Wojciech Niżański

• Full Professor
• Head of Department at Wrocław University of Environmental and Life Sciences

This study elucidates the impact of aging on the cellular architecture of feline oocytes, with a particular emphasis on organelles essential for fertilization and embryo development. Using transmission electron microscopy (TEM), the research compares oocytes from prepubescent, cycling adult, and aged cats, revealing notable differences in the arran...

Tebuconazole (TEB), a fungicide that inhibits 14α-demethylase (CYP51) and disrupts ergosterol synthesis, poses environmental and health risks due to its persistence and low biodegradability. This study examined TEB in vitro effects on rooster spermatozoa. In Experiment 1, semen from 10 Green-legged Partridge roosters was incubated with TEB (0, 0.1,...

Background Accurately predicting male fertility is crucial for the animal breeding industry due to its significant economic implications. Existing literature suggests that mammalian fertility is partially dependent on sperm DNA integrity. However, routine semen analysis often fails to detect DNA damage and does not consistently correlate with field...

Our research focuses on semen collection from 42 African penguin males, grouped by age, habituation levels, and reproductive season timing. We assess behavioral and physiological responses to dorso-abdominal massage, evaluating species-specific seminal traits using conventional and advanced methods. Positive behavioral responses corresponded with s...

Imidacloprid (IMI), an insecticide from the neonicotinoid group widely used in agriculture, has drawn attention due to its potential harmful effects on non-target species, including bird populations. In the present work, we investigated the effect of IMI on avian semen by in vitro exposure of rooster spermatozoa to this pesticide. The semen was col...

Sperm membrane composition and biophysical characteristics play a pivotal role in many physiological processes (i.e. sperm motility, capacitation, acrosome reaction and fusion with the oocyte) as well as in semen processing (e.g. cryopreservation). The aim of this study was to characterize the fatty acid content and biophysical characteristics (ani...

Simple Summary Reliable assessment of ovarian tissue depends on the ability of the fixation protocol to preserve its near in vivo appearance and composition. The goal of this study was to find the most suitable fixation protocol for feline ovarian tissue. Equal ovarian tissue fragments were obtained and divided into three groups then fixed with thr...

ProAKAP4 is gaining increasing attention as a potential marker of semen quality in many species, but while there is a commercial kit for assessing proAKAP4 in the domestic cat, there are no publications about its use. The aim of this study was to evaluate the commercial proAKAP4 kit – Cat 4MID® Kit (SPQI – 4BioDx, Lille, France) for the assessment...

Background This study was conducted to find the best concentration of cholesterol-loaded cyclodextrin (CLC) which has a positive impact on canine post thaw semen quality. Three different concentrations of CLC (0.83 mg/ml; 1.66 mg/ml; 3.32 mg/ml) and 2-hydroxylpropyl-beta-cyclodextrin (HBCD) (1.66 mg/ml) were used in addition to cryopreservation ext...

Preface It is a privilege and a pleasure to introduce this scientific publication that compiles original and review manuscripts in Animal Perinatology. Veterinary medicine is advancing rapidly with the expansion of knowledge and emerging technologies. New medical specialization areas provide more precise understandings of numerous aspects of animal...

The evaluation of oocytes and zygotes, based on their size, shape and morphology, is a valuable tool for predicting subsequent embryo development. While this assessment is non-invasive and made possible with time-lapse monitoring systems, not all the assessment criteria used for zygotes with pale cytoplasm can be used for domestic cat zygotes, whic...

Introduction Due to their capacity to release growth factors and cytokines, co-culture using mesenchymal stem cells has been considered a good alternative to promoting the maturation of the oocytes and the embryo’s development quality in vitro in different mammalian species. In this regard, we investigated the effect of feline Wharton’s jelly MSCs...

The main cause of sperm chromatin damage is oxidative stress related to embryo development failure and adult infertility in mammals and also avian. Oxidative stress results in lipid peroxidation (LPO) causing cell damage. Lipid peroxidation is the oxidation of polyunsaturated fatty acids (PUFAs) in biological systems and causes changes in the physi...

The wisent (or European bison) Bison bonasus is a species that has gone through a bottleneck, resulting in a narrow gene pool of the current population. Presently, the protection program for this species, in addition to protecting the habitat, is aimed at preserving gene pool. One of its elements is creating a bank of gametes with the intention of...

