Relationships between follicle and corpus luteum size and vascularization with ovulation, progesterone production, and pregnancy in Nellore beef cattle

ABSTRACT The objective of this study was to evaluate the relationships between preovulatory follicle (POF) and corpus luteum (CL) diameters, and POF and CL vascular perfusion with progesterone production, ovulation, and pregnancy in Nellore cows subjected to timed artificial insemination (TAI). Nellore cows (n = 201) were subjected to ovulation synchronization and later to ultrasound evaluation of POF and CL at the time of insemination (D0) and seven days later (D7), respectively. Females were divided into three categories according to the POF diameter assessed at the time of insemination: small (SF), medium (MF), and large (LF) follicles. The LF group had a greater number and intensity of pixels in the POF ultrasound exam compared with the SF group. The CL flow intensity and progesterone concentration were also higher in the LF group. The SF group showed lower flow intensity and lower ovulation rate compared with the others. When non-pregnant females were compared to pregnant ones, no difference was observed in any of the analyzed variables. The results show for the first time in Nellore cattle the relationship between the size of ovarian structures and blood flow (quantity and intensity) as well as the ability of the CL to produce progesterone. The intensity of the POF pixels proved to be relevant, demonstrating correlations with the size and flow of the CL, which were not found when evaluating only the number of pixels, thus revealing the importance of evaluating complementary characteristics of the flow.

Interação da sazonalidade e nutrição na viabilidade embrionária ovina / Interaction between seasonality and nutrition on embrio viability of ovines

A sazonalidade reprodutiva e a condição nutricional são os principais fatores que influenciam o desempenho reprodutivo em ovinos, principalmente em áreas onde a disponibilidade de alimentos é altamente sazonal. A desnutrição pode comprometer a competência folículo-oocitária, a função lútea e o desenvolvimento embrionário. Por outro lado, o tratamento com melatonina é um método eficaz para induzir ciclicidade, aumentando a ovulação e melhorando a viabilidade do embrião durante o anestro. Portanto, levantamos a hipótese de que a melatonina pode substituir os efeitos prejudiciais da desnutrição para melhorar o desempenho reprodutivo em ovelhas. A este respeito, esta revisão enfoca os efeitos da interação entre melatonina e nutrição na viabilidade do embrião e resume a informação disponível sobre o efeito da melatonina exógena na viabilidade do embrião em ovelhas desnutridas.(AU)

Reproductive seasonality and nutritional condition are the main factors that influence reproductive performance in sheep, particularly in the areas where the availability of food is highly seasonal. Undernutrition can compromise follicle-oocyte competence, luteal function and embryo development. On the other hand, melatonin treatment is an effective method for inducing estrous cycles, increasing ovulation and improving embryo viability during anestrus. Therefore, we hypothesized that melatonin can override the detrimental effects of undernutrition to improve reproductive performance in ewes. In this regard, this review focuses on the effects of the interaction between melatonin and nutrition on embryo viability and summarizes the available information about the effect of exogenous melatonin on embryo viability in undernourished ewes.(au)

Investigation of Egg Weight, Ovarian Follicles Morphology and Growth Differentiation Factor 9 mRNA Expression in Potchefstroom Koekoek Chicken Breed

The growth differentiation factor 9 (GDF9) gene plays a vital role in the growth and maturation of ovarian follicles in laying hens. However, its messenger ribonucleic acid (mRNA) expression levels in preovulatory ovarian follicles of indigenous chickens remain poorly understood. The study aimed to identify the association between egg weight and egg quality traits, ovarian follicles morphology, and mRNA expression levels of the GDF9 gene in pre-ovulatory ovarian follicles of the South African Potchefstroom Koekoek chicken breed. The correlation results showed that egg weight (EW) had a positively high significant correlation (p<0.01) with egg width (EWD), yolk weight (YW), shell surface area (SSA), albumen weight (AW), albumen ratio (AR) and egg volume (EV), and a positive significant correlation (p<0.05) with egg length (EL). The Student's T-test results revealed that the numbers of large yellow follicles were significantly lower (p<0.05) than those of small yellow follicles. ANOVA findings showed that there was a significant difference (p<0.05) in the average weight of the large yellow follicles. The quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) findings indicated that there were significant differences (p<0.05) in the mRNA expression levels of the GDF9 gene in preovulatory ovarian follicles of the Potchefstroom Koekoek chicken breed. The mRNA expression was more abundant in F1 and F4 than in other ovarian follicles.(AU)

Uso da ultrassonografia Doppler colorido na reprodução de pequenos ruminantes / Use of color Doppler ultrasonography in the reproduction of small ruminants

