Atualizações no controle do ciclo estral em ovinos / Updates on the control of the estrous cycle in sheep

Nos últimos anos, observou-se um aumento no tamanho do rebanho ovino no país, indicando uma retomada na ovinocultura. Para melhorar a eficiência reprodutiva desses animais, a utilização de biotécnicas tem se mostrado uma ferramenta importante. Dentre essas biotécnicas, destacam-se os protocolos de sincronização do ciclo estral, os quais frequentemente utilizam progesterona associada a gonadotrofinas ou análogos da prostaglandina em duas aplicações. Este artigo tem como objetivo revisar os protocolos de sincronização utilizados em ovinos e apresentar atualizações relevantes sobre os mesmos.(AU)

In recent years, there has been an increase in the size of the sheep herd in the country, indicating a recovery in sheep farming. To improve the reproductive efficiency of these animals, the use of biotechniques has been shown to be an important tool. Among these biotechniques, estrous cycle synchronization protocols stand out, which frequently use progesterone associated with gonadotropins or prostaglandin analogues in two applications. This article aims to review the synchronization protocols used in sheep and present relevant updates about them.(AU)

Efeito da progesterona na sincronização de vacas de leite / Effect of progesterone on synchronization of dairy cows

Diversos fatores impactam os índices reprodutivos em vacas leiteiras, como a produção de leite, o manejo nutricional e o programa reprodutivo implementado. Em vacas leiteiras de alta produção, o maior catabolismo de esteróides, como a progesterona, devem ser levados em consideração ao escolher o tratamento hormonal a ser realizado. Assim, estratégias com a suplementação de progesterona previamente e ao início do protocolo foram desenvolvidas e descritas.(AU)

Milk production, nutritional management and the implemented reproductive program impact reproductive rates in dairy cows. The greater catabolism of steroids such as progesterone in high producing dairy cows must be considered when choosing the hormonal treatment to be used. Thus, strategies with progesterone supplementation before and at the beginning of the protocol were developed and described.(AU)

Full confluency, serum starvation, and roscovitine for inducing arrest in the G0/G1 phase of the cell cycle in puma skin-derived fibroblast lines

The puma population is constantly decreasing, and cloning by somatic cell nuclear transfer can be used to conserve the species. One of the factors determining the success of the development of cloned embryos is the cell cycle stage of the donor cells. We evaluated the effects of full confluency (~100%), serum starvation (0.5% serum), and roscovitine (15 µM) treatments on the cell cycle synchronization in G0/G1 of puma skin-derived fibroblasts by flow cytometric analysis. Also, we assessed the effects of these synchronization methods on morphology, viability, and apoptosis levels using microscopy tools. The results showed that culturing the cells to confluence for 24 h (84.0%), 48 h (84.6%), and 72 h (84.2%) and serum starvation for 96 h (85.4%) yielded a significantly higher percentage of cells arrested in the G0/G1 (P < 0.05) phase than cells not subjected to any cell cycle synchronization method (73.9%). Nevertheless, while serum starvation reduced the percentage of viable cells, no difference was observed for the full confluence and roscovitine treatments (P > 0.05). Moreover, roscovitine for 12 h (78.6%) and 24 h (82.1%) was unable to synchronize cells in G0/G1 (P > 0.05). In summary, full confluency induces puma fibroblast cell cycle synchronization at the G0/G1 stage without affecting cell viability. These outcomes may be valuable for planning donor cells for somatic cell nuclear transfer in pumas.(AU)

Farmacopuntura em protocolos de sincronização de estro em pequenos ruminantes / Pharmacopuncture in estrus synchronization protocols in small ruminants