Epididymal spermatozoa obtained post mortem are considered a valuable source of genetic material which is often irrevocably lost. This makes these gametes constitute a key element in protection and restitution programs. The wisent ( Bison bonasus , Linnaeus 1758) is a species that survived in zoos after extinction from its natural habitat. This res...

Introduction In tomcats, epididymal spermatozoa provide an additional source of male gametes available for cryopreservation. While this procedure is feasible, the survival rate and motility of epididymal cat spermatozoa are both low after thawing. Cryopreservation is known to induce oxidative stress in spermatozoa, with mitochondria and the plasma...

In brief Ovarian tissue cryopreservation and culture provide an option for fertility preservation without tissue grafting, but need optimization. This study reveals that vitrified bovine ovarian tissue can be cultured on agarose gel and maintain follicle morphology, low activation, and low apoptosis. Abstract Ovarian tissue preservation is hithert...

Feline herpesvirus type 1 (FHV-1) is an enveloped dsDNA virus belonging to the Herpesviridae family and is considered one of the two primary viral etiological factors of feline upper respiratory tract disease. In this study, we investigated the entry of FHV-1 into host cells using two models: the AK-D cell line and primary feline skin fibroblasts (...

Age and other factors like season and breed are often associated with sperm quality and fertility in domestic animals. Even though many studies assessed the relationship between the age of the male and sperm parameters, the effects have not been comprehensively evaluated. Changes in semen quality from pubertal (young) to adult and old age were iden...

Simple Summary Veterinary regenerative medicine is an area of active research in which mesenchymal stem cells are applied. Mesenchymal stem cells (MSCs)are cells that can be obtained from various adult tissues; these cells have an extraordinary quality of being able to self-renew and develop into other cells. MSCs can be used to treat orthopaedic c...

Computer-assisted sperm morphometry analysis is an advanced tool which allows to precise measure sperm head parameters like length, width, area, and perimeter. On the basis of these and calculated parameters, morphometric subpopulations of spermatozoa can be distinguished. In many species, the distribution of subpopulation within the ejaculate is r...

Simple Summary New cryopreservation methods for dog semen are constantly under investigation because the fertility results after insemination with frozen–thawed semen are still not satisfying. Most researchers do not investigate the fertilization ability of spermatozoa after the modification of cryopreservation protocols. In this study, we investig...

Simple Summary The work concerns upon the supplementation of linseed oil ethyl esters to boars in order to improve semen parameters. The study included two groups of animals each with n = 6 animals. The application of linseed oil ethyl esters at 3% to the complete feed mixture in the experimental group improved semen parameters. It significantly in...

Simple Summary Chemical signals are essential for communication between living organisms. Dogs possess two sensory organs enabling chemical communication: the main olfactory system and the vomeronasal organ (VNO). Additionally, contact chemoreception is also pertinent, by which non-volatile molecules, including but not limited to proteins, are reco...

Introduction This study aimed to investigate the effect of fluid bolus administration during epidural anesthesia (coload) in female dogs scheduled for elective cesarean section (CS). Hypotension is one of the most common complications of epidural (EA) and spinal (SA) analgesia, and in the case of cesarean section, it may pose a significant risk for...

Simple Summary Flow cytometry (FC) is the recommended technique for assessing sperm quality. In comparison with fluorescence microscopy (FM), FC supports analyses of much larger sperm populations and generates more reliable results. However, FC is not always accessible, and sperm populations are often evaluated with the use of FM. In the present st...

Background The objective of this study was to evaluate the relationship between the mode of anesthesia, the time form the induction to the extraction of a puppy and the immediate postnatal vitality and umbilical cord blood gases parameters in cesarean section derived-puppies. Two different anesthetic protocols were used: inhalation using isoflurane...

Sex pheromones are chemical substances secreted into the environment that affect the physiology and behavior of recipients. Females use these compounds during oestrus to attract males, which leads to attempts of mating. This study evaluates the influence of manual semen collection in male dogs, in the presence or absence of a female in estrus, on t...

Mesenchymal stromal/stem cells (MSCs) are a particular population of cells that play an essential role in the regeneration potential of the body. As a source of MSCs, the umbilical cord (UC) has significant advantages, such as a no-risk procedure of tissue retrieval after birth and the easiness of MSCs isolation. In the presented study, the cells d...

