Effect of dietary grape marc on fresh and refrigerated boar semen

Wine Grape Pomace as a Dietary Supplement to Improve Semen Quality in Boars

Boar spermatozoa are highly susceptible to oxidative damage due to their high content of unsaturated fatty acids, which are prone to disruption by reactive oxygen species (ROS). Excessive ROS can induce lipid peroxidation, DNA fragmentation and impaired enzyme activity, ultimately reducing sperm quality and reproductive performance. Wine grape pomace (WGP), a by-product of the winemaking process, is rich in polyphenols, including flavonoids (anthocyanins and quercetin), stilbenes (resveratrol) and tannins, which possess strong antioxidant properties. This study aimed to evaluate the effects of dietary supplementation with 4% WGP on boar ejaculate output and sperm quality during storage. Twenty boars were divided into two groups: a control group fed a standard diet and a WGP group supplemented with 4% WGP for 4 months. Semen samples were collected and analysed for ejaculate number of sperm per ml, total antioxidant capacity (in seminal plasma) and quality parameters (motility, kinematic parameters, mitochondrial activity, acrosome integrity, viability) after 1, 3 and 5 days of refrigerated storage. Results showed that WGP supplementation increased the number of sperm per ml compared to the control group (p < 0.05), resulting in approximately two additional seminal doses per ejaculate, without negatively affecting other seminal parameters (p > 0.05) and refrigeration storage (p > 0.05). This improvement in sperm concentration could enhance the profitability of swine semen production by increasing the number of doses produced per boar annually. Given the low cost of WGP (10.03 €/boar/year), this strategy could offer a cost-effective approach to improving reproductive performance in boars. These findings support further research into optimising WGP inclusion levels and exploring its broader impacts on boar fertility and reproductive efficiency.

Polyphenols as a strategy for improving male reproductive system

Reproduction in males is one of the complicated processes that is mediated by many environmental factors, as well as by diet (e.g. supplements, nutritional value). The parameters of reproduction like sperm cells, hormones and testicular histology are highly prone to oxidative stress due to influence of factors on reproductive processes. Polyphenols are naturally present in feed of animals as shrubs, trees and agro-industrial by products. The exposures of these polyphenols through diet have strong antioxidants properties. However, the benefits of these substances on reproductive health are not always certain. The use of these polyphenols in the diet of animals and in the semen extender has been reported as remarkable benefits. These beneficial effects are manifested in the form of improvement of antioxidant potential via the reduction in the production of reactive oxygen species. Polyphenols are also used for cryopreservation of various species for the genetic improvement of various species. This review gathers all the findings related to dietary consumptions of polyphenols on reproductive performance of male of various species as well as use in semen extender in fresh and frozen semen.

Selenium Nanoparticles as Potential Antioxidants to Improve Semen Quality in Boars

Selenium is an essential compound which can influence the fertility of boars by a greater margin. In past decades, research was mainly focused on a bioavailability of various selenium forms and the effect on semen quality. Recently, nanotechnology has expanded the possibilities of selenium supplementation research. Twenty-one Duroc boars (three groups with seven boars each) were included in this experiment with the first group being a control group with no selenium supplementation, and the second group being supplemented with 0.3 mg Se/kg of selenium in inorganic form of Na2SeO3. The third group was supplemented with selenium nanoparticles (100 nm) at the same dose as that of the second group. The experiment lasted for 126 days (three spermatogenesis cycles of boars) and the antioxidant parameters of boar semen were analysed at 42, 84 and 126 days, respectively. The antioxidant parameters (DPPH, FRAP, DMPD, GSH, GSSG) were not influenced by both Se2NO3 and selenium nanoparticle supplementation during this experiment. At the end of the monitored period, significantly higher (p < 0.004) antioxidant readings were observed by using the ABTS method but not the DPPH, DMPD and FRAP methods on the supplemented groups compared to the control. Moreover, selenium-nanoparticle-supplemented groups showed elevated glutathione peroxidase activity in the seminal fluid (p < 0.008). However, the selenium nanoparticle supplementation has not shown an improving effect on sperm quality. This could be considered as a safe alternative to inorganic selenium as well as having a potential to enhance the antioxidant properties of the semen of boars.

Current Options in the Valorisation of Vine Pruning Residue for the Production of Biofuels, Biopolymers, Antioxidants, and Bio-Composites following the Concept of Biorefinery: A Review

Europe is considered the largest producer of wine worldwide, showing a high market potential. Several wastes are generated at the different stages of the wine production process, namely, vine pruning, stalks, and grape marc. Typically, these residues are not used and are commonly discarded. Portugal generates annually approximately 178 thousand metric tons of wine production waste. In this context, the interest in redirecting the use of these residues has increased due to overproduction, great availability, and low costs. The utilization of these lignocellulosic biomasses derived from the wine industry would economically benefit the producers, while mitigating impacts on the environment. These by-products can be submitted to pre-treatments (physical, chemical, and biological) for the separation of different compounds with high industrial interest, reducing the waste of agro-industrial activities and increasing industrial profitability. Particularly, vine-pruning residue, besides being a source of sugar, has high nutritional value and may serve as a source of phenolic compounds. These compounds can be obtained by bioconversion, following a concept of biorefinery. In this framework, the current routes of the valorisation of the pruning residues will be addressed and put into a circular economy context.

