Reprodução equina: um modelo de ensino / Equine reproduction: a teaching model

Vivemos nos últimos anos um momento difícil em relação ao ensino de qualidade na medicina veterinária brasileira. Por sua vez, a equideocultura brasileira possui destaque internacional pela alta demanda de empregabilidade e pela excelência de seu plantel. Sempre a frente do seu tempo, a Pontifícia Universidade Católica do Paraná, a PUCPR, possui um curso de 28 anos de história, onde a excelência no ensino é reconhecida de norte a sul do país. Ao longo dessa história, um dos grandes diferenciais da universidade são os grupos de estudos, que são realizados por áreas específicas no curso e que acontecem no contraturno do estudante. Um dos primeiros grupos de estudos formados na PUCPR, foi em 2003: o Grupo de Estudos em Reprodução Animal. E com um grande interesse dos estudantes pela área de equinos, em 2008 nasce o Grupo de Estudos em Reprodução de Equídeos que perdura até os dias de hoje com o nome de Liga Acadêmica em Reprodução de Equídeos lado a lado da Liga Acadêmica de Reprodução de Bovinos. Desde então, na área da reprodução equina, um trabalho realizado com os estudantes que simula a vida real de um haras de criação e um centro de reprodução equina junto ao rebanho didático da instituição. O que torna esse modelo de ensino da PUCPR especial é como ele é conduzido, levando o estudante através de trilhas ao longo da graduação que permite que ele realmente se forme podendo trabalhar e exercer na plenitude a reprodução equina. Ao longo de 23 anos, se observa que os profissionais ligados a reprodução equina e bovina, egressos do curso de medicina veterinária da PUCPR são referências em renomados criatórios de equinos no Brasil. Com todo esse trabalho desenvolvido ao longo dos 5 anos com esses estudantes temos a tranquilidade e a satisfação de entregar a sociedade profissionais extremamente capacitados, e prontos para o mercado do cavalo, de forma ética e respeitando os cavalos e todas as formas de bem-estar animal.(AU)

In recent years, we have experienced a difficult time in relation to quality teaching in Brazilian veterinary medicine. On the other hand, the Brazilian equideoculture has international prominence due to the high demand for employability and the excellence of its herd. Always ahead of its time, the Pontifical Catholic University of Paraná, PUCPR, has a course of 28 years of history, where excellence in teaching is recognized from north to south of the country. Throughout this history, one of the great differentials of the university are the study groups, which are carried out by specific areas in the course, and which take place in the student's after-school period. One of the first study groups formed at PUCPR was in 2003: the Animal Reproduction Study Group. And with a great interest of students in the equine area, in 2008 the Equine Reproduction Study Group was born, which lasts until today under the name of Academic League in Equine Reproduction side by side with the Academic League of Bovine Reproduction. Since then, around equine reproduction, work has been carried out with students that simulates the real life of a stud farm and an equine reproduction center with the institution's didactic herd. What makes this PUCPR teaching model special is how it is conducted, taking the student through paths throughout graduation that allow him to really graduate, being able to work and fully exercise equine reproduction. Over 23 years, it has been observed that professionals linked to equine and bovine reproduction, graduates of the PUCPR Veterinary Medicine course, are references in renowned equine breeding centers in Brazil. With all this work developed over the 5 years with these students, we have the tranquility and satisfaction of delivering extremely qualified professionals to society, ready for the horse market, ethically and respecting horses and all forms of welfare animal.(AU)

The interaction between the environment and embryo development in assisted reproduction

It can be assumed that the natural processes of selection and developmental condition in the animal provide the best prerequisites for embryogenesis resulting in pregnancy and subsequent birth of a healthy neonate. In contrast, circumventing the natural selection mechanisms and all developmental conditions in a healthy animal harbors the risk of counteracting, preventing or reducing the formation of embryos or substantially restricting their genesis. Considering these facts, it seems to be obvious that assisted reproductive techniques focusing on early embryonic stages serve an expanded and unselected germ cell pool of oocytes and sperm cells, and include the culture of embryos outside their natural habitat during and after fertilization for manipulation and diagnostic purposes, and for storage. A significant influence on the early embryonic development is seen in the extracorporeal culture of bovine embryos (in vitro) or stress on the animal organism (in vivo). The in vitro production per se and metabolic as well as endocrine changes in the natural environment of embryos represent adequate models and serve for a better understanding. The purpose of this review is to give a brief presentation of recent techniques aimed at focusing more on the complex processes in the Fallopian tube to contrast in vivo and in vitro prerequisites and abnormalities in early embryonic development and serve to identify potential new ways to make the use of ARTs more feasible.(AU)

Ética e condicionamento de animais selvagens para a aplicação de técnicas de reprodução assistida / Ethics and conditioning of wild animals for the application of assisted reproduction techniques