A ultrassonografia (US) Doppler colorido fornece uma ferramenta não invasiva valiosa para detectar e monitorar mudanças dinâmicas na rede vascular e fluxo sanguíneo em vários órgãos e tecidos reprodutivos. Em apoio as biotécnicas da reprodução animal assistida, a US Doppler colorido tem mostrada alta eficiência no monitoramento funcional das estruturas ovarianas. A previsão de respostas ovarianas e produções embrionária em ovinos pela identificação de sinais Doppler na parede folicular já se mostrou eficiente. A aplicação da US Doppler colorido para a identificação da funcionalidade do tecido luteal é ainda maior, desde acompanhamentos fisiológicos e diagnósticos de disfunções luteais até ampla aplicação em conjunto as diferentes biotécnicas reprodutivas. Destaca-se em ovelhas e cabras, a aplicação comercial da US Doppler colorido para o diagnóstico de gestação precoce, de disfunções luteais, de determinação de respostas ovarianas em fêmeas doadoras e receptoras de embriões, para identificar efeitos luteotrófico de estratégias hormonais, e ainda para amparar as estratégias de ressincronização de estro.(AU)

Color Doppler ultrasonography (US) provides a valuable non-invasive tool for detecting and monitoring dynamic changes in the vascular network and blood flow in various reproductive organs and tissues. In support of assisted animal reproduction biotechniques, color Doppler US has shown high efficiency in the functional monitoring of ovarian structures. The prediction of ovarian responses and embryonic production in sheep by identifying Doppler signals in the follicular wall has already proved to be efficient. The application of color Doppler US for identifying the functionality of the luteal tissue is even greater, from physiological monitoring and diagnosis of luteal dysfunctions to wide application together with different reproductive biotechniques. It stands out in sheep and goats, the commercial application of color Doppler US for the diagnosis of early pregnancy, luteal dysfunctions, determination of ovarian responses in embryo donor and recipient females, to identify luteotrophic effects of hormonal strategies, and even to support estrus resynchronization strategies.(AU)

Dr Association of bone morphogenetic protein 15 and growth differentiation factor 9 with litter size in livestock: a review study

Litter size is one of the crucial factors in livestock production and is of high economic value, which is affected by ovulation rate, hormones, and growth factors.Growth factors play a multifaceted role in reproductive physiology. This review aims to investigate the association of bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9)with litter size in livestock.The transforming growth factor ß(TGF-ß) superfamily includes more than 34 members; GDF9 and BMP15 are among the most significantfactors for regulating fertility and litter size in most livestock species. Ovarian follicles release BMP15 and GDF9 that are involved in the maturation of primary follicles into the basal form, proliferation of granulosa and theca cells, steroidogenesis, ovulation, and formation of the corpus luteum. Besides, these factors are highly expressed in oocytes and are necessary for female fertility and multiple ovulation in several livestock species. Animals with two inactive copies of these factors are sterile, while those with one inactive copy are fertile. Thus, the present reviewprovides valuable information on the association of BMP15 and GDF9with litter size in livestock that can be used as biological markers of multiple ovulation or for improving fertility in livestock.(AU)

Distocia em tigre d'água-de-orelha-vermelha, Trachemys scripta elegans, wied (1839): relato de caso / Dystocia in red-eared slider, Trachemys scripta elegans, wied (1839): case report / Distocia en tortuga de orejas rojas, Trachemys scripta elegans, wied (1839): reporte de caso

Atualmente muitos répteis se tornaram animais de companhia e são mantidos como pet's exóticos. A espécie Trachemys scripta elegans, Wied (1839) é um animal exótico da América do Norte, sua identificação é realizada pelas marcas avermelhadas encontradas lateralmente a sua cabeça. Na rotina clínica as principais enfermidades que acometem os quelônios são as de origem reprodutiva, como a estase folicular e distocia. O objetivo deste trabalho foi relatar um caso recorrente de distocia em um tigre d'água fêmea, para isso, a anamnese, o histórico da paciente, e seus sinais clínicos, em conjunto com os exames complementares de imagem foram essenciais para se obter diagnóstico definitivo. O tratamento foi realizado com a indução medicamentosa utilizando borogluconato de cálcio, seguida da aplicação de ocitocina, esta trouxe resultados positivos para a eliminação dos ovos. Porém devido ao histórico do paciente, optou-se pela intervenção cirúrgica de ovariossalpingectomia, sendo está a maneira permanente de resolução da patologia. O protocolo terapêutico escolhido proporcionou um resultado satisfatório e bem estar ao animal.(AU)