Despite established microscopic markers of feline oocyte quality, little is known about their ultrastructural traits. To the best of our knowledge, there is no published report analysing the effect of 24 and 48 h ovarian storage time on the domestic cat oocytes characteristics at the ultrastructural level. Oocytes (n = 30) were classified using the...

The genetic background of feline disorders of sex development (DSDs) is poorly understood. We performed comprehensive cytogenetic, molecular, and histological studies of 17 cats with abnormal external genitalia, unusual behavior, or tricolor coats (atypical in males). The DSD phenotype of three cats was associated with sex chromosome abnormalities:...

Practical relevance An infertile tom used to be a relatively rare presentation in feline practice. However, as a result of breeding strategies targeting specific morphological/behavioural traits, and the influence of inbreeding (especially practised in rare breeds), among other factors, feline infertility has become a genuine clinical problem. Furt...

Background The wisent ( Bison bonasus ) is a species that has undergone a population bottleneck. Homozygosity is prevalent within the population and may have a negative impact on semen quality in wisent bulls. Semen samples containing a large amount of functionally and morphologically impaired or dead spermatozoa have lower tolerance for cryopreser...

Simple Summary Benign prostatic hyperplasia affects over 80% of old, non-castrated male dogs. In many cases, the severity of the symptoms means that treatment is required. The treatment of choice is surgical castration, which is unacceptable for the owners of stud dogs who are interested in therapy that does not exclude their animals from breeding....

Cell cycle synchronization of donor cells is an important step in mammalian somatic cell nuclear transfer (SCNT). This study was designed to compare the efficiency of serum starvation (Ss) and contact inhibition (cI) on cell cycle synchronization of jaguarundi, manul, and domestic cat skin fibroblasts, in the production of G0/G1 cells suitable for...

Simple Summary The article summarizes the current knowledge on factors related to pregnancy, parturition, and newborns that affect the health status of a puppy and determine its chances for survival and development. The detailed information is provided in terms of breed predispositions, objectives of pregnancy monitoring, potential sources of compl...

Simple Summary The wisent (European bison) is a protected species. For this reason, we undertook the use of biotechnologies—such as in vitro maturation of oocytes, in vitro fertilization of matured oocytes, in vitro culture of embryos, and embryo vitrification—to establish a wisent embryo bank. The competencies of the vitrified embryos were tested...

Disorders of sex development (DSDs) are congenital malformations defined as discrepancies between sex chromosomes and phenotypical sex. Testicular or ovotesticular XX DSDs are frequently observed in female dogs, while monogenic XY DSDs are less frequent. Here, we applied whole genome sequencing (WGS) to search for causative mutations in XX DSD fema...

This study describes, for the first time, the relationship between morphology and ploidy in domestic cat embryos. Blastocyst morphology and quality were assessed using time-lapse recordings, while ploidy was analyzed using fluorescence in situ hybridization. Out of 54 blastocysts, clear fluorescence signals for all the molecular probes used were ob...

Simple Summary One of the methods used to assess semen quality is the hypo-osmotic swelling test (HOST). Different protocols for this test are available, including a very simple one: swelling of spermatozoa is induced by incubation in distilled water for 5 min. Such a protocol could have easily been introduced in clinical practice, but it has not y...

Simple Summary Artificial reproductive techniques (ART), such as cryopreservation of sperm cells and artificial insemination, are useful tools for species conservation. However, there is relatively little information published about their introduction into clinical practice for wild felids. The aim of this paper was to describe how those techniques...

This study evaluated how semen selection by single layer centrifugation (SLC) with Canicoll affects semen freezability in dogs. A total of eighteen ejaculates, collected from dogs with optimal and suboptimal semen quality (optimal: normal morphology (NM) ≥ 80%, n = 9; suboptimal: NM between 60 and 79%, n = 9), were divided into two aliquots and sub...

This case report presents an observation of the influence of meloxicam administration, during the periovulatory phase, on corpora lutea function in the domestic dog (Canis familiaris). A 2 year old female German Shepherd dog, with a level of progesterone suggestive of the periovulatory period (5.97 ng/mL), received a single subcutaneous injection o...

The iSperm® is a portable device for semen analysis. This study aimed to investigate its correlation with a conventional computer-assisted sperm analyzer (ISAS®v1) for the assessment of semen concentration and kinematic parameters in dogs (n = 224). The intra-assay variability of both devices and their ability to estimate semen concentration at a f...