A relação humano-animal é conhecida desde o período Mesolítico e vem evoluindo ao longo dos anos pela busca de interações cada vez mais positivas. A forma como os animais e os ambientes são tratados abre muitas discussões éticas e morais em várias correntes filosóficas. O fato é que a biodiversidade vem apresentando uma redução expressiva dentro de um contexto de sexta extinção em massa do planeta e, para muitas espécies, trabalhar manejo populacional envolvendo coleções ex situ, seria a única alternativa de sobrevivência. As informações sobre a biologia das espécies selvagens ainda são muito insipientes e, portanto, faz-se necessário desenvolver pesquisas básicas que colaborem com as Técnicas de Reprodução Assistida (ARTs). A possibilidade de se trabalhar dentro do conceito de Conservação Única possibilita uma interconexão entre os planos de ação in situ e ex situ, as ações antrópicas no meio ambiente (sustentabilidade) e as pesquisas que englobam a conservação. Para tanto, utilizar as técnicas de condicionamento, que são prática voltada ao manejo de bem-estar, associadas às biotecnologias reprodutivas tem sido um manejo cada vez mais utilizado, com sucesso para muitas espécies ameaçadas. Animais manejados dentro dos protocolos de boas práticas são grandes candidatos a fazer parte dos programas de conservação integrada.(AU)

The human-animal relationship has been known since the Mesolithic period and has evolved over the years in search of increasingly positive interactions. How animals and environments are treated opens up many ethical and moral discussions in various philosophical currents. The fact is that biodiversity has been showing a significant reduction within the context of the sixth mass extinction on the planet, and, for many species, working on population management involving ex situ collections would be the only alternative for survival. Information on the biology of wild species is still very incipient; therefore, it is necessary to develop basic research that collaborates with Assisted Reproduction Techniques (ARTs). Working within the One Conservation concept enables an interconnection between in situ and ex situ action plans, anthropic environmental actions (sustainability), and research that encompasses conservation. Therefore, using conditioning techniques­a practice aimed at welfare management­associated with reproductive biotechnologies has been increasingly used, with success for many endangered species. Animals handled within suitable practice protocols are great candidates to be part of integrated conservation programs.(AU)

Assisted Reproductive Technologies (ART) and genome editing to support a sustainable livestock

This article provides an overview of assisted reproductive technologies (ART) and genome engineering to improve livestock production systems for the contribution of global sustainability. Most ruminant production systems are conducted on grassland conditions, as is the case of South American countries that are leaders in meat and milk production worldwide with a well-established grass-feed livestock. These systems have many strengths from an environmental perspective and consumer preferences but requires certain improvements to enhance resource efficiency. Reproductive performance is one of the main challenges particularly in cow-calf operations that usually are conducted under adverse conditions and thus ART can make a great contribution. Fixed-time artificial insemination is applied in South America in large scale programs as 20 to 30% of cows receive this technology every year in each country, with greater calving rate and significant herd genetic gain occurred in this region. Sexed semen has also been increasingly implemented, enhancing resource efficiency by a) obtaining desired female replacement and improving animal welfare by avoiding newborn male sacrifice in dairy industry, or b) alternatively producing male calves for beef industry. In vitro embryo production has been massively applied, with this region showing the greatest number of embryos produced worldwide leading to significant improvement in herd genetics and productivity. Although the contribution of these technologies is considerable, further improvements will be required for a significant livestock transformation and novel biotechnologies such as genome editing are already available. Through the CRISPR/Cas-based system it is possible to enhance food yield and quality, avoid animal welfare concerns, overcome animal health threats, and control pests and invasive species harming food production. In summary, a significant enhancement in livestock productivity and resource efficiency can be made through reproductive technologies and genome editing, improving at the same time profitability for farmers, and global food security and sustainability.(AU)

Reprodução ex situ de felinos silvestres e seus desafios / Challenges of ex situ reproduction in wild cats

A reprodução ex situ de felinos silvestres assegura a sobrevivência das espécies ameaçadas por meio do estabelecimento e manutenção de populações viáveis em cativeiro. O conhecimento da biologia reprodutiva básica é essencial para o desenvolvimento de planos de manejo reprodutivo (PMRs) eficientes, seja pela reprodução natural ou pela aplicação de técnicas de reprodução assistida (TRAs). Os PMRs visam garantir a representatividade das espécies quanto à variabilidade genética e demográfica baseada nos studbooks. Entretanto, o pareamento de animais selecionados pelos PMRs deve levar em conta, além de fatores genéticos e demográficos, fatores comportamentais e o fenótipo dos animais, uma vez que pode haver consequências negativas caso descendentes de gerações futuras sejam reintroduzidos na natureza. As TRAs estão cada vez mais sendo desenvolvidas para auxiliar na manutenção de populações geneticamente viáveis ex situ que possam contribuir geneticamente com populações in situ. A criopreservação de sêmen e a inseminação artificial (IA) são as TRAs utilizadas atualmente pelos PMR nacionais e internacionais, no entanto, são muitos os desafios para que as populações cativas se reproduzam de maneira adequada visando a manutenção de uma população viável que possa contribuir com populações de vida livre no futuro.(AU)