Currently, many reptiles have become companion animals and are kept as exotic pets. The species Trachemys scripta elegans, Wied (1839) is an exotic animal from North America, and its identification is based on the reddish markings found laterally on its head. In routine clinical practice, the main diseases that affect chelonians are those of reproductive origin, such as follicular stasis and dystocia. The aim of this study was to report a recurrent case of dystocia in a female red-eared slider turtle. For this purpose, the patient's anamnesis, history, and clinical signs, along with complementary imaging exams, were essential to obtain a definitive diagnosis. The treatment involved medical induction using calcium borogluconate, followed by the administration of oxytocin, which yielded positive results in egg elimination. However, due to the patient's history, surgical intervention in the form of ovariosalpingectomy was chosen as the permanent solution to the pathology. The chosen therapeutic protocol provided a satisfactory outcome and improved the animal's well-being.(AU)

Actualmente muchos reptiles se han convertido en animales de compañía y se mantienen como mascotas exóticas. La especie Trachemys scripta elegans, Wied (1839) es un animal exótico de América del Norte, su identificación se realiza por las marcas rojizas que se encuentran lateralmente a su cabeza. En la rutina clínica, las principales enfermedades que afectan a los quelonios son las de origen reproductivo, como la estasis folicular y la distocia. El objetivo de este trabajo fue reportar un caso recurrente de distocia en una hembra de tigre de agua, para ello la anamnesis, la historia de la paciente y sus signos clínicos, junto con los exámenes imagenológicos complementarios fueron fundamentales para obtener un diagnóstico definitivo. El tratamiento se realizó con inducción farmacológica con borogluconato de calcio, seguido de la aplicación de oxitocina, que arrojó resultados positivos con la eliminación de huevos. Sin embargo, debido a los antecedentes de la paciente, se optó por la intervención quirúrgica de ovarialpingectomía, que es la forma definitiva de resolución de la patología. El protocolo terapéutico elegido proporcionó un resultado satisfactorio y bienestar al animal.(AU)

Importance of preovulatory estradiol on uterine receptivity and luteal function

Animals that exhibited estrus had greater pregnancy success compared to animals that did not exhibit estrus before fixed-time AI (FTAI). Estradiol is synthesized in bovine ovarian follicles under gonadotropin regulation and can directly and indirectly regulate the uterine receptivity and luteal function. Estradiol concentrations at FTAI impacted oviductal gene expression and has been reported to play an important role in establishing the timing of uterine receptivity. These changes have been reported to impact uterine pH and sperm transport to the site of fertilization. After fertilization, preovulatory estradiol has been reported to improve embryo survival likely by mediating changes in uterine blood flow, endometrial thickness and changes in histotroph. Cows with greater estradiol concentrations at the time of GnRH-induced ovulation also had a larger dominant follicle size and greater circulating progesterone concentrations on day 7. Therefore, it is impossible to accurately determine the individual benefit of greater estradiol concentrations prior to ovulation and greater progesterone concentrations following ovulation to pregnancy establishment, as these two measurements are confounded. Research has indicated an importance in the occurrence and timing of increasing preovulatory concentrations of estradiol, but increasing estradiol concentrations by supplementation may not be sufficient to increase fertility. Increased production of estradiol by the preovulatory follicle may be required to enhance fertility through the regulation of sperm transport, fertilization, oviductal secretions, the uterine environment, and embryo survival.(AU)

Pilomatricoma benigno em cão da raça Shih-Tzu / Benign pilomatricoma in a Shih-Tzu dog

Background: Pilomatricomas are neoplasms of hair follicles, located in the hair bulb, and the incidence is uncommon in the clinical-surgical clinical routine of dogs and cats. It commonly affects adult animals, with no predisposition to sex or race, and is mainly located in the neck, back, and tail region. The diagnosis is made by histopathological examination, where cells are observed in which their nucleus does not stain with hematoxylin and eosin - empty nucleus. The present work aimed to report a case of benign pilomatricoma since it is a rare condition in dogs and cats and, consequently, there is little information in the literature. Case: A 6-year-old male Shih-Tzu dog, not submitted to surgical contraception, weighing 6.9 kg, was treated at the Veterinary School Hospital (HVE) of the North Parana State University (UENP), Bandeirantes, PR, Brazil, with a history of nodules in the tail region, lasting 6 months. On physical examination, no changes were identified in the patient's physiological parameters. However, the presence of neoformations in the distal and medial region of the tail, similar to a nail, adherent, non-ulcerated and non-alopecic, and absence of pruritus or self-mutilation were identified. Vaccination and deworming were updated. Hematological examination, serum biochemicals (urea, creatinine, alanine aminotransferase, alkaline phosphatase, and albumin), and abdominal ultrasound showed no changes. According to the clinical and laboratory signs, it was decided to perform an excisional biopsy, using a caudectomy, for subsequent histopathological examination. The specimens were fixed in 10% formaldehyde and sent for histopathological examination. Histological examination was compatible with benign pilomatricoma. Postoperatively, cephalexin, dipyrone, tramadol hydrochloride, and meloxicam were prescribed, surgical wound cleaning, and the use of an Elizabethan collar until the suture was removed. After 10 days of the surgical procedure, the patient was asked to remove the sutures, and no changes were identified regarding the physiological parameters and blood count. Discussion: Pilomatricomas are commonly benign neoplasms arising from the germ cells of the follicular matrix. They present dermal or subdermal forms, with several cystic structures which are surrounded by keratinocytes, similar to the matrix cells of an anagen hair follicle, more keratinized and firmer areas, corroborating the results of the present report. In the ultrasound examination, the presence of intra-abdominal metastases was not identified, which is consistent with the literature, since in this type of neoplasm it is not common to identify foci of intra-abdominal and thoracic metastases. In the present report, immunohistochemistry was not used, even though it is used to differentiate follicular neoplasms from pilomatricomas. However, histopathological examination is considered the best method for the definitive diagnosis of pilomatricomas in dogs. It was concluded that the surgical treatment through excisional biopsy, with safety margins of 2 cm, was effective as a therapeutic method in the case of benign pilomatricoma, and the definitive diagnosis must be made through histopathological examination.