The Antibacterial and Antioxidant Roles of Buckwheat Honey (BH) in Liquid Preservation of Boar Semen

In the present study, we hypothesized that buckwheat honey (BH) should be regarded as a potential alternative to antibacterial and antioxidant agent in liquid storage of boar semen. To this end, boar semen was firstly studied for in vitro dose tolerability to BH by measuring sperm progressive motility. The optimum progressive motility of boar spermatozoa was observed in extender with 0.5% and 0.6% BH addition. Afterward, sperm quality parameters, bacterial profile and composition, total antioxidant (T-AOC), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels of control, BH supplementation, antibiotics supplementation, and incorporated supplementation were compared during liquid storage period, to further investigate antibacterial and antioxidant properties of BH. The results showed that BH supplementation significantly improved sperm motility, acrosome integrity, plasma membrane integrity, inhibited opportunistic bacterial growth, and altered microbial compositions at the end of preservation. Additionally, T-AOC, SOD, and CAT levels were significantly higher in the BH supplementation group than those in the control and antibiotic supplementation group, whereas MDA level exhibited opposite change pattern. Importantly, BH addition to the extender was able to exert a synergistic effect in combination of antibiotic use. Our findings suggested that the appropriate concentrations (0.5% and 0.6%) of BH were added to the extender could act antibacterial and antioxidant roles in liquid preservation of boar semen.

Herbal foodstuffs in Avicenna's recommended diet to improve sperm quality and increase male fertility; an evidence-based approach

Attention to diet was considered important issues in improvement of men infertility in Persian Medicine (PM). The purpose of this study was to extract herbal foodstuffs introduced by Avicenna, one of the greatest PM physicians to improve the semen production and to provide evidence of their impact on the basis of current studies."Canon of Medicine", the most important Avecinna's book, was searched with keywords equivalent to semen, fertility and infertility, main herbal foodstuffs were extracted and was searched with keywords sperm, semen, infertility, and fertility in Google scholar, PubMed and Scopus databases. Manuscripts from 1950 up to December 2019 were selected and reviewed. Almond, Onion, Chickpea, Garlic, Coconut, Palm date, Sesame, Fenugreek, Carrot, Fig, Grapes, Pistachio, Hazelnut and Walnut are among main foodstuffs which recommended by Avicenna and there is also evidence that they have positive effects on testosterone production and improvement of various sperm parameters, including count, motility and morphology. Containing large amount of different macro and micronutrients such as vitamins including vit B, C, A and E, minerals such as Mg, Se, Zn, Cu and Fe, important unsaturated fatty acids such as linoleic and oleic acids, amino acids such as lysine and arginine and phytochemicals such as polyphenols, flavonoids, triterpenes and steroids can be considered as a main factor in the effectiveness of these foodstuffs. Designing a diet based on the fruits, vegetables, nuts and seeds that Avicenna has recommended, may be effective in treating male infertility but further studies are needed to clarify this issue. Research on the effectiveness of his other recommended foodsuffs may also offer new treatments and supplements for this purpose.

Polyphenols in Farm Animals: Source of Reproductive Gain or Waste?

Reproduction is a complex process that is substantially affected by environmental cues, specifically feed/diet and its components. Farm animals as herbivorous animals are exposed to a large amount of polyphenols present in their natural feeding system, in alternative feed resources (shrubs, trees, and agro-industrial byproducts), and in polyphenol-enriched additives. Such exposure has increased because of the well-known antioxidant properties of polyphenols. However, to date, the argumentation around the impacts of polyphenols on reproductive events is debatable. Accordingly, the intensive inclusion of polyphenols in the diets of breeding animals and in media for assisted reproductive techniques needs further investigation, avoiding any source of reproductive waste and achieving maximum benefits. This review illustrates recent findings connecting dietary polyphenols consumption from different sources (conventional and unconventional feeds) with the reproductive performance of farm animals, underpinned by the findings of in vitro studies in this field. This update will help in formulating proper diets, optimizing the introduction of new plant species, and feed additives for improving reproductive function, avoiding possible reproductive wastes and maximizing possible benefits.

Dietary Grape Pomace Supplementation in Dairy Cows: Effect on Nutritional Quality of Milk and Its Derived Dairy Products

Grape pomace (GP) is the main solid by-product of winemaking and represents a rich source of potent bioactive compounds which could display a wide range of beneficial effects in human health for their association with reduced risk of several chronic diseases. Several studies have proposed the use of GP as a macro-ingredient to obtain economically worthwhile animal feedstuffs naturally enriched by polyphenols and dietary fibers. Moreover, the research carried out in this field in the last two decades evidences the ability of GP to induce beneficial effects in cow milk and its derived dairy products. First of all, a general increase in concentration of polyunsaturated fatty acids (PUFA) was observed, and this could be considered the reflection of the high content of these compounds in the by-product. Furthermore, an improvement in the oxidative stability of dairy products was observed, presumably as a direct consequence of the high content of bioactive compounds in GP that are credited with high and well-characterized antioxidant functions. Last but not least, particularly in ripened cheeses, volatile compounds (VOCs) were identified, arising both from lipolytic and proteolytic processes and commonly associated with pleasant aromatic notes. In conclusion, the GP introduction in the diet of lactating cows made it possible to obtain dairy products characterized by improved nutritional properties and high health functionality. Furthermore, the presumable improvement of organoleptic properties seems to be effective in contributing to an increase in the consumer acceptability of the novel products. This review aims to evaluate the effect of the dietary GP supplementation on the quality of milk and dairy products deriving from lactating dairy cows.