Reproductive management plans are essential to ensure that imperiled populations maintain adequate genetic and demographic variability and remain representative of the species as a whole. Basic reproductive biology knowledge is essential for the development of efficient reproductive management plans (PMPs), either through natural breeding or through assisted reproductive techniques (ARTs). The PMPs aim to ensure the representativeness of the species in terms of genetic and demographic variability based on studbooks. However, the specific animal pairings should be maintaining adequate genetic, behavioral and the phenotype of the animals, ensuring proper reintroduction of animals into the wild. ARTs have been explored as a means to enhance the conservation of endangered species, focused on maintaining genetic diversity through enhanced animal propagation. Semen cryopreservation and artificial insemination (AI) are used by national and international PMRs, however, there are many challenges for captive populations reproduction in order to maintain a viable population that can contribute for freeliving populations in the future.(AU)

Applications of livestock monitoring devices and machine learning algorithms in animal production and reproduction: an overview

Some sectors of animal production and reproduction have shown great technological advances due to the development of research areas such as Precision Livestock Farming (PLF). PLF is an innovative approach that allows animals to be monitored, through the adoption of cutting-edge technologies that continuously collect real-time data by combining the use of sensors with advanced algorithms to provide decision tools for farmers. Artificial Intelligence (AI) is a field that merges computer science and large datasets to create expert systems that are able to generate predictions and classifications similarly to human intelligence. In a simplified manner, Machine Learning (ML) is a branch of AI, and can be considered as a broader field that encompasses Deep Learning (DL, a Neural Network formed by at least three layers), generating a hierarchy of subsets formed by AI, ML and DL, respectively. Both ML and DL provide innovative methods for analyzing data, especially beneficial for large datasets commonly found in livestock-related activities. These approaches enable the extraction of valuable insights to address issues related to behavior, health, reproduction, production, and the environment, facilitating informed decision-making. In order to create the referred technologies, studies generally go through five steps involving data processing: acquisition, transferring, storage, analysis and delivery of results. Although the data collection and analysis steps are usually thoroughly reported by the scientific community, a good execution of each step is essential to achieve good and credible results, which impacts the degree of acceptance of the proposed technologies in real life practical circumstances. In this context, the present work aims to describe an overview of the current implementations of ML/DL in livestock reproduction and production, as well to identify potential challenges and critical points in each of the five steps mentioned, which can affect results and application of AI techniques by farmers in practical situations.(AU)

Comparison of efficiency between two artificial insemination methods using fresh semen in domestic cat (Felis Catus) / Comparação da eficiência entre dois métodos de inseminação artificial utilizando sêmen fresco em gata doméstica (Felis Catus)

This study aimed to compare domestic cats' pregnancy rates using fresh semen for the bilateral intrauterine insemination (BIUI) method and the novel uterine body insemination (UBI) method. Queens received a single injection of equine chorionic gonadotropin (eCG) (200 IU; IM) to induce ovarian follicular development and, after 83 h, an injection of human chorionic gonadotropin (hCG) (100 IU; IM) for final oocyte maturation and ovulation induction. Thirty-four hours after hCG administration, 3 × 106fresh spermatozoa were used for insemination by the BIUI (n = 8 queens) or by the UBI (n = 7 queens) techniques,respectively. Pregnancy rates were 75.00% (6/8) by BIUI and 42.85% (3/7) by the UBI method. Themean litter size was 3.0 ± 0.86 for the BIUI, and 2.0 ± 1.0 for the UBI method. Spontaneous abortion occurred on day 35 of pregnancy in one queen following the UBI method. Our findings showed that the BIUI of queens with fresh semen resulted in higher pregnancy rates than the novel UBI method; also, acceptable pregnancy rates were achieved following BIUI with fresh semen in the domestic cat.(AU)

O objetivo deste estudo foi comparar as taxas de prenhez em gatas domésticas usando sêmen fresco para o método de inseminação intrauterina bilateral (BIUI) e o novo método de inseminação do corpo uterino (UBI). As gatas receberam uma única injeção de gonadotrofina coriônica equina (eCG) (200 UI; IM) para induzir o desenvolvimento folicular ovariano e, após 83 h, uma injeção de gonadotrofina coriônica humana (hCG) (100 UI; IM) para maturação final do oócito e ovulação indução. Trinta e quatro horas após a administração de hCG, 3 × 106 espermatozoides frescos foram utilizados para inseminação pelas técnicas de BIUI (n = 8 gatas) ou UBI (n = 7 gatas), respectivamente. As taxas de gravidez foram de 75,00% (6/8) pela BIUI e 42,85% (3/7) pelo método UBI. O tamanho médio da ninhada foi de 3,0 ± 0,86 para o método BIUI e 2,0 ± 1,0 para o método UBI. Aborto espontâneo ocorreu no dia 35 de gestação em uma gata seguindo o método UBI. Nossos achados mostraram que a BIUI de gatas com sêmen fresco resultou em maiores taxas de prenhez do que o novo método UBI; também, taxas de prenhez aceitáveis foram alcançadas após BIUI com sêmen fresco no gato doméstico.(AU)