Warty Dyskeratoma with involvement of multiple hair follicles in a dog

The warty dyskeratoma is a neoplasm of follicular origin, with uncommon incidence in veterinary medicine, and benign biological behavior. An excisional biopsy sample was received from a dog, female, Shih Tzu, 12 years old, from the left axillary region. Grossly, after section, green and friable multifocal areas were identified, streaked by solid white areas. Microscopically, the analysis revealed multifocal cystic structures, lined by stratified epithelium, with basal area including villous epithelial projections, toward the dermis, and the luminal region featured acantholysis and dyskeratosis, as well as parakeratosis. Those findings were compatible with a warty dyskeratoma affecting multiple hair follicles, thus being the first case report in veterinary medicine with such this unique pattern. Up to now, the literature encompassed only human medicine. This report, besides collaborating to the description of a rare presentation of an uncommon neoplasm, also contributes with new information found for epidemiological studies of this tumor.(AU)

Oxidative activity of corpus luteum and ovarian parenchyma in Bos taurus indicus heifers

Abstract The aim of this study was to evaluate the oxidative stress in ovaries and corpus luteum (CL) of Bos taurus indicus females and the oxidant effect of CL in ovarian tissues in regions near, intermediate, or distant from it. Ovaries (n=12) of Nelore heifers (n=6) were collected from a slaughterhouse and fragmented. Experiment 1, each ovary was obtained from three fragments, resulting in 18 fragments of ovaries with CL (OV+CL) and another 18 fragments of ovaries without CL (OV-CL). Three fragments were generated from CL, totaling 18 CL fragments. In experiment 2, the ovarian fragments were removed from specific regions near, intermediate, or distant from the CL. All the fragments were placed in Eppendorf-type microtubes (1 mL), kept in a thermal container at 4 ºC, and then stored in a -80 ºC freezer for analysis of oxidative stress (TBARS and NBT) and antioxidant potential (FRAP and ABTS). In the antioxidant activity analysis, luteal tissues showed more antioxidant activity than ovarian tissue (FRAP = P < 0.0001; ABTS = P < 0.02). In the oxidative stress analysis, CL had lower levels of reactive oxygen species (ROS; TBARS = P < 0.03; NBT = P < 0.0001) than ovarian tissues. There was no difference in antioxidant activity and oxidative stress between the fragments obtained from different regions (OV+CL versus OV-CL; P > 0.05). The presence of CL in the ovaries of Bos taurus indicus females did not influence the oxidative stress or antioxidant potential of the gonad. Thus, the removal of ovarian fragments with or without the presence of CL indicates that biotechnologies such as in vitro follicle cultivation is possible.

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)

Biochemical and immunohistochemical examination of the effects of ephedrine in rat ovary tissue

Purpose: It was aimed to investigate the biochemical and immunohistochemical effects of ephedrine (EPH) in bilateral ovariectomized rats. Methods: Twenty-four Sprague Dawley female rats were divided into three groups: control group: The abdomen was opened and closed without any treatment; ischemia-reperfusion (IR) group: 2 h of ischemia followed by 2 h of reperfusion were allowed to cause IR injury; IR+EPH group: oral EPH solution (5 mg/kg) was administered for 28 days. Results: Biochemical parameters were statistically significant in group comparisons. Increased interleukin-6 (IL-6) expression, degenerative preantral and antral follicle cells and inflammatory cells around blood vessels were seen in IR group. Negative IL-6 expression was observed in seminal epithelial cells, preantral and antral follicle cells in IR+EPH group. While caspase-3 activity increased in granulosa cells and stromal cells in IR group, caspase-3 expression was negative in preantral and antral follicle cells in the germinal epithelium and cortex in IR+EPH group. Conclusion: The effect of apoptosis, which occurs with the signaling that starts in the cell nucleus, caused the cessation of the stimulating effect at the nuclear level after EPH administration, and a decrease in the antioxidative effect in IR damage and inflammation in the apoptotic process.