Simple Summary Assessing semen quality in dogs requires experience and specialized equipment. Therefore, this study investigates the potential value of measuring the blood concentration of Anti-Müllerian hormone (AMH), a hormone produced by Sertoli cells, to predict semen quality in dogs. Forty-five healthy dogs were included in this study and thei...

Active link before February 24, 2022 https://authors.elsevier.com/a/1eMoW1M2wIBlXu Semen cryopreservation is a key biotechnological strategy used to preserve and protect genetic resources, which are subject to increasingly serious reductions in some species, and to protect animal biodiversity. Assisted reproductive techniques, however, are still n...

Oxidative stress in sperm is a phenomenon related to the increasing rate of oxidation of cellular components and the excessive production of reactive oxygen species (ROS). The high content of polyunsaturated fatty acids in bird sperm cell membranes renders these cells particularly susceptible to lipid peroxidation (LPO). Therefore, to ensure the pr...

During the ovarian cycle in domestic dogs, females do not accept males during the first days of estrus but become attractive to males from the beginning of proestrus, with this attractiveness persisting until the end of the estrus phase. It is believed that increased estradiol is responsible for the female attractiveness to the males. In this paper...

The aim of this study was to compare several culture systems for cat embryos. Domestic cat oocytes were matured in vitro (IVM), fertilized (IVF), and cultured individually or in groups in drops under oil (20 μL or 50 μL) and in 16 microwell dishes (Primo Vision®). Moreover, the effects of co-culture with a) uncleaved oocytes, b) homospecific and c)...

In cattle there are two types of the corpus luteum (CL): homogeneous (CLhom) and cavitary (CLcav). Although they are considered equal in their hormonal activity, the function of the CLcav is questioned by many veterinarians. In consequence, females with the CLcav are considered less valuable for assisted reproductive techniques such as embryo trans...

Most reports on the effect of freezing-thawing procedure on the sperm of red deer concern the Iberian deer. This study investigated the effect of cryopreservation on motility, membrane and DNA in- tegrity of epididymal sperm of European red deer. Samples of sperm were obtained post mortem from cauda epididymis (from 10 bucks). Samples were froz...

Highly active antiretroviral therapy (HAART) is used in HIV-infected patients. Alongside the prolongation of patients’ life, adverse side effects associated with long-term therapy are becoming an increasing problem. Therefore, optimizing of HAART is extremely important. The study is aimed at evaluating the toxicity of abacavir and etravirine in mon...

Simple Summary The study was conducted with the aim of visualizing sex chromosomes in domestic cat sperm. Our research was carried out using fluorescence in situ hybridization (FISH) technique and the microscopic analysis showed the presence of X and Y chromosomes in domestic cat spermatozoa. The procedure used for sperm decondensation and FISH is...

Disorders of sex development (DSD) caused by chromosome abnormalities are rarely diagnosed in dogs. In this report, there is a focus on five DSD cases in which the dogs had abnormal karyotypes. All animals were recognized by owners as females, however, these dogs had a large number of reproductive defects. Among these were abnormal external genital...

Simple Summary In cats, semen is collected by pharmacological stimulation. The administration of a drug that stimulates α2-adrenoceptors causes the expulsion of spermatozoa into the urethra. However, as the results are not always satisfactory, this method needs to be improved. There are nine subtypes of adrenoceptors that are involved in the contra...

In this study, we investigated the influence of long‐term administration of stiripentol on sex hormones and semen quality in young Wistar rats. Investigated animals received for 6 months either stiripentol or saline solution. After one month, stiripentol increased temporarily serum level of testosterone (p < 0.05) and FSH (p < 0.01). However, after...

Simple Summary This study was conducted with the aim of analyzing the morphokinetic parameters that determine the proper development of feline embryos in vitro. Our research was carried out using a time-lapse monitoring system shows that the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphologic...

Urethral catheterisation after medetomidine administration is the method of choice for semen collection in cats, but it yields variable results. This study tested whether scrotal manual stimulation can improve urethral sperm collection in domestic cats. The study was performed on 20 male cats, from which two urethral semen samples were collected, o...

Simple Summary The article presents the results of the clinical evaluation and umbilical cord blood analysis obtained from newborn pups delivered by the elective Caesarean section. In human medicine both the umbilical cord blood and Apgar score were proved to provide valuable information on neonatal status. In veterinary medicine very few reports c...

