCLUSIONS

Modification of membrane cholesterol and GPL mixtures in spermatozoa enhances their acrosome protein integrity by inhibiting early apoptotic changes and spontaneous acrosome reactions.

Effects of dietary L-carnitine on puberty indices in the young breeder rooster

The aim of current study was to investigate the effect of dietary L-Carnitine (LC) in immature roosters on reproductive hormones, lipid profile and testicular histology at the time of maturity. Eighteen 12-wk-old breeder roosters (Ross 308) of similar weights were randomly allocated into 3 dietary treatments (LC-0: basic diet, LC-250: basic diet + 250 mg LC/kg of diet, LC-500: basic diet + 500 mg of LC/kg of diet) in 6 replicates. The feeding program and photoperiod regimen were performed based on ROSS 308 management handbook. Dietary LC supplementation markedly improved testicle weight and testicle index (p < 0.05). Comb height was also affected by LC supplementation (p < 0.05). The testicle weight and index, comb height, and shank lengths improved linearly with increasing levels of dietary LC (p < 0.05). The LC-250 and LC-500 diets significantly improved the number of sertoli cells (NSC), height epithelium seminiferous tubules (HEST), seminiferous tubules diameter (STD), spermiogenesis index (SI) and tubular differentiation index (TDI) of rooster's testis tissue (p < 0.05). The number of seminiferous tubules (NST) was affected by of the amount of LC (p < 0.05). The roosters on the LC-250 mg/kg diet had longer HEST compared to roosters that received the LC-500 mg/kg diet (p < 0.05). Testicular histology parameters increased in a linear and quadratic manner in response to increasing levels of LC (p < 0.05). Dietary LC significantly increased (p < 0.05) plasma concentrations of testosterone, GnRH, LH, FSH and High-Density Lipoprotein (HDL), but reduced the plasma concentration of Low-Density Lipoprotein (LDL). However, no significant differences were observed between LC-250 and LC-500 groups in these parameters. Plasma testosterone, GnRH, LH, LDL and HDL were affected in a linear and quadratic manner in response to increasing levels of LC (p < 0.05). Similarly, FSH increased linearly with increasing dietary LC (p < 0.05). Thus, adding up to 250g of LC per kg of the rooster chicken can improve reproductive hormones, blood lipids and testicular histology parameters at the time of maturity.

The effect of methyl-beta-cyclodextrin on DNA absorption and quality of posttransfected sperm

Sperm can be selected as a natural vector for the production of transgenic animals. Methyl-beta-cyclodextrin (MBCD) removes cholesterol from the phospholipid membrane of sperm and improves the efficiency of DNA uptake by sperm. In experiment 1, fresh sperm was treated with various concentrations of MBCD. The direct effects of MBCD on sperm parameters were monitored. In experiment 2, different concentrations of MBCD (0, 1, 2, and 4 mmol) were assessed for the transfection of genetically exogenous construction to rooster sperm. Washed semen was divided into 5 equal groups for the incubation and transfection with a pcDNA3.1+/hG-CSF vector (exogenous DNA) as follows; Treatment I-Control (washed semen without DNA); Treatment II-Control (washed semen with DNA); Treatment III-(washed semen incubated with DNA and 1 mmol MBCD); Treatment IV-(washed semen incubated with DNA and 2 mmol MBCD); and Treatment V-(washed semen incubated with DNA and 4 mmol MBCD). We demonstrated that rooster spermatozoa spontaneously can uptake exogenous DNA; this was assessed using exogenous DNA amplification (sperm genomic DNA used as a template for PCR reaction) after DNase I treatment. In addition, total motility (TM), progressive motility (PM), velocity parameters [curvilinear velocity (VCL), straight linear velocity (VSL), sperm track straightness (STR), linearity (LIN)], membrane integrity (MI), and membrane functionality were posttransfectionally evaluated. The concentrations of 1 and 2 mmol MBCD significantly (P < 0.05) improved the motion characteristics and membrane integrity of fresh sperm. The presence of hG-CSF in rooster sperm was detected by PCR and based on sperm analyses MBCD (1 mmol) improved the percentage of motility (98.9 ± 0.81), membrane functionality (64 ± 1.64), and MI (76.2 ± 1.65) after transfection when compared with the other groups (P < 0.05). For the production of transgenic chicken, hens were inseminated (AI) by transfected sperm treated with 1 and 0 mmol MBCD. A PCR analysis of the blood samples and dead embryo tissues of chicks did not reveal the transgene integration.