Maternal contributions to pregnancy success: from gamete quality to uterine environment

The establishment and maintenance of a pregnancy that goes to term is sine qua non for the long-term sustainability of dairy and beef cattle operations. The oocyte plays a critical role in providing the factors necessary for preimplantation embryonic development. Furthermore, the female, or maternal, environment where oocytes and embryos develop is crucial for the establishment and maintenance of a pregnancy to term. During folliculogenesis, the oocyte must sequentially acquire meiotic and developmental competence, which are the results of a series of molecular events preparing the highly specialized gamete to return to totipotency after fertilization. Given that folliculogenesis is a lengthy process in the cow, the occurrence of disease, metabolic imbalances, heat stress, or other adverse events can make it challenging to maintain oocyte quality. Following fertilization, the newly formed embryo must execute a tightly planned program that includes global DNA remodeling, activation of the embryonic genome, and cell fate decisions to form a blastocyst within a few days and cell divisions. The increasing use of assisted reproductive technologies creates an additional layer of complexity to ensure the highest oocyte and embryo quality given that in vitro systems do not faithfully recreate the physiological maternal environment. In this review, we discuss cellular and molecular factors and events known to be crucial for proper oocyte development and maturation, as well as adverse events that may negatively affect the oocyte; and the importance of the uterine environment, including signaling proteins in the maternal-embryonic interactions that ensure proper embryo development. We also discuss the impact of assisted reproductive technologies in oocyte and embryo quality and developmental potential, and considerations when looking into the prospects for developing systems that allow for in vitro gametogenesis as a tool for assisted reproduction in cattle.(AU)

Applying assisted reproductive technology and reproductive management to reduce CO2-equivalent emission in dairy and beef cattle: a review

Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane. In addition to enteric methane (CH4) produced by the rumen, cattle production also contributes carbon dioxide (CO2) (feed), nitrous oxide (N2O) (feed production, manure) and other CH4 (manure) to the total greenhouse gas (GHG) budget of beef and dairy production systems. The relative contribution in standard dairy systems is typically enteric CH4 58%, feed 29% and manure 10%. Herds with low production efficiency can have an enteric CH4 contribution up to 90%. Digestibility of feed can impact CH4 emission intensity. Low fertility herds also have a greater enteric CH4 contribution. Animals with good feed conversion efficiency have a lower emission intensity of CH4/kg of meat or milk. Feed efficient heifers tend to be lean and have delayed puberty. Fertility is a major driver of profit in both beef and dairy cattle, and it is highly important to apply multi-trait selection when shifting herds towards improved efficiency and reduced CH4. Single nucleotide polymorphisms (SNPs) have been identified for feed efficiency in cattle and are used in genomic selection. SNPs can be utilized in artificial insemination and embryo transfer to increase the proportion of cattle that have the attributes of efficiency, fertility and reduced enteric CH4. Prepubertal heifers genomically selected for favourable traits can have oocytes recovered to produce IVF embryos. Reproductive technology is predicted to be increasingly adopted to reduce generation interval and accelerate the rate of genetic gain for efficiency, fertility and low CH4 in cattle. The relatively high contribution of cattle to anthropogenic global methane has focussed attention on strategies to reduce enteric CH4 without compromising efficiency and fertility. Assisted reproductive technology has an important role in achieving the goal of multiplying and distributing cattle that have good efficiency, fertility and low CH4.(AU)

The embryo non-invasive pre-implantation diagnosis era: how far are we?

Advancements in assisted reproduction (AR) methodologies have allowed significant improvements in live birth rates of women who otherwise would not be able to conceive. One of the tools that allowed this improvement is the possibility of embryo selection based on genetic status, performed via preimplantation genetic testing (PGT). Even though the widespread use of PGT from TE biopsy helped to decrease the interval from the beginning of the AR intervention to pregnancy, especially in older patients, in AR, there are still many concerns about the application of this invasive methodology in all cycles. Therefore, recently, researchers started to study the use of cell free DNA (cfDNA) released by the blastocyst in its culture medium to perform PGT, in a method called non-invasive PGT (niPGT). The development of a niPGT would bring the diagnostics power of conventional PGT, but with the advantage of being potentially less harmful to the embryo. Its implementation in clinical practice, however, is under heavy discussion since there are many unknowns about the technique, such as the origin of the cfDNA or if this genetic material is a true representative of the actual ploidy status of the embryo. Available data indicates that there is high correspondence between results observed in TE biopsies and the ones observed from cfDNA, but these results are still contradictory and highly debatable. In the present review, the advantages and disadvantages of niPGT are presented and discussed in relation to tradition TE biopsy-based PGT. Furthermore, there are also presented some other possible non-invasive tools that could be applied in the selection of the best embryo, such as quantification of other molecules as quality biomarkers, or the use artificial intelligence (AI) to identify the best embryos based on morphological and/or morphokitetic parameters.(AU)