O objetivo com essa revisão foi realizar o levantamento da produção científica disponível e articular saberes a respeito do uso da farmacopuntura associada à protocolos de sincronização de estro principalmente em caprinos e ovinos, como também, em outras espécies de interesse. Ao analisar as pesquisas realizadas nos últimos 10 anos com a utilização de subdoses hormonais associada à farmacopuntura em programas de inseminação artificial em tempo fixo (IATF), nota-se que a farmacopuntura vem se tornando uma ferramenta promissora para viabilizar a redução das doses hormonais administradas e potencializar o efeito do fármaco aplicado, o que eleva a eficiência dos programas de sincronização de estro/ovulação ao reduzir os custos desses protocolos. Além de diminuir o custo desses protocolos para os produtores, nosso grupo de pesquisa realizou uma série de estudos nessa área, visando a busca por protocolos com menores doses hormonais, o que consequentemente reduz a quantidade de resíduos produzidos e promove manejos mais sustentáveis. Baseado nas publicações, pode-se afirmar que a farmacopuntura apresenta resultados satisfatórios e coloca-se como uma via de aplicação de sub-doses ou micro-doses hormonais em protocolos de controle do ciclo estral em caprinos e ovinos, como também, para outras espécies domésticas.(AU)

The objective of this review was to compile information regarding the use of pharmacopuncture associated with estrus synchronization protocols, mainly in goats and sheep, as well as in other species of interest, with the aim of updating and providing information on the subject. When analyzing the research carried out in the last 10 years with the use of hormonal underdoses associated with pharmacopuncture in fixed-time AI programs, these have become a promising tool to enable the reduction of administered hormonal doses and to potentiate the effect of the applied drug, the that increases the efficiency of estrus/ovulation synchronization programs by reducing the costs of these protocols. In addition to reducing the cost of these protocols for producers, our research group carried out a series of studies in this area, aiming at the search for protocols with lower hormonal doses, less waste produced and more sustainable management. Based on the publications, it can be stated that pharmacopuncture presents satisfactory results and is a way of applying sub-doses or micro-doses of hormones in protocols for controlling the estrous cycle in goats and sheep, as well as for other domestic species.(AU)

Recent advances in treatments for resynchronization of ovulation in small ruminants: a review

Hormonal methodologies to control small ruminants' estrous cycle are worldwide used and evolved, adjusting the application to the precise female physiological moments to enhance reproductive performance. The estrous cycle can be induced and/or synchronized, aiming for fixed-time artificial insemination, or based on estrus behavior signs for insemination, natural or guided mating. Successive protocols can be performed to resynchronize ovulation and increase reproductive outcomes in females that failed to conceive. These recently developed treatments aim to resynchronize the ovulation as earlier as non-pregnancy is detected. The present review aimed to summarize the recent advances and main findings regarding resynchronization protocols used in small ruminants. Lastly, we present future perspectives and new paths to be studied in the subject. The resynchronization treatment is still a growing field in small ruminant reproduction, nevertheless, some enhancements are found in the reproductive outcome, showing that such protocols can be successfully used in sheep and goat production.(AU)

Fatores que impactam na eficiência reprodutiva de vacas de corte / Factors that impact the reproductive efficiency of beef cows

A maior produtividade na pecuária está correlacionada com a eficiência reprodutiva do rebanho. As biotécnicas da reprodução, principalmente os protocolos de sincronização da ovulação, são de grande importância para otimizar a produção e acelerar o ganho genético em rebanhos de corte e de leite. No entanto, alguns fatores como a categoria animal, o manejo reprodutivo implementado na propriedade e o reprodutor utilizado podem afetar os resultados de fertilidade nos protocolos de IATF. Dessa maneira, algumas estratégias foram desenvolvidas para contornar alguns desafios inerentes a vacas de corte em anestro pós-parto e aumentar a eficiência reprodutiva dessas fêmeas. Dentre as estratégias, destacam-se a utilização de progesterona e a suplementação energética/proteica previamente ao início do protocolo de IATF.(AU)

The reproductive efficiency of the herd is correlated with higher productivity in livestock. Reproduction biotechniques as ovulation synchronization protocols are important to optimize production and accelerate genetic profit in beef and dairy herds. However, some factors such as the animal category, the reproductive management implemented on the farm and the sire used can affect the fertility results in the TAI protocols. In this way, some strategies were developed to overcome some challenges of postpartum anestrus beef cows and to increase the reproductive efficiency of these cows. The use of progesterone and energy/protein supplementation before starting the TAI protocol stand out are the strategies.(AU)

Biópsia endometrial na égua: importância no diagnóstico da subfertilidade e principais achados / Endometrial biopsy in the mare: importance in the diagnosis of subfertility and main findings