Antral follicle count classification selects fertile heifers without influencing the carcass traits / A classificação da contagem folicular antral seleciona novilhas mais férteis sem influenciar as características da carcaça

This study aimed to evaluate the ovarian structure, estrus intensity, ultrasound carcass measurements, and pregnancy rate of Nelore breed heifers and cows in accordance with antral follicle counts (AFCs). We evaluated 503 heifers and 565 Nelore cows, with a mean age of 15.5±2.2 and 69.8±36.1 months, respectively, submitted to a fixed-time artificial insemination (FTAI) protocol. On day zero, all bovine females were examined using ultrasound to determine the AFC. The mean AFC of the heifers and cows were 20±8.6 and 22.5±8.4, respectively. The rib-eye area (REA) and fat thickness (FT) of the heifers (n = 119 for REA and n = 219 for FT) were measured using ultrasound imaging. The average conception rates at the first FTAI and at the end of the breeding season were 35.8% and 57.5%, respectively, for heifers and 45.1% and 78.9%, respectively, for cows. We demonstrated that the probability of pregnancy at the first FTAI and at the end of the breeding season for both young heifers and cows increased as the AFC decreased (P>0.001 and P=0.0123, respectively). FT and REA showed no correlation with AFC in heifers. The intensity of estrus expression was negatively correlated with AFC (−0.46; P<0.0001). In conclusion, Nelore heifers and cows with low AFC had a high probability of pregnancy during the entire breeding season. Thus, AFC can be used as a tool to select heifers with increased fertility without affecting carcass traits (REA and FT).

Este estudo teve como objetivo avaliar as estruturas ovarianas, intensidade do cio, medidas de carcaça por ultrassonografia e taxa de gestação de novilhas e vacas da raça Nelore com diferentes contagens de folículos antrais (CFA). Avaliamos 503 novilhas e 565 vacas Nelore, com idade média de 15,5 ± 2,2 e 69,8 ± 36,1 meses, respectivamente, submetidas a um protocolo de inseminação artificial em tempo fixo (IATF). No dia zero, todas as fêmeas foram examinadas por ultrassom para determinar a CFA. A CFA média das novilhas foi de 20 ± 8,6 e a das vacas foi de 22,5 ± 8,4 folículos. A área de olho de lombo (AOL) e a espessura de gordura (EG) das novilhas (n = 119 para AOL e n = 219 para EG) foram medidas utilizando imagens ultrassonográficas. As taxas médias de concepção na primeira IATF e no final da estação de monta foram de 35,8% e 57,5% e 45,1% e 78,9% para as novilhas e vacas, respectivamente. Demonstramos que a probabilidade de gestação na primeira IATF e no final da estação de monta, tanto para novilhas jovens quanto para vacas, foi maior quando a CFA era menor (P>0,001 e P=0,0123, respectivamente). A espessura da gordura e a AOL não mostraram nenhuma correlação com a CFA. A intensidade da expressão do cio foi negativamente correlacionada com o CFA (-0,46; P < 0,0001). Em conclusão, novilhas jovens e vacas da raça Nelore com menor CFA apresentam maior probabilidade de prenhez durante toda a estação de monta. Nenhuma relação entre a CFA e as características de carcaça foram observadas em novilhas Nelore. A CFA pode ser usada como uma ferramenta de seleção de novilhas com maior fertilidade sem influenciar as características de carcaça (AOL e EG).

Oxidative activity of corpus luteum and ovarian parenchyma in Bos taurus indicus heifers

The aim of this study was to evaluate the oxidative stress in ovaries and corpus luteum (CL) of Bos taurus indicus females and the oxidant effect of CL in ovarian tissues in regions near, intermediate, or distant from it. Ovaries (n=12) of Nelore heifers (n=6) were collected from a slaughterhouse and fragmented. Experiment 1, each ovary was obtained from three fragments, resulting in 18 fragments of ovaries with CL (OV+CL) and another 18 fragments of ovaries without CL (OV-CL). Three fragments were generated from CL, totaling 18 CL fragments. In experiment 2, the ovarian fragments were removed from specific regions near, intermediate, or distant from the CL. All the fragments were placed in Eppendorf-type microtubes (1 mL), kept in a thermal container at 4 ºC, and then stored in a -80 ºC freezer for analysis of oxidative stress (TBARS and NBT) and antioxidant potential (FRAP and ABTS). In the antioxidant activity analysis, luteal tissues showed more antioxidant activity than ovarian tissue (FRAP = P < 0.0001; ABTS = P < 0.02). In the oxidative stress analysis, CL had lower levels of reactive oxygen species (ROS; TBARS = P < 0.03; NBT = P < 0.0001) than ovarian tissues. There was no difference in antioxidant activity and oxidative stress between the fragments obtained from different regions (OV+CL versus OV-CL; P > 0.05). The presence of CL in the ovaries of Bos taurus indicus females did not influence the oxidative stress or antioxidant potential of the gonad. Thus, the removal of ovarian fragments with or without the presence of CL indicates that biotechnologies such as in vitro follicle cultivation is possible.(AU)