Colheita de sêmen e inseminação artificial em onças-pintadas (Panthera onca) / Semen collection and artificial insemination in jaguars (Panthera onca)

A onça-pintada encontra-se classificada como "quase ameaçada" na lista vermelha de animais ameaçados da União Internacional para Conservação da Natureza (IUCN), com tendência ao declínio na América Latina, o que pode afetar o fluxo gênico elevando o risco de endogamia. Técnicas de reprodução assistida (TRAs) como colheita de sêmen e inseminação artificial (IA), são ferramentas que podem se tornar essenciais a manutenção da diversidade genética desses animais. A colheita de sêmen pode ser realizada por eletroejaculação (EEJ) ou colheita farmacológica (CF), sendo que podem ser aplicadas individualmente ou associadas, embora EEJ tenha se mostrado mais eficiente em inseminação artificial (IA) com sêmen a fresco. Para realização de IA a utilização de progestina oral (altrenogest), seguida da aplicação de gonadotropinas exógenas (Gonadotropina Coriônica equina-eCG e Hormônio Luteinizante suíno-pLH), tem se mostrado eficiente, promovendo ovulações consistentes. IA intratubárica (IA-IT) mostrou-se eficiente, tendo a vantagem de utilizar sêmen com baixo número de espermatozoides. O sucesso alcançado com o nascimento do primeiro filhote de Panthera onca utilizando TRAs se deve a vários fatores, dentre eles, a utilização de um novo protocolo hormonal ajustado à espécie; e a utilização da IA-IT, que possibilitou a utilização de sêmen com reduzido número de espermatozoides viáveis por inseminação.(AU)

The jaguar is classified as "near threatened" according International Union for Conservation of Nature red list, with a decreasing trend in the population of Latin America, increasing the risk of inbreeding. Assisted reproduction techniques (ARTs), such as semen collection and artificial insemination (AI), are tools that can become essential to maintain the genetic diversity of jaguars. Semen collection can be performed by electroejaculation (EEJ) or pharmacological collection (PC); and can be applied individually or associated, however EEJ was more efficient for artificial insemination (AI) with fresh semen. To perform Artificial Insemination (AI), oral progestin (altrenogest) followed exogenous gonadotropins (Gonadotropin Chorionic equine-eCG e Hormone Luteinizing porcine-pLH) application was efficient, promoting consistent ovulations. Similarly, laparoscopic oviductal insemination (IA-IT) was efficient, with the advantage to use low viable spermatozoa number by insemination. The success of jaguar cub birth using ARTs is due to several factors, among than, a new hormonal protocol adjusted to the species; and the use of IA-IT, which allowed the reduction in the number of sperm by insemination.(AU)

Collecting information on estrus in cattle using the internet of things / Recolha de informações sobre o cio em bovinos utilizando a internet of things

Monitoring the movements of ruminant animals is one of the most challenging tasks. In animals that act according to their habits, it is difficult to label such movements and transfer them to farmers. Monitoring and recording the movement and behavior of animals on a farm is an adopted method for successfully determining the duration of the estrus cycle in ruminant animals. The Internet is a technology that offers remarkable solutions for such applications. The aim of this study is to determine the hourly step counts and to find the estrus period in the most accurate way with a circuit design applied to the ankles of animals using an IoT-supported microcontroller. The data is transferred to the web environment wirelessly and monitored via wi-fi communication signals. This wireless wearable and network equipment determines the step count and monitors the animal's abnormal body temperature. An IoT-supported microcontroller provides wireless communication, high-speed data transmission, and low power consumption. Insemination was ensured by testing different animals on the application farm. The data is monitored in real-time, and the system gives an alert. Low cost, high reliability, and being able to be watched over the internet are the advantages of the system. This study helped develop new techniques and provided a low-cost proposition for testing wearable technologies on animals.