A biópsia endometrial na égua é uma técnica simples e bastante antiga. É uma importante ferramenta para o diagnóstico de patologia no endométrio nesta espécie utilizada para determinar o estágio do ciclo estral, para detectar a presença de inflamações agudas ou crônicas e para determina a possibilidade do útero levar a gestação a termo. Mais recentemente outras alterações tais como a má-diferenciação e as angiopatias, também estão sendo avaliadas em amostras de biópsia endometrial em éguas, uma vez que também podem interferir no prognóstico reprodutivo destas fêmeas. Esta revisão tem por objetivo descrever a avaliação da biópsia endometrial e as principais alterações que ocorrem no endométrio das éguas.(AU)

Endometrial biopsy in the mare is a simple and quite old technique. It is an important tool for the diagnosis of pathology in the endometrium in this species, used to determine the stage of the estrous cycle, to detect the presence of acute or chronic inflammation and to determine the possibility of the uterus carrying the pregnancy to term. More recently, other alterations, such as poor differentiation and angiopathies, are also being evaluated in endometrial biopsy samples in mares, since they may also interfere with the reproductive prognosis of these females. This review aims to describe the evaluation of the endometrial biopsy and the main changes that occur in the endometrium of mares.(AU)

Cetose subclínica e seu impacto no desempenho reprodutivo de vacas leiteiras: revisão de literatura / Subclinical ketosis and its impact on the reproductive performance of dairy cows: literature review

A cetose, conhecida também como acetonemia, é um distúrbio metabólico que afeta principalmente vacas leiteiras de alta produção. A elevação anormal de corpos cetônicos nos tecidos e fluidos corporais do animal ocorre devido a um déficit de energia. A quantidade de alimento/nutrientes ingeridos não é suficiente para suprir a demanda corporal do mesmo, assim como a eficiência reprodutiva que está diretamente ligada à saúde, condição corporal e sua capacidade de produção. Animais de alta produção possuem um desafio muito grande de aumentar a produção a cada lactação, com isso, estão susceptíveis a mudanças metabólicas, entre elas a cetose, clínica ou subclínica. Tal enfermidade ocorre devido a uma má adaptação metabólica do animal a sua nova condição de lactante. A elevada incidência de doenças uterinas no pós-parto de vacas leiteiras é responsável por inúmeros prejuízos para a atividade, principalmente pela redução da eficiência reprodutiva das vacas acometidas por infecções. Contudo, visto que a cetose subclínica prevalece nos rebanhos leiteiros de alta produção, o objetivo desta revisão de literatura é apresentar a patogenia e os efeitos que esse distúrbio metabólico têm sobre a reprodução das vacas de aptidão leiteira no após o parto, utilizando de indicadores como taxa de prenhez, taxa de concepção, retorno a ciclicidade, intervalo entre partos e intervalo entre parto e estro.(AU)

Ketosis, also known as acetonemia, is a metabolic disorder that primarily affects high-yielding dairy cows. The abnormal elevation of ketone bodies in the animal's tissues and body fluids occurs due to an energy deficit. The amount of food/nutrients ingested are not enough to supply the body's demand, as well as the reproductive efficiency that is directly linked to health, body condition and its production capacity. High production animals have a very big challenge to increase production with each lactation, therefore, they are susceptible to metabolic changes, including clinical or subclinical ketosis. Such a disease occurs due to a poor metabolic adaptation of the animal to its new lactating condition. The high incidence of uterine diseases in the postpartum period of dairy cows is responsible for numerous losses to the activity, mainly for the reduction of the reproductive efficiency of cows affected by infections. However, since subclinical ketosis prevails in high production dairy herds, the objective of this literature review is to present the pathogenesis and the effects that this metabolic disorder has on the reproduction of dairy cows in the postpartum period, using indicators such as pregnancy rate, conception rate, return to cyclicity, calving interval and calving-estrus interval.(AU)

Estratégias farmacológicas para a manipulação do ciclo estral de fêmeas bovinas de raças de corte taurinas / Pharmacological approaches to manipulate bovine estrous cycle in taurine beef breeds