Effects of freezing extender supplementation with mitochondria-targeted antioxidant Mito-TEMPO on frozen-thawed rooster semen quality and reproductive performance

Rooster semen cryopreservation is a useful method to utilize semen samples for artificial insemination in commercial flocks, but with use of the freezing-thawing process there is a reduction in the quality and fertilization capacity of rooster spermatozoa post-thawing. The aim of the current study was to investigate the efficacy of the mitochondria-targeted antioxidant Mito-TEMPO on rooster sperm quality and fertilization capacity after conducting the freezing-thawing processes. Semen samples were diluted and there were five equal aliquots supplemented with 0, 0.5, 5, 50 and 500 μM Mito-TEMPO. Semen samples were subsequently cryopreserved in liquid nitrogen. After thawing, sperm motility, lipid peroxidation, membrane functionality, normal morphology, mitochondria active potential, acrosome integrity, viability, apoptotic-like changes, DNA fragmentation, hydrogen peroxide concentration and fertilizing capacity were evaluated. Supplementation of Lake medium with 5 and 50 μM Mito-TEMPO resulted in greater (P ≤ 0.05) total sperm motility, progressive motility, average path velocity, membrane functionality, mitochondria active potential, acrosome integrity and viability compared with semen of the other groups. Lipid peroxidation, late apoptotic-like changes, DNA fragmentation and hydrogen peroxide content, however, were less (P ≤0.05) in semen samples supplemented with 5 and 50 μM Mito-TEMPO compared to other groups. Furthermore, fertility percentages were greater when there was supplementation with 5 and 50 μM Mito-TEMPO compared to the control group. Mitochondria-targeted antioxidant Mito-TEMPO could be included in semen extender before cryopreservation to improve quality and fertilization capacity of rooster semen after thawing of cryopreserved samples.

Dietary L-carnitine affects the expression of genes involved in apoptosis and fatty acid metabolism in rooster testes

Thirty-six 12-week-old breeder roosters (Ross 308) were randomly allocated into three groups to receive L-carnitine (LC): LC-0, LC-250 or LC-500 mg/kg of diet to evaluate the effects of dietary LC on the expression of apoptotic-related genes and desaturases and elongase mRNA transcript levels, in the cockerel testicles. Alteration of Bak (Bcl2 antagonist/killer), Bcl2, Cas3, Cas8, Cas9, Elovl2, Elovl4, Elovl5, Fads1, Fads2 and Scd expression at 24 and 34 weeks of age was compared by real-time quantitative PCR. The expression of Bcl2 and Elovl5 was significantly up-regulated (p < .05), while Cas8 expression (p < .05) and Bak/Bcl2 ratio were reduced (p < .02) in the cockerel testicles at 24 weeks of age. Although Bak mRNA abundance decreased by dietary LC, Bak/Bcl2 ratio was not affected by the treatments at 34 weeks of age. The expression of Cas3 was down-regulated, while Fads2 was up-regulated in the cockerel testicles by dietary LC at 34 weeks of age (p < .05). The results demonstrate the beneficial effects of LC supplementation in suppression of the Bak/Bcl2 ratio by altering Bak and Bcl2 mRNA abundance and, ultimately, prevention of apoptosis. Furthermore, LC increased the expression of Elovl5 and Fads2 genes which are involved in the metabolism of long chain fatty acids.

Manipulation of fatty acid profiles in roosters' testes, alteration in sexual hormones, improvements in testicular histology characteristics and elevation sperm quality factor by L-carnitine