A monitorização dos movimentos dos animais ruminantes é uma das tarefas mais difíceis. Em animais que agem de acordo com os seus hábitos, é difícil rotular esses movimentos e transferi-los para os agricultores. A monitorização e o registo dos movimentos e do comportamento dos animais numa exploração é um método adoptado para determinar com êxito a duração do ciclo de cio em animais ruminantes. A Internet é uma tecnologia que oferece soluções notáveis para tais aplicações. O objectivo deste estudo é determinar as contagens horárias de passos e encontrar o período de cio da forma mais precisa possível com um design de circuito aplicado aos tornozelos dos animais utilizando um microcontrolador suportado pela IoT. Os dados são transferidos para o ambiente Web sem fios e monitorizados através de sinais de comunicação wi-fi. Este equipamento vestível e de rede sem fios determina a contagem de passos e monitoriza a temperatura corporal anormal do animal. Um microcontrolador suportado pela IoT fornece comunicação sem fios, transmissão de dados a alta velocidade e baixo consumo de energia. A inseminação foi assegurada através de testes com diferentes animais na quinta de aplicação. Os dados são monitorizados em tempo real e o sistema emite um alerta. O baixo custo, a elevada fiabilidade e a possibilidade de ser observado através da Internet são as vantagens do sistema. Este estudo ajudou a desenvolver novas técnicas e forneceu uma proposta de baixo custo para testar tecnologias vestíveis em animais.

Use of new recombinant proteins for ovarian stimulation in ruminants

Currently, gonadotropin products (follicle stimulating hormone, FSH, and luteinizing hormone, LH) used in animal reproduction are produced by extraction and purification from abattoir-derived pituitary glands. This method, relying on animal-derived materials, carries the potential risk of hormone contamination and pathogen transmission. Additionally, chorionic gonadotropins are extracted from the blood of pregnant mares (equine chorionic gonadotropin; eCG) or the urine of pregnant women (human chorionic gonadotropin; hCG). However, recent advancements have introduced recombinant gonadotropins for assisted animal reproduction therapies. The traditional use of FSH for superovulation has limitations, including labor requirements and variability in superovulation response, affecting the success of in vivo (SOV) and in vitro (OPU/IVEP) embryo production. FSH treatment for superstimulation before OPU can promote the growth of a homogenous follicular population and the recovery of competent oocytes suitable for IVEP procedures. At present, a single injection of a preparation of long-acting bovine recombinant FSH (rFSH) produced similar superovulation responses resulting in the production of good-quality in vivo and in vitro embryos. Furthermore, the treatment with eCG at FTAI protocol has demonstrated its efficacy in promoting follicular growth, ovulation, and P/AI, mainly in heifers and anestrous cows. Currently, treatment with recombinant glycoproteins with eCG-like activity (r-eCG) have shown promising results in increasing follicular growth, ovulation, and P/AI in cows submitted to P4/E2 -based protocols. Bovine somatotropin (bST) is a naturally occurring hormone found in cows. Recombinant bovine somatotropin (rbST), produced through genetic engineering techniques, has shown potential in enhancing reproductive outcomes in ruminants. Treatment with rbST has been found to improve P/IA, increase donor embryo production, and enhance P/ET in recipients. The use of recombinant hormones allows to produce non-animal-derived products, offering several advantages in assisted reproductive technologies for ruminants. This advancement opens up new possibilities for improving reproductive efficiency and success rates in the field of animal reproduction.(AU)

Can we use reproductive biotechniques in cats like it is used in dogs?

In recent years, there has been a great interest of purebred cat breeders in the possibilities and benefits of implementing of consistent veterinary care on reproduction. This includes tools available in the field of Assisted Reproductive Technologies (ART). As in dogs before, there is a tendency to reduce the reproductive potential of purebred cats, which is partly due to the nature of the selection of animals for reproduction on the basis of phenotypic features, omitting the control of their fertility. It is worthy to note hazardous specificity of this selection where inbreeding is commonly used. If all this is imposed on the frequent occurrence of infectious diseases in a domestic cat, then the population of purebred cats appears as a group of animals, which is a kind of challenge for a specialist of reproduction. This is a paradoxical phenomenon, because regarding non-purebred cats, the main challenge for the veterinary community is to limit their population. Some of the most important barriers to the implementation of advanced control of reproduction of purebred cats over the years have been: 1) difficulties with sperm collection, 2) technically troublesome artificial insemination, 3) numerous and difficult to recognize and treat forms of fertility disorders. In recent years, progress has been observed within each of these areas. It is possible to implement into practice extremely valuable tools that are helpful in monitoring the reproductive status of these animals. The breakthrough was the development of effective methods of semen collection, its evaluation and preservation and the development of increasingly effective methods of artificial insemination. Therefore, there is a real prospect of organizing cat reproduction centers operating within veterinary facilities dealing with small animals. The time is coming to carry out veterinary care for cat reproduction at such an advanced level as it has been developed in recent decades for dogs. Development in this area is facilitated by progress in research on the field of the use of ART in programs of rescue of endangered feline species where domestic cat is treated as model animal.(AU)