Este texto discute as estratégias farmacológicas para a manipulação do ciclo estral de fêmeas taurinas de corte, com foco na inseminação artificial em tempo fixo (IATF). Os zebuínos, rebanho predominante no Brasil, apresentam características de ciclo estral diferentes das raças taurinas, o que justifica a busca por estratégias hormonais adaptadas para o controle do ciclo estral nas subespécies. O estradiol combinado com a progesterona (P4) e prostaglandina F2 alfa (PGF) é o esquema hormonal mais comumente utilizado para a manipulação do ciclo estral em protocolos de IATF. Porém, o uso de GnRH combinado ou em substituição aos ésteres de estradiol vem sendo considerado. Coletivamente, os dados do nosso grupo reforçam a necessidade de customizar as abordagens para o controle do ciclo estral de acordo com a composição genética das fêmeas bovinas.(AU)

This text discusses pharmacological strategies to manipulate the estrous cycle of taurine and synthetic females, with a focus on timed artificial insemination (TAI). Zebu cattle, the predominant herd in Brazil, have different estrous cycle characteristics than taurine breeds, requiring different synchronization hormonal strategies for each subspecies. Estradiol combined with progesterone (P4) and prostaglandin F2 alpha (PGF) is the most used hormonal scheme for estrous cycle manipulation in TAI protocols. But the use of GnRH instead of estradiol esters is being considered. Collectively, our group's data reinforce the need to customize approaches to estrous cycle control according to the genetic composition of bovine females.(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)

Sexual motivation and performance in sexual naïve and experienced rats treated with ivermectin: an ultrasonic vocalization study / Motivação e desempenho sexual em ratos com e sem experiência sexual tratados com ivermectina: um estudo da vocalização ultrassônica

In mammals, ivermectin acts as a GABAA receptor agonist and stimulates GABA release. Previous studies showed that ivermectin (IVM) reduces sexual performance, impairing the latency to the first mount and intromission. These parameters are usually considered motivational parameters of sexual behavior. However, IVM increases GABAergic activity leading to motor incoordination. Thus, it is reasonable to propose that IVM affects sexual performance via motor incoordination pathways. The present study analyzed ultrasonic vocalization in rats to verify whether IVM impairs sexual behavior via motivational mechanisms or motor impairment. Because sexual experience attenuates the impairment of motor performance, rats with sexual experience were also studied. Sexually naive and experienced rats were administered a therapeutic IVM dose and saline. The rats were exposed to receptive females, and the latency to the first mount was evaluated, followed by the 50-kHz USV test. IVM treatment in naïve rats increased the latency to first to mount relative to Saline naïve rats, while no differences were observed between saline and experienced rats. In naïve-IVM rats, a reduced frequency and total calls and increased mean time of calls occur relative to SAL-naïve rats. Experienced IVM rats did not show differences in the frequency, mean, and maximal calls close to Saline experienced rats. However, an increase in the total calls and the dominant frequency of calls were observed in IVM-experienced rats compared to Saline experienced rats. A negative and positive correlation occurred between the latency to the first mount and USVs in groups with and without ivermectin exposure. Hence, we propose that ivermectin increased the sexual motivation of rats exposed to a female in estrous based in USVs despite an increased latency to the first mount that occurred. The increased latency to the first mount resulted from motor incoordination, as previously observed and proposed by our group.(AU)

