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

Evaluation of Dry Ice for Short-Term Storage and Transportation of Frozen Boar Semen

To address the safety problems posed by the transportation of boar semen using LN, this study was conducted on the short-term storage of frozen boar semen in dry ice (-79 °C). Boar semen frozen in LN was transferred to dry ice, kept for 1 day, 3 days, 5 days, 7 days, or 8 days, and then moved back to LN. The quality of frozen semen stored in LN or dry ice was determined to evaluate the feasibility of short-distance transportation with dry ice. The results showed that 60 °C for 8 s was the best condition for thawing frozen semen stored in dry ice. No significant differences in spermatozoa motility, plasma membrane integrity, or acrosome integrity were observed in semen after short-term storage in dry ice compared to LN (p > 0.05). There were no significant changes in antioxidant properties between storage groups either (p > 0.05). In conclusion, dry ice could be used as a cold source for the short-term transportation of frozen boar semen for at least 7 days, without affecting sperm motility, morphological integrity, or antioxidant indices.

Over 100 years of vitamin E: An overview from synthesis and formulation to application in animal nutrition

The groundbreaking discovery of vitamin E by Evans and Bishop in 1922 was an important milestone in vitamin research, inspiring further investigation into its crucial role in both human and animal nutrition. Supplementing vitamin E has been proved to enhance multiple key physiological systems such as the reproductive, circulatory, nervous and muscular systems. As the main antioxidant in the blood and on a cellular level, vitamin E maintains the integrity of both cellular and vascular membranes and thus modulates the immune system. This overview showcases important and innovative routes for synthesizing vitamin E on a commercial scale, provides cutting-edge insights into formulation concepts for successful product form development and emphasizes the importance and future of vitamin E in healthy and sustainable animal nutrition.

L-arginine supplementation minimizes aging-induced changes in the sperm chromatin of roosters

Arginine is the main amino acid that constitutes the sperm protamine of roosters, named galline, which complexes with sperm DNA, allowing high compaction of its chromatin. Arginine supplementation has positive effects on semen quality in aged roosters, but this supplementation is not known to limit the progressive worsening of sperm chromatin compaction. This work aimed to verify whether L-arginine supplementation in the feed improve or maintain sperm chromatin quality since aging in roosters is usually accompanied by worsening chromatin quality. Four groups of 52-wk-old Ross AP95 lineage roosters were used, of which 6 semen samples per group were evaluated, totaling 24 samples. Another 24 samples, 6 per group, were evaluated after 6 wk of supplementation when one group was not supplemented (control) and the other 3 were supplemented with 1.15 kg (treatment 1), 2.17 kg (treatment 2), and 3.18 kg (treatment 3) of L-arginine/ton of feed. Computer image analysis of semen smears stained with toluidine blue pH 4.0 was used for sperm chromatin evaluation. Sperm chromatin was evaluated for compaction heterogeneity and compaction intensity by percentage decompaction relative to standard heads and by integrated optical density (IOD), which was used for the first time to identify sperm chromatin changes. Sperm head morphology was also evaluated by means of area and length. The IOD proved to be more efficient in identifying changes in rooster sperm chromatin compaction than the percentual decompaction. In general, chromatin compaction was positively influenced by the supplementation with L-arginine, being better in the supplementation with the highest levels tested. This was corroborated by the smaller average of the variables referring to the size of the spermatozoa heads of the animals that received feed with a higher content of L-arginine, since better compacted heads naturally tend to be smaller. Finally, arginine supplementation was able to limit or even improve sperm chromatin decompaction during the experimental period.

Alpha-tocopherol enhances spermatogonial stem cell proliferation and restores mouse spermatogenesis by up-regulating BMI1

Purpose

Spermatogonial stem cells (SSCs) are essential for maintaining reproductive function in males. B-lymphoma Mo-MLV insertion region 1 (BMI1) is a vital transcription repressor that regulates cell proliferation and differentiation. However, little is known about the role of BMI1 in mediating the fate of mammalian SSCs and in male reproduction. This study investigated whether BMI1 is essential for male reproduction and the role of alpha-tocopherol (α-tocopherol), a protective agent for male fertility, as a modulator of BMI1 both in vitro and in vivo.