Importance of the study of reproduction in small animals and preservation of species / Importancia del estudio de la reproducción en animales pequeños y la preservación de especies / Importância do estudo da reprodução em pequenos animais e preservação das espécies

Although reproduction in small animals is relatively current, its objectives are very varied. Initially they were used as a study model in physiology and various pathologies. In the same way, many small animals are produced as food and finally, in the last 20 years, the importance of pets and the intensification in the selection of canine and feline breeds, has caused an important impulse in the development of new scientific information. Although currently technical resources have advanced substantially, there are still many basic and important issues that have not yet been elucidated by formal science. Global threats facing wild species include the consequences of climate change, population growth, urbanization, air and water pollution, and the release of chemicals into the environment, causing, on average, 25% of animals are in danger of extinction. Wild animal populations are small and dispersed in their habitat with little or no opportunity for genetic exchange, which has generated in recent years many programs to preserve wild species and design appropriate strategies that lead to sustainable populations. Fortunately, recent and inspiring advances in the science of wildlife reproduction have been reported that will set directions for future research and will surely lead to further successes in conservation biology.(AU)

Assisted reproductive technologies used in small animal veterinary practice - possibilities, obstacles and future

Assisted Reproductive Technologies (ART) are currently used in animals usually in three main situations: 1. As a form of treatment of subfertility and infertility in females and/or males, 2. As a method to obtain genetically valuable progeny in relatively short time in healthy fertile animals, 3. As a modern smart tool to obtain progeny in endangered animal species in programs of rescue of wild animals threatened extinction. Generally the efficiency of reproductive biotechniques in dogs and cats is lower in comparison to obtained in farm animals and in human. Independently of the aim of their use, there are some techniques, which are better developed in dogs and some others seems to be better developed in cats. It may be assumed that simple, clinical techniques are well elaborated and more frequently used in dogs while more advanced techniques are better developed in cats. The level of effectiveness of ART is conditioned by anatomical and physiological factors specific for species, general demands for their use in veterinary practice and research, and general interest of breeders and scientific community in such activity.(AU)

Fertility disorders in male dogs

Male dog fertility disorders are usually troublesome and challenging for a practicing veterinarian. It may be generally assumed, that reproductive potential in this species is lower than in farm animals and it is still decreasing. This situation starts to be similar to human medicine, where we observe dramatic drop of reproductive capacity, which resulted in the need of implementation of Assisted Reproductive Technologies (ART). Situation in dogs is more complicated owing the fact, that the use of ART meets many obstacles. Low fertility potential in dogs appears to be the result of variable factors such as: specific criteria of selection for reproduction in which fertility performance in not a priority, lack of periodical obligatory fertility check, species specific predisposition for many reproductive diseases and no age limit for reproductive use of males. Dogs are kept in human environment and exposition for civilizational byproducts influences negatively not only on our health, but also on health our 'minor brothers'. It should be bear in mind, that reproductive organs are very sensitive for environmental factors disrupting homeostatic balance. The decline in male dog fertility over the past decades was proved, with potential link to environmental contaminants (4). They were found in pet foods and were also detected in the sperm and testes of adult dogs causing a detrimental effects on sperm function. Over the 26 years of the study of Lea et al. (4), authors found a decrease in the percentage of normal motile sperm. Between 1988 and 1998, sperm motility declined by 2.5 per cent per year. Then from 2002 to 2014 sperm motility continued to decline at a rate of 1.2% per year. In addition, the male pups had an increased incidence of cryptorchidism. Basics of physiology of reproduction of male dogs. Normally the puberty in males is associated with presence of normal sperm cells in genital organs. It is reached in male dogs at age around 5-6 months. Such a young dog obviously cannot be used for reproduction. Reproductive maturity is associated later, with development of normal sexual behavior and production of sufficient number of normal, fertilizing competent spermatozoa. It corresponds with 12-18 months of animal age. Testicular descent is completed usually before weaning period, but sometimes testicles may reach scrotum later, but never after the end of 6 month of age. That time inguinal canals start to be so narrow, that caudal passing of gonads is unlikely. Male dogs have only one accessory sexual gland - prostate, which produces vast portion of seminal plasma.(AU)

Influência das espécies reativas de oxigênio durante o cultivo in vitro de oócitos e folículos ovarianos de mamíferos domésticos / Influence of reactive oxygen species during in vitro culture of ovarian oocytes and follicles of domestic mammals