The present study was designed to investigate the effects of different levels of l-carnitine (LC) on sperm quality factor (SQF), alterations in testis fatty acid profiles, testicular histology and reproductive hormones in young roosters. Eighteen broiler breeders (Ross 308) weighed at 3 months of age. They were randomly classified while each group had six birds. There were three experimental groups based on the LC concentrations (i.e. LC-0, LC-250, LC-500 mg per kg of diet). After two weeks of adaptation, semen samples were collected and evaluated for seminal attributes every two weeks (from week 24 to week 34). At the end of the experiments, four roosters from each treatment group were sacrificed in order to analyze testicular histology, testis fatty acid profiles and reproductive hormones. Supplementing the diet with two of the LC levels for 22 weeks caused significant rise in sperm concentration, viability and SQF compared to that of the control group (P < 0.05). Quadratic analysis in terms of number of seminiferous tubules and spermatogenesis index were significant (P<0.05). Tubular differentiation index improved linearly by the increasing levels of LC supplementation (P<0.01). The analysis of fatty acid profiles showed that LC significantly (P < 0.05) reduced the percentages of C14:0, C21:0, total saturated fatty acids, total odd-chain fatty acids and n-6/n-3 ratio. Moreover, LC significantly increased the percentage of C20:5n-3 (Eicosapentaenoic acid; EPA) (P < 0.05). Analysis of the correlation coefficient revealed that the SQF is in consistency with EPA (r = 0.98; P < 0.04). In contrast, SQF negatively and significantly correlates with odd-chain fatty acids (r = - 0.99; P < 0.001). The desaturation index for C16 fatty acids (16:1cis/C16:0) negligibly increased linearly as LC was added to the diet (P < 0.05). Furthermore, LC caused the roosters to have significant (P < 0.05) high levels of total testosterone and FSH concentrations. The concentration of LH in different treatment groups, however, turned out to be similar in response to the different levels of LC. In conclusion, long-term supplementation of rooster diet with LC can have beneficial effects on SQF and testis histology. The benefits include alterations in testicular histology, reproductive hormones and testicular fatty acid profiles.

Peroxisome proliferator-activated receptors (PPARs) as a mediator of dietary fatty acids affects reproductive performance in broiler breeder roosters

This study analyzed the effects of dietary sources of omega-3 and omega-6 fatty acids on semen parameters and fertility potential in broiler breeder roosters. The mRNA and protein profiles of peroxisome proliferator-activated receptors-γ (PPAR-γ) expression in sperm as potential mediator of FAs were considered. Roosters were categorized into three groups and received their diets for 24 weeks as follows: 1) control diet received a basal diet (CTRL); 2) Fish oil based diet (FO) received the basal diet supplemented with 15 g/kg of diet fish oil; and 3) sunflower oil based diet (SO) received the basal diet supplemented with 15 g/kg of diet sunflower oil. While the different diets had significant effects on semen parameters, the effect of sampling time was not significant. The effect of the diets on sperm parameters were significantly higher in the SO and FO groups in total motility, progressive motility, amplitude of lateral head displacement, linearity, straightness, wobble and viability (P ≤ 0.05). Fertility rate was significantly improved in the FO and SO groups (P = 0001). The highest value for PPAR-γ mRNA was observed in the SO group compared to other groups (P ≤ 0.05). Moreover, supplementation of the roosters' diets with FO and SO increased PPAR-γ protein expression compared to the control. It seems that PPAR-γ could be a strong potential mediator of the underlying mechanism of improvement in semen parameters and reproductive performance of roosters under the effects of both dietary omega-3 and omega-6 polyunsaturated fatty acids.

The mitochondria-targeted antioxidant Mito-TEMPO conserves rooster's cooled semen quality and fertility potential

The PUFAs content of rooster sperm cells makes them vulnerable to the thermal shocks during chilling storage, which reduces the fertility performance of cooled sperm. Extender supplementation with antioxidants is a reasonable method to conserve sperm fertility potential during cooling storage process. The aim of this study was to determine the effect of Mito-TEMPO addition to the Lake medium on rooster sperm quality and fertility potential during cooling process. Semen samples were diluted in the Lake medium and assigned into five equal aliquots and supplemented with 0, 0.5, 5, 50 and 500 μM Mito-TEMPO. Then, the samples were cooled at 5 °C and conserved up to 50 h. Total motility, progressive motility, morphology, viability, membrane integrity, lipid peroxidation and mitochondrial activity of samples were analyzed during 0, 25 and 50 h of cooling period. Artificial insemination was also conducted using 25 h-cooled semen. No significant difference was observed among different treatments during quality evaluations at 0 h storage. Extender supplementation with 5 and 50 μM Mito-TEMPO presented greater (P ≤ 0.05) total motility, progressive motility, viability, membrane integrity and lower lipid peroxidation compared to other groups during 25 and 50 h cooling storage. Mitochondrial activity was higher (P ≤ 0.05) in groups received 5, 50 and 500 μM Mito-TEMPO than others. Fertility rate of 25 h-cooled-stored samples was higher (P ≤ 0.05) in groups containing 5 and 50 μM Mito-TEMPO compared to control group. In conclusion, addition of 5 and 50 μM Mito-TEMPO as a mitochondria-targeted antioxidant to the storage medium could be a suitable method to conserve rooster semen quality against stressful conditions of cooling storage process.

