Impact of cryopreservation protocols (one- and two-step) on boar semen quality at 5 °C and post-thawing.

The two-step protocol (2 S) is currently used for boar semen cryopreservation. In this method, the cryoprotectant penetrant agents (CPAs) are added at 5 °C to reduce the toxicity of CPAs. An alternative is the one-step protocol (1 S), which is easier, cheaper, and reduces the necessity of equipment, but could increase the toxicity of CPAs.

Metabolomic signature of spermatozoa established during holding time is responsible for differences in boar sperm freezability†.

Holding at room temperature is the first step in most boar semen cryopreservation protocols. It is well accepted that a holding time (HT) of 24 h increases sperm cryotolerance. However, the effect of HT on ejaculates with different freezability is not entirely clear.

Altrenogest during early pregnancy modulates uterine glandular epithelium and endometrial growth factor expression at the time implantation in pigs.

This study evaluated the effects of supplying altrenogest from day 6-12 of pregnancy on the endometrial glandular epithelium, corpora lutea (CL) morphology, and endometrial and CL gene expression. A total of 12 crossbred females (Landrace × Large White) were used. The females were assigned to 4 treatments according to a random design with a 2 × 2 factorial arrangement, with two categories (sow or gilt) and two treatments (non-treated and treated with altrenogest).

The use of resveratrol decreases liquid-extend boar semen fertility, even in concentrations that do not alter semen quality.

In vitro and in vivo assays were conducted to investigate the effects of trans-resveratrol (RVT) on liquid-extended boar semen during 72 h of storage at 17 °C. Thirty-six ejaculates were collected from six boars, evaluated, and extended. RVT was then added at the indicated treatment concentration (0, 0.

CyanoMetDB, a comprehensive public database of secondary metabolites from cyanobacteria.

Harmful cyanobacterial blooms, which frequently contain toxic secondary metabolites, are reported in aquatic environments around the world. More than two thousand cyanobacterial secondary metabolites have been reported from diverse sources over the past fifty years. A comprehensive, publically-accessible database detailing these secondary metabolites would facilitate research into their occurrence, functions and toxicological risks.

Cholesterol-loaded cyclodextrin is efficient in preserving sperm quality of cryopreserved ram semen with low freezability.

Semen freezability is positive correlated with the cholesterol content in the sperm cell. Freeze-thawing mainly cause temperature chock and change on media osmolarity, which can modify plasma membrane lipids content and sperm conformation, resulting in decreased fertility. Therefore, the aim of this study is to investigate the effect of adding cholesterol-loaded cyclodextrin (CLC) to the cryopreservation process of ram semen with low freezability.

Antioxidant Effect of a Polyphenol-Rich Murtilla ( Turcz.) Extract and Its Effect on the Regulation of Metabolism in Refrigerated Boar Sperm.

The production of reactive oxygen species (ROS) in boar spermatozoa increases in refrigeration; this can have an impact on sperm quality and fertilization capacity. We evaluated the effect of polyphenol-rich aqueous extract of murtilla ( Turcz) on boar sperm stored at 17°C in order to reduce oxidative stress and improve sperm quality in the long term. Five experiments were performed: first, characterization of the polyphenol content from five genotypes of murtilla; second, determination of the genotype with the best antioxidant effect (MT-Ex); third, the antioxidant capacity on O and lipid peroxidation; fourth, the influence of MT-Ex on motility, calcium movement, cAMP, and metabolic parameters; and fifth, analysis of long-term refrigeration.

The ideal holding time for boar semen is 24 h at 17 °C prior to short-cryopreservation protocols.

Boar semen cannot be immediately cryopreserved, it need be hold at 17 °C prior to cryopreservation, holding time has been used to improve cryopreserved boar semen, since holding time allows a prolonged interaction between spermatozoa and seminal plasma components. However, until now only few periods of holding time have been studied, and boar semen had been held at 17 °C for 24 h to facilitate its manufacture. Thus, this experiment aims to study the effect several holding time (0, 4, 8, 12, 24, 28 and 32 h) on boar spermatozoa post-thawed (PT) characteristics.

Does low-level laser therapy on degenerated ovine testes improve post-thawed sperm characteristics?

Low-level laser therapy (LLLT) can modulate redox state of the cell which could be useful to treat testicular degeneration and also prevent injuries by sperm cryopreservation. The aim of this study was to evaluate the effects of LLLT treatment on semen cryopreservation from rams submitted or not to testicular degeneration by testicular insulation. Eleven White Dorper rams were divided into four groups: animals that were not insulated (Control) and not treated (No Laser) (n = 2); animals that were not insulated and treated with LLLT (n = 3); animals that were insulated and not treated with LLLT (n = 3), and animals that were insulated and treated with LLLT (n = 3).

Removal of seminal plasma prior to liquid storage of boar spermatozoa: A practice that can improve their fertilizing ability.

Seminal plasma (SP) plays a vital role in the maintenance of sperm function and integrity along with being involved in their communication with the female reproductive tract. Under in vitro conditions, although it is generally accepted that boar semen is better preserved when SP is diluted (extended) or removed (cryopreserved), its role during storage is not completely elucidated. In this context, the current study sought to determine the role of SP during storage of boar spermatozoa at 17 °C for 72 h.

Nitric oxide in frozen-thawed equine sperm: Effects on motility, membrane integrity and sperm capacitation.

Nitric oxide (NO) is a reactive nitrogen species (RSN) that, over the years, has been shown to be integrated with biological and physiological events, including reproductive processes. NO can affect the functionality of spermatozoa through free radical scavenging, deactivating and inhibiting the production of superoxide anions (O). However, the role of NO in mammalian spermatozoa physiology seems paradoxical.

Novel Flow Cytometry Analyses of Boar Sperm Viability: Can the Addition of Whole Sperm-Rich Fraction Seminal Plasma to Frozen-Thawed Boar Sperm Affect It?

Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques include a single or dual sperm parameter analysis, which overrates the real sperm viability.

Recovery of normal testicular temperature after scrotal heat stress in rams assessed by infrared thermography and its effects on seminal characteristics and testosterone blood serum concentration.

Reestablishment of testicular normal temperature after testicular heat stress is unknown and its effect varies widely. The aim of this study was to investigate the impact of scrotal insulation (IN) on testicular temperature and its relation to semen quality and testosterone blood serum concentration. For this, 33 rams were used; 17 submitted to IN for 72 hours (using bags involving the testes) and 16 not submitted to IN (control group).

Low-level laser therapy to recovery testicular degeneration in rams: effects on seminal characteristics, scrotal temperature, plasma testosterone concentration, and testes histopathology.

The aim of this study was to investigate the efficiency of low-level laser therapy (LLLT) to recovery testicular degeneration in rams. In the first study, rams were induced to testicular degeneration by scrotal insulation, and then, they were treated using LLLT at 28 J/cm(2) (INS28) or 56 J/cm(2) (INS56) energy densities. Sperm kinetics, morphology, and membranes integrity as well as proportion of lumen area in seminiferous tubule were assessed.