Em mamíferos, a ivermectina (IVM) atua como agonista do receptor GABAA e estimula a liberação de GABA. Estudos anteriores mostraram que a IVM reduz o desempenho sexual, prejudicando a latência para a primeira monta e intromissão. Esses parâmetros são geralmente considerados parâmetros motivacionais do comportamento sexual. Por outro lado, a IVM aumenta a atividade GABAérgica levando à incoordenação motora. Assim, é possível que a IVM afete o desempenho sexual devido a um impedimento motor. O presente estudo analisou a vocalização ultrassônica em ratos para verificar se a IVM prejudica o comportamento sexual via mecanismos motivacionais ou comprometimento motor. Uma vez que a experiência sexual atenua o comprometimento do desempenho motor, também foram estudados ratos com experiência sexual. Ratos sexualmente inexperientes e experientes foram administrados com uma dose terapêutica de IVM ou solução salina IVM. Os ratos foram expostos a fêmeas receptivas e foi avaliada a latência para a primeira monta, seguida do teste de vocalização ultrassônica (USV) de 50 kHz. O tratamento com IVM em ratos inexperientes aumentou a latência para a primeira monta em relação a ratos inexperientes tratados com solução salina, enquanto não foram observadas diferenças entre ratos experientes tratados com IVM e solução salina. Em ratos inexperientes tratados com IVM ocorreu redução da frequência e total de USVs, bem como aumento do tempo médio de USVs em relação aos ratos sem experiência. Ratos experientes tratados com IVM não mostraram diferenças na frequência, média e máxima das USVs em relação aos ratos experientes tratados com solução salina; no entanto, observou-se aumento no total de USVs e na frequência dominante de USVS em ratos experientes tratados com IVM comparados aos experientes tratados com solução salina. Observou-se correlação negativa e positiva entre a latência para a primeira monta e USVs nos grupos sem e com experiência tratados com IVM, respectivamente. Assim, propomos que a IVM aumentou a motivação sexual de ratos expostos a uma fêmea em estro com base em USVs, apesar de apresentar aumento na latência para a primeira monta. O aumento da latência para a primeira monta foi atribuída à incoordenação motora, conforme observado anteriormente e proposto por nosso grupo.(AU)

Effects of milking system in suckling period on growth, reproduction traits, and milk yield of East Friesian-cross dairy sheep

The main objective of this study was to determine the effects of milking system on growth, reproduction, and milk yield and composition of East Friesiancross (Tahirova) dairy sheep that were milked in the evening during the suckling period. A total of 43 Tahirova ewes and 58 lambs were used in the present study. One of the groups was milked in the evening (evening milked; EM) before coming together with their lambs, and the other group was not (not milked in the evening; NEM). Morning milking was performed in both groups during the study. Lambs in both groups were individually weaned at the age of 60 days. There was no statistical difference between the lambs' live weight at weaning in the EM and NEM groups, determined to be 23.46 and 24.11 kg, respectively. Live weight values of lambs were similar in the groups at ages of up to 180 days. The reproductive characteristics of ewe lambs in the EM and NEM groups, having similar growth rates and a similar live weight and body condition in the first estrus stages, were also similar. The return rate and frequency of return were close in both groups of ewe lambs. Milk yield of the NEM group was significantly higher than that of the EM group before and after weaning. However, in groups with similar lactation milk yield and length, the total marketable milk yield was higher in the suckling period of the EM group. The milking system in suckling period of Tahirova ewes does not significantly affect growth, average daily gain, and reproductive characteristics. Milk yield in the NEM group before and after weaning was significantly higher than the EM group, but the total marketable milk yield was higher in the EM group.(AU)

Correlation between estrus onset and ovarian parameters in dairy goats / Início do estro e sua correlação com os parâmetros ovarianos em cabras leiteiras

This study assessed the effects of social dominance on the behavioral estrus and ovarian parameters of dairy goats subjected to synchronous estrus induction during the non-breeding season. Synchronous estrus was induced in 23 dairy goats allocated to collective pens. Ovarian ultrasonography was performed at 12 h intervals from device removal to ovulation. Upon estrus onset (EO) detection, the goats were immediately removed from the pens. Dominance was scored according to EO in relation to device removal in each pen, with HD - high dominants (<36 h; n = 8), MD - medium dominants (36 to 48 h; n = 10) and LD - low dominants (>48 h; n = 5). Goats in estrus underwent flexible time artificial insemination (FxTAI) according to EO. The estrus response was 100.0%. The interval to estrus was longer (P<0.05) in LD (53.7 ± 6.5 h) than in MD (37.9 ± 5.5 h) and HD goats (32.3 ± 6.6 h), while the interval from device removal to ovulation was similar (P>0.05) among all groups. The interval from EO to FxTAI was longer in HD goats compared to the other groups (P<0.05). In conclusion, although social hierarchy influenced the time of EO, the ovarian parameters, including ovulation, were not affected.