Effect of castration and vasectomy on some oxidative stress parameters and blood hormone levels in rats / Efeito da castração e da vasectomia em alguns parâmetros de estresse oxidativo e níveis de hormônios no sangue

Vasectomy and castration are the most preferred surgical methods to control reproduction in males. While sexual functions are terminated reversibly in vasectomy, they are removed irreversibly in castration. After these processes, changes are observed in hormones and oxidative stress parameters. In this study, we investigated the effects of vasectomy and castration operations on blood follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, nitric oxide (NO) and malondialdehyde (MDA) levels in rats. As a result of the analysis, it was determined that FSH, LH, NO, and MDA levels increased (p<0.05) and testosterone levels decreased (p<0.05) in the castration group compared to the sham and vasectomy groups. Considering the data obtained from the present study, when the two operations (vasectomy and castration) are compared in rats, which are preferred for the control of reproduction, it is thought that vasectomy is a healthier method because it is reversible, does not affect hormone levels, and does not increase oxidative stress.

A vasectomia e a castração são os métodos cirúrgicos preferidos para controlar a reprodução no sexo masculino. Enquanto as funções sexuais terminam reversivelmente na vasectomia, elas são removidas irreversivelmente na castração. Após esses processos, são observadas alterações nos hormônios e nos parâmetros de estresse oxidativo. Neste estudo, foram investigados os efeitos das operações de vasectomia e castração nos níveis sanguíneos de hormônio folículo estimulante (FSH), hormônio luteinizante (LH), testosterona, óxido nítrico (NO) e malondialdeído (MDA) em ratos. Como resultado da análise, foi determinado que os níveis de FSH, LH, NO e MDA aumentaram (P<0,05) e os níveis de testosterona diminuíram (P<0,05) no grupo de castração em comparação com os grupos sham e vasectomia. Considerando os dados obtidos no presente estudo, quando comparadas as duas operações (vasectomia e castração) em ratos, preferidas para o controle da reprodução, acredita-se que a vasectomia é um método mais saudável por ser reversível, não afetar os níveis hormonais e não aumentar o estresse oxidativo.

The waveless model: clinical and research applications of follicular wave suppression in cattle / Modelo waveless: aplicações clínicas e na pesquisa da supressão das ondas foliculares em bovinos

The follicular growth waves are directly linked to the fluctuations in plasma gonadotrophins, which are controlled by the hypothalamic GnRH release pattern. Therefore, if the actions of the GnRH are inhibited or blocked, the final stages of the antral follicle growth are suppressed, resulting in an induced anestrus (a.k.a. waveless model). In the human medicine, GnRH agonists or antagonists are broadly used in the control of ovarian disfunctions, as well as in the preparation of women for assisted reproductive cycles. In cattle, a similar effect can be obtained by active immunization against GnRH. This was shown to be a viable strategy, for example, for the control of chronic cases of cystic ovarian disease in oocyte donors. However, on shall take into account the substantial individual variation on the immune response and, consequently, the lack of control of the duration of the anestrus induced. The waveless model is also very useful as a research model, once it controls the potential interference of the endogenous FSH and LH, improving the sensitivity of essays with exogenous hormones and consequently reducing the required number of replicas within studies.(AU)

O padrão de crescimento folicular em ondas está diretamente associado às flutuações nas concentrações plasmáticas de gonadotrofinas, controladas por sua vez pelo padrão de liberação de GnRH hipotalâmico. Desta forma, a inibição ou bloqueio da ação do GnRH suprime as etapas finais do crescimento folicular, resultando em anestro induzido (também chamado modelo waveless). Na medicina humana, agonistas ou antagonistas de GnRH são utilizados tanto no controle de disfunções ovarianas quanto na preparação de pacientes para procedimentos de reprodução assistida. Em bovinos, este efeito pode ser obtido pela imunização ativa contra GnRH, e mostrou-se estratégia viável, por exemplo, no controle de casos crônicos de doença ovariana cística em doadoras de oócitos. Contudo, é importante considerar a grande variação individual na resposta à imunização e consequente impossibilidade de controlar a duração do anestro induzido. O modelo waveless também é de grande utilidade na pesquisa, uma vez que elimina a potencial interferência do FSH e LH endógenos, aumentando a sensibilidade nos ensaios com hormônios exógenos e consequentemente reduzindo o número de réplicas necessárias nos estudos.(AU)