Effect of Glutathione Supplementation to Semen Extender on Post-thawed Rooster Sperm Quality Indices Frozen After Different Equilibration Times

BACKGROUND

Avian sperm is susceptible to lipid peroxidation, compromising their fertility. The semen antioxidant system protects sperm plasma membrane against reactive oxygen species.

OBJECTIVE

The study evaluates the effect of glutathione (GSH) addition to semen extender during different equilibration times (ET) on rooster sperm cryopreservation.

MATERIALS AND METHODS

Semen samples are weekly collected from 60-week-old broiler breeder roosters. Collected samples were pooled and divided to six equal parts and frozen according to a randomized design (2 × 3 factorial arrangement). Treatments included adding two levels of GSH [0 (GSH-0) or 1 (GSH-1) mM] to semen extender during three ET: 0 (ET-0), 4 (ET-4) or 8 (ET-8) hours. Post-thawed motility and velocity parameters, apoptotic like changes, plasma membrane functionality, and mitochondrial membrane potential (MMP) were evaluated.

RESULTS

Post-thawed total motility is improved in the GSH-1 compared to the GSH-0 group (P<0.10). Total motility responded quadratically to increasing levels of ET such that the highest value is recorded at ET-0. Although progressive motility (PM) is not affected by GSH or ET, the highest PM is obtained in the GSH-1×ET-0 group (P<0.05). The VAP and STR is improved in the GSH-1 compared to GSH-0 group; however, VAP decreases quadratically, and STR decreases linearly as ET is advanced (P<0.05). The interactive effect of GSH by ET tends (P<0.08) to affect the wobble coefficient (WOB), such that the highest value is recorded in the GSH-1×ET-0 group. Within both GSH supplemented and control groups, the amplitude of lateral head displacement (ALH) is highest (P<0.05) in the ET-0 group. The percentage of live spermatozoa quadratically decreases and the percentage of dead sperm quadratically increases in response to graded levels of ET (P<0.01). The highest plasma membrane functionality is also noted in the GSH-1×ET-0 group (P<0.05). Mitochondrial membrane potential quadratically decreases in response to increasing levels of ET (P<0.05).

CONCLUSION

Generally, GSH supplementation to rooster sperm extender has some beneficial effects on post-thawed sperm motion characteristics, but does not positively interact with ET.

Inclusion of ovine enriched serum with vitamin E and polyunsaturated fatty acids in the freezing medium: a new strategy to improve human frozen-thawed sperm parameters

The objective was to evaluate the effect of inclusion of 2.5% and 5% ovine serum, enriched with vitamin E (Vit E) and fish oil (FO), in human sperm freezing medium. Serum samples were prepared from sixteen rams (n = 4) feeding on a without supplemented diet, and diets supplemented with Vit E, FO and Vit E + FO. Semen samples, from 60 normozoospermic men, were frozen in: (I) a commercial freezing medium (SpermFreeze™; control medium), (II) the commercial freezing medium containing foetal bovine serum, (III) the commercial freezing medium + nonenriched serum (serum group), (IV) the commercial freezing medium + Vit E enriched serum (Vit E group), (V) the commercial freezing medium + FO enriched serum (FO group) and (VI) the commercial freezing medium + Vit E + FO enriched serum (Vit E + FO group). Sperm total and progressive motility, morphology, viability and plasma membrane integrity were significantly higher (p ≤ .05) in Vit E and Vit E + FO groups compared with the control group. Mitochondrial membrane potential did not differ between treatments (p > .05). It was concluded that ovine serum enriched with vitamin E and vitamin E + FO improved the quality of human spermatozoa but enriched serum containing FO could not improve the sperm cryo-injuries.