Simple Summary Shear wave elastography (SWE) is a new diagnostic method allowing for a non-invasive differential diagnosis between benign and malignant mammary tumors. Mammary tumors in dogs are often hormone-dependent, and a surgical approach is currently the most recommended method for the treatment of mammary neoplasia. However, preoperative, ph...

Simple Summary Programmed cell death (apoptosis) is a crucial process in spermatogenesis, responsible for the elimination of abnormal sperm cells and for the reduction of testicular volume outside the breeding season. Poor sperm morphology (teratozoospermia) and lower semen quality out of season are commonly observed in domestic cats, but the exact...

Ultrasonographic fetal biometry is a technique used in both human and veterinary medicine to predict parturition time and evaluate fetal development. In domestic cats, the parameters that have been examined so far are the inner chorionic cavity diameter (ICC), biparietal diameter (BPD), deep portion of diencephalotelencephalic vesicle (DPTV), femur...

The current population of wisents (Bison bonasus, Linnaeus 1758) originates from only 12 individuals that survived World War II in zoos and private enclosures. For better preservation of genetic variability, research is being conducted to introduce assisted reproductive techniques in this species. In this article, we describe the current state of k...

Simple Summary This study was conducted with the aim of determining the morphological similarities and developmental potential of oocytes obtained from adult and prepubertal domestic cats (Felis catus) and wild cats. The results of our research showed that ovaries obtained from prepubertal felids may be a rich source of good quality oocytes that ar...

Simple Summary This article presents the use of ultrasonography (basic and advanced techniques) in dogs suffering from benign prostate hyperplasia (BPH) for the assessment of the effects of two different medications: osaterone acetate (YpozaneTM), a registered drug for BPH in dogs, and deslorelin acetate (SuprelorinTM), registered for pharmacologic...

Disorders of sex development (DSD) are important causes of infertility and sterility, and are risk factors for gonadal carcinogenesis. Many DSDs are caused by genetic factors, mainly sex chromosome abnormalities or mutations of genes involved in sexual development, as well as structural variants (SVs) - large deletions, duplications, and insertions...

Acute phase proteins are blood components synthesized by hepatocytes, basic function of which is to defend the organism as part of the immune response to infl ammation, trauma, infection, stress, neoplasia. They trigger a complex systemic reaction in order to restore homeostasis recovery of the organism. Proinfl ammatory cytokines increase their ac...

Simple Summary Canine reproductive behavior can be easily observed; however, the mechanism of semiochemical signaling in this species is still not well understood. Despite numerous studies, no efficient, artificial canine sex pheromones are available. In most studies of canine semiochemical communication, female urine was believed to be a source of...

Simple Summary The article compares the treatment efficacy and adverse effects of two drugs used for benign prostate hyperplasia (BPH) therapy in dogs: YpozaneTM (osaterone acetate) and SuprelorinTM (deslorelin acetate). YpozaneTM is a registered medication for this condition in dogs, whereas SuprelorinTM is registered for pharmacological castratio...

Simple Summary This is an article presenting the clinical data on the incidence of difficult labour in dogs being mated without owners’ intentions (accidental mating, unplanned breeding). Despite the widespread availability of spaying and its safety, unplanned and unwanted pregnancies in dogs are still a frequent concern. Unfortunately, in 8.3% (76...

Simple Summary Assisted reproduction techniques (ART) are crucial for preserving endangered animal species. Cryopreservation by vitrification can maintain gamete viability for a long time. Efforts to preserve endangered species within the Felidae family are focused on developing appropriate ART procedures. The domestic cat is a good biomedical mode...

Domestic cats are frequently used as a research model for felid species that are threatened with extinction. Until now, the development of feline embryos has been evaluated using both classical observation methods and time-lapse monitoring (TLM). Blastocyst collapse observed using time-lapse cinematography is used as a predictor of blastocyst quali...

The chemokine chemerin is a novel adipokine involved in the regulation of energy metabolism but also female reproductive functions in mammals. Its effects on male fertility are less studied. Here, we investigated the involvement of chemerin in chicken male reproduction. Indeed, the improvement of the sperm of roosters is a challenge for the breeder...

The aim of this study was to evaluate the applicability of the Cryotech technique for the vitrification of domestic cat (Felis catus) oocytes, as a model for other feline species threatened with extinction. This technique, in which oocytes are stored in a minimal volume of medium, is already widely used in human assisted reproductive technology. In...