Estudos para o incremento da produção de embriões in vivo e in vitro em vacas de corte taurinas e sintéticas / Studies to improve in vivo and in vitro embryo production in beef cows from taurine and synthetic breeds

O Brasil destaca-se por ser um dos líderes mundiais na produção in vitro de embriões, o que é decorrente do rebanho nacional ser predominantemente composto por raças zebuínas, que possuem maior número de folículos antrais aspiráveis. Por outro lado, vacas taurinas apresentam menor população folicular antral, o que limita o número de ovócitos obtidos por seção de aspiração folicular (ovum pick-up; OPU). Portanto, na região Sul do Brasil há demanda para produção tanto in vivo como in vitro de embriões de doadoras de raças taurinas e sintéticas. Este texto discute estudos recentes que buscam estratégias para aperfeiçoar as etapas envolvidas na produção de embriões bovinos, bem como para aumentar o aproveitamento de receptoras utilizadas nos programas de transferência de embriões (TE), com foco em vacas taurinas e sintéticas.(AU)

Brazil stands among the leaders on in vitro embryo production, as the Brazilian herd is predominantly composed by Zebu breeds, which have a greater number of antral follicles available to ovum pick-up (OPU). On the other hand, taurine cows have a lower antral follicle population, which limits the number of oocytes obtained by each OPU section. Therefore, in the Brazilian Southern region there is a demand for both in vivo and in vitro production of embryos from donors of taurine and synthetic breeds. This text discusses recent studies that seek strategies to improve the steps involved in the production of bovine embryos, as well as to increase the use of recipients in embryo transfer (ET) programs, focusing on taurine and synthetic cows.(AU)

Lipopolysaccharide effects on activation and apoptosis of primordial ovarian follicles in heifers / Efeitos de lipopolissacarídeos na ativação e apoptose de folículos ovarianos primordiais em novilhas

The objective of the present study was to evaluate the effect of lipopolysaccharide (LPS) administration on activation and apoptosis of primordial follicles. There was no difference in the total number of follicles as well as in the different types of follicles. Furthermore, the LPS challenge didn't modulate the expression of genes related with ovarian reserve (HAM), oocyte survival (Survivin), activation rate (Pten, KIT, KITL1, KITL2, AKT1, SIRT1), and follicular abnormalities. Therefore, the LPS exposure with 24h interval had no effect on activation rate and primordial follicles abnormalities, and also had no effect on expression of anti-apoptotic genes and genes related with ovarian reserve, oocyte survival, activation rate, and primordial follicles abnormalities.

O objetivo do presente estudo foi avaliar o efeito da administração de lipopolissacarídeo (LPS) na ativação e a apoptose de folículos primordiais. Dez novilhas saudáveis (Bos taurus taurus), com idade média de 14 meses, alojadas em sistema de confinamento e alimentadas com TMR, foram utilizadas neste experimento. Os animais foram distribuídos aleatoriamente em dois grupos: grupo LPS (LPS; n = 5), que recebeu duas injeções intravenosas de 0,5µg/kg de peso corporal de lipopolissacarídeo (Sigma Aldrich®) diluído em 2mL de solução salina (0,9% de NaCl), com intervalo de 24h; e grupo controle (CTR; n = 5), que recebeu duas injeções intravenosas de 2mL de solução salina (0,9% de NaCl), com intervalo de 24h. A primeira injeção de LPS foi realizada no d 1, e no d 5 os animais foram abatidos, os ovários foram pesados e as amostras dos ovários foram coletadas para avaliação histológica e molecular. Não houve diferença no número total de folículos, bem como nos diferentes tipos de folículos. Além disso, o desafio com LPS não modulou a expressão de genes relacionados à reserva ovariana (HAM), à sobrevivência oocitária (Survivin), à taxa de ativação (Pten, KIT, KITL1, KITL2, AKT1, SIRT1) e às anormalidades foliculares. Portanto, a exposição ao LPS com intervalo de 24h não teve efeito sobre a taxa de ativação e as anormalidades dos folículos primordiais, bem como não teve efeito sobre a expressão de genes antiapoptóticos e de genes relacionados com a reserva ovariana, a sobrevivência oocitária, a taxa de ativação e as anormalidades dos folículos primordiais.