Este estudo avaliou os efeitos da dominância social sobre o comportamento do estro e os parâmetros ovarianos de cabras leiteiras submetidas à indução sincronizada do estro durante a estação não reprodutiva. A sincronização foi induzida em 23 cabras leiteira alocadas em baias coletivas. A ultrassonografia foi realizada em intervalos de 12 horas desde a remoção do dispositivo até a ovulação. Após a detecção do início do estro (EO), as cabras foram imediatamente removidas dos currais. A dominância foi pontuada de acordo com EO em relação à remoção do dispositivo, sendo: HD - alto dominante (<36 h; n = 8), MD - médio dominante (36 a 48 h; n = 10) e LD - baixo dominante (>478 h; n = 5). As cabras em estro foram inseminadas artificialmente em tempo flexível (FxTAI). O intervalo de estro foi maior (P<0,05) em LD (53,7 ± 6,5 h) do que em MD (37,9 ± 5,5 h) e cabras HD (32,3 ± 6,6 h), por sua vez, o intervalo entre a remoção do dispositivo e a ovulação foi semelhante (P> 0,05) em todos os grupos. O intervalo de EO a FxTAI foi maior em cabras HD quando comparado aos outros grupos (P<0,05). Em conclusão, embora a hierarquia social tenha influenciado o tempo de início do estro, os parâmetros ovarianos incluindo a ovulação não foram afetados.

Clinical, sonographic and anatomopathological aspects of ovarian teratoma in a heifer / Aspectos clínicos, ultrassonográficos e anatomopatológicos do teratoma ovariano em uma novilha

Teratomas rarely occur in domestic species, especially in cattle. These tumors originate in fetal life and are characterized by rapid growth, which justifies their frequent detection in young animals. This study reported a case of ovarian teratoma in a heifer. On physical examination, the main signs identified were apathy, abdominal distention and tension, empty rumen, and mushy diarrhea. During rectal palpation, a mass was identified in the pelvic region, which was suggestive of cysts on ultrasound examination. The animal underwent laparotomy, followed by euthanasia due to a poor prognosis. At necropsy, a 54 x 43 x 52 cm (length x width x thickness) tumor was observed in the right ovary with multiple cystic areas, in addition to masses associated with multiple adhesions of the intestinal loops and peritonitis. On histopathology, muscle, cartilage, bone, nervous and epithelial tissue, glands, hair with follicles, were identified in the affected ovary. There was mixed inflammation and foci of necrosis observed with a complete absence of ovarian architecture in both the ovaries. Infiltrations were identified in the lymph nodes and mesenteric vessels. Glandular ducts were seen from the serosa to the intestinal mucosa. A locally infiltrative and expansile ovarian teratoma was diagnosed accordingly. It is considered that this kind of tumor can induce abdominal distension and absence of estrus in previously healthy, non-pregnant heifers.

Os teratomas são tumores raros nas espécies domésticas, sobretudo em bovinos. Esses tumores são caracterizados por crescimento rápido e origem durante a vida fetal, o que justifica seu diagnóstico frequente em animais jovens. O presente trabalho relata um caso de teratoma ovariano em uma novilha. No exame físico, os principais sinais identificados foram apatia, distensão e tensão abdominal, rúmen vazio e diarreia pastosa. Durante a palpação retal, uma massa foi identificada na região pélvica. Ao exame ultrassonográfico, a massa era sugestiva de cistos. O animal foi submetido a laparotomia, seguido de eutanásia devido ao mau prognóstico. Na necropsia foi observado um tumor de 54 x 43 x 52 cm (comprimento x largura x espessura) no ovário direito com múltiplas áreas císticas, além de massas associadas à múltiplas aderências das alças intestinais e peritonite. Na histopatologia foram identificados no ovário acometido a presença de tecidos muscular, cartilaginoso, ósseo, nervoso e epitelial, com glândulas, pelos e folículos. Havia inflamação mista e focos de necrose com ausência completa de arquitetura ovariana em ambos os ovários. Infiltrações foram identificadas em linfonodos e vasos mesentéricos. Ductos glandulares foram vistos desde a serosa até mucosa intestinal. Diagnosticou-se um teratoma ovariano localmente infiltrativo e expansivo. Considera-se que este tumor pode induzir distensão abdominal e ausência de estro em novilhas previamente sadias e não gestantes.