Methods

Methyl thiazolyl tetrazolium (MTT) and 5-ethynyl-2'-deoxyuridine (EDU) assays were used to assess the effect of BMI1 on the proliferative ability of the mouse SSC line C18-4. Real-time polymerase chain reaction (PCR), western blotting, and immunofluorescence were applied to investigate changes in the mRNA and protein expression levels of BMI1. Male mice were used to investigate the effect of α-tocopherol and a BMI1 inhibitor on reproduction-associated functionality in vivo.

Results

Analysis revealed that BMI1 was expressed at high levels in testicular tissues and spermatogonia in mice. The silencing of BMI1 inhibited the proliferation of SSCs and DNA synthesis and enhanced the levels of γ-H2AX. α-tocopherol enhanced the proliferation and DNA synthesis of C18-4 cells, and increased the levels of BMI1. Notably, α-tocopherol rescued the inhibition of cell proliferation and DNA damage in C18-4 cells caused by the silencing of BMI1. Furthermore, α-tocopherol restored sperm count (Ctrl vs. PTC-209, p = 0.0034; Ctrl vs. PTC-209 + α-tocopherol, p = 0.7293) and normalized sperm malformation such as broken heads, irregular heads, lost and curled tails in vivo, as demonstrated by its antagonism with the BMI1 inhibitor PTC-209.

Conclusion

Analysis demonstrated that α-tocopherol is a potent in vitro and in vivo modulator of BMI1, a transcription factor that plays an important role in in SSC proliferation and spermatogenesis. Our findings identify a new target and strategy for treating male infertility that deserves further pre-clinical investigation.

The Effect of Semen Cryopreservation Process on Metabolomic Profiles of Turkey Sperm as Assessed by NMR Analysis

Semen cryopreservation represents the main tool for preservation of biodiversity; however, in avian species, the freezing−thawing process results in a sharp reduction in sperm quality and consequently fertility. Thus, to gain a first insight into the molecular basis of the cryopreservation of turkey sperm, the NMR-assessed metabolite profiles of fresh and frozen−thawed samples were herein investigated and compared with sperm qualitative parameters. Cryopreservation decreased the sperm viability, mobility, and osmotic tolerance of frozen−thawed samples. This decrease in sperm quality was associated with the variation in the levels of some metabolites in both aqueous and lipid sperm extracts, as investigated by NMR analysis. Higher amounts of the amino acids Ala, Ile, Leu, Phe, Tyr, and Val were found in fresh than in frozen−thawed sperm; on the contrary, Gly content increased after cryopreservation. A positive correlation (p < 0.01) between the amino acid levels and all qualitative parameters was found, except in the case of Gly, the levels of which were negatively correlated (p < 0.01) with sperm quality. Other water-soluble compounds, namely formate, lactate, AMP, creatine, and carnitine, turned out to be present at higher concentrations in fresh sperm, whereas cryopreserved samples showed increased levels of citrate and acetyl-carnitine. Frozen−thawed sperm also showed decreases in cholesterol and polyunsaturated fatty acids, whereas saturated fatty acids were found to be higher in cryopreserved than in fresh sperm. Interestingly, lactate, carnitine (p < 0.01), AMP, creatine, cholesterol, and phosphatidylcholine (p < 0.05) levels were positively correlated with all sperm quality parameters, whereas citrate (p < 0.01), fumarate, acetyl-carnitine, and saturated fatty acids (p < 0.05) showed negative correlations. A detailed discussion aimed at explaining these correlations in the sperm cell context is provided, returning a clearer scenario of metabolic changes occurring in turkey sperm cryopreservation.