In vitro culture of red-rumped agouti preantral follicles enclosed in fresh and vitrified ovarian tissues using TCM199 plus different pFSH concentrations

Considering the relevance of establishing biodiversity conservation tools, the study aimed to investigate the TCM199 supplemented with different follicle-stimulating hormone (FSH) concentrations on survival and development of fresh and vitrified preantral follicles enclosed in red-rumped agouti ovarian tissues cultured in vitro. In the first experiment, six pairs of ovaries were fragmented and cultured for 6 days according to groups: 10 ng/mL pFSH (FSH10 group) and 50 ng/mL (FSH50 group). Non-cultured tissues were considered as a control. In the second experiment, vitrified/warmed fragments of four pairs of ovaries were cultured with the best concentration of FSH established (cryopreserved and cultured group). Non-cryopreserved (fresh control group) and cryopreserved but non-cultured (non-cultured group) tissues were used as controls. For both experiments, preantral follicles were evaluated for survival and development using morphological and viability analysis by trypan blue staining. After culturing fresh samples, FSH50 showed a higher percentage of morphologically normal follicles when compared to FSH10 (P < 0.05). This same response was observed for primordial follicles. Regardless of the concentrations of FSH used during in vitro culture, no difference was observed regarding the percentage of viable follicles and diameters (P > 0.05). Thus, the FSH50 group was used for second experiment, in which 76.2 ± 7.2% normal preantral follicles previously vitrified was found after 6-day culture, also presenting the highest values (P < 0.05) for morphology of primordial follicles (95.2 ± 4.7%). Nevertheless, in vitro culture did not affect the viability and diameter of preantral follicles of cryopreserved tissues (P > 0.05). In conclusion, TCM199 supplemented with 50 ng/mL FSH was efficient in maintaining the in vitro survival of fresh and vitrified red-rumped agouti preantral follicles. This was the first study related to the in vitro culture of ovarian preantral follicles in this species, aiming to contribute to its conservation.(AU)

Distiquíases em gatos / Distichiasis in cats

Background: Distichiasis is a disease that is rare in cats, but very common in dogs. The term distichiasis may be controversial when used in the feline species, given that they do not possess true cilia, but rudimentary hair along the superior palpebra. The patients may be asymptomatic, though some show signs of ocular discomfort and ulcerative keratitis. The diagnosis is reached through an ophthalmological exam, and the treatment consists of the removal of the cilium with or without its hair follicle. With this work, we aim to report a series of cases of distichiasis in cats, as it is an uncommon anomaly, and has the potential to cause ocular discomfort in cats. Cases: Two mobile services of veterinary ophthalmology, one in the federal district of Brasília (DF) and the other in the municipality of Valinhos (SP), attended to 9 cats over a period of 5 years (2018 to 2022). The cats (n = 9) attended are of an undefined breed with ages varying from 10 months to 9 years, with an average of 3.9-year-old. The number of distichiasis presented by the animals was classified according to their quantity, being categorized as a mild grade when there was a single cilium, moderate grade when there were 2 to 4 cilia, and severe grade when there were more than 5 cilia. The highest incidence of distichiasis in this study was in males (78%) while females accounted for (22%) of the cases. The clinical changes reported by the owners consisted of signs of ocular discomfort (photophobia, blepharospasm, and periocular itching), ocular discharge and ocular redness. In the ophthalmological evaluations, blepharospasm (22%), serous to mucosal secretion (56%), chemosis (22%), mild (44%) to moderate (11%) conjunctival hyperemia, and ulcerative keratitis (22%) were observed. Distichiasis was more frequent affecting both eyes (56%), while in only (44%) of cases it affected the left eye only. The highest occurrence of cilia was identified in the upper palpebra (78%). Distichiasis was found more often in the temporal palpebral portion (78%), and in 2 patients the identification was more challenging since these cilia lack pigmentation. Single cilium affected (44%) of patients, while 5 cats had multiple distichiasis (56%). A total of 29% of the cats had a mild grade, whereas 14% had a moderated grade, and 57% had a severe grade. The treatments performed consisted of manual epilation (ME) and electroepilation (EE). ME was carried out in 56% of the cats, with relapses occurring in 80% of the patients, while 44% of the cats submitted to EE had a relapse in 20% of the cases. Discussion: Distichiasis is an inherited disorder very frequent in dogs, but considered uncommon in cats. Its causative factor is still unknown, as is its mode of inheritance. In distichiasis therapy, epilation, electroepilation, electrolysis, diode laser, cryotherapy and surgical palpebral resection techniques are referred to as procedures. Among the treatments used in this study, we observed a lower incidence of relapse with the electroepilation technique, which proved to be a viable and successful therapeutic modality. This series of cases shows that perhaps this disorder is much more frequent than what has been reported in the literature, being sometimes underdiagnosed and consequently underreported. Therefore, distichiasis in cats should be considered as a differential diagnosis in patients with clinical signs of ocular discomfort and ulcerative keratitis.