Sistemas de cultivo in vitro de folículos pré-antrais e de complexos cumulus-oócitos (CCOs) se tornaram uma poderosa ferramenta capaz de subsidiar diversas biotécnicas reprodutivas, bem como possibilitar estudos do efeito de substâncias sobre a dinâmica folicular. No entanto, esses sistemas podem resultar em estresse oxidativo e na diminuição da proteção antioxidante das células, distúrbio associado a altas taxas de morte celular durante o cultivo in vitro. Para contornar esses efeitos adversos, a adição de substâncias antioxidantes aos meios de cultivo tem sido proposta. Abrangendo diferentes classes e mecanismos de ação, compostos antioxidantes têm por função interferir no processo de oxidação para inibir ou retardar o dano oxidativo causado pelos radicais livres às biomoléculas. Além de antioxidantes que têm sido rotineiramente utilizados com esse propósito, recentemente, substâncias alternativas de origem natural como extratos vegetais e óleos essenciais têm ganhado destaque. Dessa forma, diante da influência do estresse oxidativo e da importância do uso de antioxidantes no cultivo celular, a presente revisão objetiva abordar os principais mecanismos de síntese e atuação dos radicais livres bem como o papel dos antioxidantes em protocolos de cultivo in vitro de folículos ovarianos e de CCOs de animais domésticos.(AU)

In vitro culture systems for preantral follicles and cumulus-oocyte complexes (COCs) have become a powerful tool capable of subsidizing several reproductive biotechniques, as well as enabling studies of the effect of substances on follicular dynamics. However, these systems can favor oxidative stress and decrease the antioxidant protection of cells, a disorder associated with high rates of cell death during in vitro culture. To overcome these adverse effects, the addition of antioxidant substances to the culture media has been proposed. Covering different classes and mechanisms of action, these antioxidant compounds have the function of interfering in the oxidation process to inhibit or delay the oxidative damage caused by free radicals to biomolecules. In addition to antioxidants that have been commonly used for this purpose, recently, alternative substances of natural origin such as plant extracts and essential oils have gained prominence. Thus, given the influence of oxidative stress and the importance of using antioxidants in cell culture, this review aims to address the main mechanisms of synthesis and action of free radicals as well as the role of antioxidants in in vitro protocols for ovarian follicles and COCs in domestic animals.(AU)

Avanços na andrologia de animais selvagens / Advances in wild animal andrology

As tecnologias de reprodução assistida (TRA) são de fundamental importância para a conexão de indivíduos em diferentes localidades, facilitando assim o intercâmbio genético e favorecendo a variabilidade genética de uma espécie. Por esta razão, as TRAS podem ser ferramentas importantes para a conservação de espécies ameaçadas de extinção. Apesar dos esforços nas últimas décadas, o avanço no desenvolvimento de tais tecnologias está aquém à urgência de reverter processos de baixa variabilidade genética em algumas espécies. A necessidade de refinamento das técnicas para as particularidades fisiológicas e comportamentais de cada espécie, somada à raridade de acesso aos animais são os principais fatores relacionados as dificuldades em se avançar com as TRAS. As técnicas mais recentes desenvolvidas para a recuperação de espermatozoides em animais selvagens são a colheita farmacológica, com uso de alfa-2-agonistas e a criopreservação / vitrificação testicular com posterior cultivo. Pouco de avançou, no entanto, em relação aos métodos de criopreservação, prevalecendo associação clássica de TRIS-gema-glicerol. Discutimos, então os métodos usados para acesso ao gameta masculino em espécies selvagens e suas aplicações na conservação animal.(AU)

Assisted reproduction technologies (ART) are of fundamental importance for connecting individuals in different locations, thus facilitating genetic exchange and favoring the genetic variability of a species. For this reason, TRAS can be important tools for the conservation of endangered species. Despite efforts in recent decades, the advance in the development of such technologies is short of the urgency of reversing processes of low genetic variability in some species. The need to refine the techniques for the physiological and behavioral particularities of each species, added to the rarity of access to animals, are the main factors related to the difficulties in advancing with TRAS. The most recent techniques developed for sperm collection in wild animals are pharmacological collection, with the use of alpha-2-agonists and testicular cryopreservation / vitrification with subsequent cultivation. Little progress has been made, however, in relation to cryopreservation methods, prevailing the classic association of TRIS-yolk-glycerol. We therefore discuss the methods used to access the male gamete in wild species and their applications in animal conservation.(AU)

The embryo culture media in the era of epigenetics: is it time to go back to nature?

This review is intended to draw attention to the importance of the culture media composition on the health of the embryos, fetuses, newborns, and adults derived from assisted reproductive technologies (ART). Although current research and industry trends are to use chemically defined media because of their suitability for manufacturing, commercialization, and regulatory purposes, compelling evidence indicates that those media fail to adequately account for the biological demands of early embryogenesis. Here, we list the main undesirable consequences of the ART described in the literature and results we and others have obtained over the past decade exploring an alternative and more natural way to support embryo growth in vitro: inclusion of endogenous reproductive fluids as additives in the ART culture media for pigs, cows, and humans. This review systematically assesses the pros and cons of using reproductive fluid additives, as well as the requirements to implement this approach in the future.(AU)