Amelioration effects of n-3, n-6 sources of fatty acids and rosemary leaves powder on the semen parameters, reproductive hormones, and fatty acid analysis of sperm in aged Ross broiler breeder roosters

This study was conducted to evaluate the effects of dietary polyunsaturated fatty acids (PUFA) sources and rosemary leaves powder (RLP) on the semen quality, fatty acid analysis, and some reproductive hormones of senescent broiler breeder roosters. Thirty-five 45-wk-old Ross breeder roosters were randomly divided into 7 groups (5 birds/group), and received following treatments including control group (basal diet), fish oil (2%), corn oil (2%), an equal (50:50%) proportion of fish oil and corn oil (50:50%), fish oil (2%) with 5 g/kg capsulated RLP, corn oil (2%) with 5 g/kg capsulated RLP, and an equal (50:50) proportion of fish oil and corn oil (50:50%) with 5 g/kg capsulated RLP of diet for 60 D, during which time their seminal characteristics were evaluated every 20 D. At the end of the trial (on day 60), semen samples were tested for determination of sperm fatty acid analysis, lipid peroxidation, and some reproductive hormones. Results showed that feeding fish oil and fish/corn oil with RLP was associated with an increase in docosahexaenoic acid (C22:6n-3) and docosatetraenoic acid (C22:4n-6) in sperm. The fish oil diet increased the proportion of n-3 fatty acids in sperm, and as a consequence, the (n-6)/(n-3) ratio also decreased (P < 0.05). RLP (5 g/kg) to the fish and fish/corn-oil (50:50%)-based diet resulted in improvement in sperm concentration, total motility (%), sperm progressive motility (%), membrane integrity, and viability in terms 0 to 60 day trial (P < 0.05). Diets and age interacted to positively affect sperm concentration and sperm membrane integrity. Also this herbal antioxidant decreased the seminal content of malondialdehyde (MDA) significantly (P < 0.05). Testosterone and LH serum levels of reproductive hormones were significantly higher in fish and fish/corn-oil with RPL (50:50%)-based diet than other groups (P < 0.05). It can be concluded that RLP as an antioxidant could remarkably improve the effects of n-3 and n-3/n-6 PUFA on sperm characteristics, seminal MDA, and hormones levels in aged breeder roosters. The susceptibility of semen to lipid peroxidation was increased in chickens fed without RLP. Future studies are needed to disclose the causal mechanisms involved.

Changes in seminal parameters and hormonal profile with use of aromatase inhibitor in management of aging broiler breeder roosters

An excessive amount of aromatase enzyme reduces reproductive performance in aging roosters. Testosterone metabolism by aromatase enzyme is one of the reasons for reduced testosterone and lower fertility of aging roosters. The purpose of this study was to determine the effects of Exemestane (EX), as a steroidal aromatase inhibitor, on the seminal parameters and reproductive hormones of aging roosters. A total of 20 roosters (45 wk of age) were housed in individual cages and received a standard basal diet and oral EX capsules for 60 D at the daily doses per rooster (mg/rooster) in the following experimental groups: 0 mg (CTRL), 0.25 mg (Ex-0.25), 0.5 mg (Ex-0.5), and 1.5 mg (Ex-1.5). Sperm samples were obtained on days 1, 20, 40, and 60 of experiment. Blood samples were taken on days 1 and 60. The results indicated that different EX dosages affected semen parameters (P < 0.05) other than semen volume, morphology, apoptosis, and acrosome integrity. Various semen characteristics were significant (P < 0.05) during different times of the experiment, with the exception of semen volume, total motility, membrane integrity, morphology, apoptosis, and acrosome integrity. Roosters that received 0.5 mg of EX had higher percentages of sperm concentration, total motility, progressive motility, membrane integrity, viability, and mitochondrial activity (P < 0.05). There were lower concentrations of malondialdehyde in the CTRL (0 mg) and Ex-0.25 groups (P < 0.05). Although there was no significant difference in hormones at day 0 of the experiment (P > 0.05), roosters in the Ex-0.5 had higher concentration of testosterone as well as lower of aromatase activity at day 60 (P < 0.05). It can be concluded that EX improved semen parameters and testosterone, which ultimately can increase fertility in the aging broiler breeder roosters.

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.