Conception rate according to sire, body condition score and estrus occurrence of suckled Bos taurus beef cows submitted to timed artificial insemination / Taxa de concepção de acordo com o touro, escore de condição corporal e ocorrência de estro em vacas de corte Bos taurus lactantes submetidas à inseminação artificial em tempo fixo

The objective of this study was to investigate the effect of estrus expression, body condition score (BCS), different sires and semen batches on the conception rate of suckled Bos taurus beef cows submitted to timed artificial insemination (TAI). Data from 7,737 TAI were obtained from five farms in South Brazil. Cows received an estradiol plus progesterone-based estrous synchronization protocol. Only sires (n = 13) with at least two semen batches and 50 AI in two different lots were included in the study. Conception rate was higher for cows in estrus (66.8% vs. 26.3%) or with BCS ≥ 3 (57.2% vs. 51.6%) than in cows without estrus or BCS < 3, respectively (P≤0.001). Conception rate per sire ranged from 42.6% (Sire L) to 74.3% (Sire K). Conception rate in cows with BCS ≥ 3 and estrus occurrence varied from 47.4% (Sire L) to 86.1% (Sire A) among sires. Conception rate differed among semen batches of the same sire (B1 = 58.5%, B2 = 62.5%, and B3 = 83.2%). In conclusion, there was individual variation in conception rate among AI sires and semen batches within sires. The conception rate was increased by estrus occurrence and greater BCS.

O objetivo deste estudo foi investigar o efeito da manifestação de estro, o escore de condição corporal (ECC), os diferentes touros e partidas de sêmen na taxa de concepção de vacas Bos taurus lactantes de corte submetidas à inseminação artificial em tempo fixo (IATF). Dados de 7.737 IATF foram obtidos em cinco fazendas do sul do Brasil. As vacas receberam um protocolo de sincronização de estro à base de estradiol e progesterona. Somente touros (n=13) com no mínimo duas partidas e 50 inseminações em dois lotes diferentes foram incluídos no estudo. A taxa de concepção foi maior nas vacas em estro (66,8% vs. 26,3%) ou com ECC ≥ 3 (57,2% vs. 51,6%) do que em vacas sem estro ou com menor ECC, respectivamente (P≤0,001). A taxa de concepção por touro variou de 42,6% (Touro L) a 74,3% (Touro K). A taxa de concepção em vacas que demonstraram estro e com ECC ≥3 variou de 47,4% (Touro L) a 86,1% (Touro A) entre os touros. A taxa de concepção diferiu entre partidas de um mesmo touro (B1=58,5%, B2=62,5% e B3=83,2%). Em conclusão, houve variação individual na taxa de concepção entre touros e entre as partidas de sêmen de um mesmo touro. A taxa de concepção foi aumentada pela ocorrência de estro e maior ECC.

Effect of ovarian status on reproductive performance in dairy heifers inseminated with sexed semen

Background: The intensive reproductive management in the dairy farms requires inclusion of a large group of replacement heifers in the breeding program for a shorter period. In this aspect, a creation of effective estrus synchronization protocols with timed artificial insemination (TAI) by sexed semen and optimization of the current ones have a crucial role for obtaining high pregnancy rate. These protocols are beneficial, because they led to reduced interval to first AI, lack of need for estrus detection, and allow obtaining a large group of female calves for on time. Because of limited fertilizing potential of sexed spermatozoa this type of semen is applied mainly for heifers, as fertility is higher compared to lactating cows. The main objective of the present study was to investigate the effect of ovarian status on the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Materials, Methods & Results: Forty-eight Holstein healthy heifers separated in 2 groups were subjected to PGF2α-GnRH pre-treatment and Ovsynch or PRID-5-day estrus synchronization protocol and timed artificial insemination (TAI) with sex-sorted semen, staring 6 days after end of the hormonal pre-treatment. The ovarian status (presence of follicles with or not a corpus luteum) of the heifers at the begin of the treatment, on day of TAI and pregnancy rate in different groups were determined and compared. Additionally, the ovarian status at the begin of the treatment, ovarian status and size of preovulatory follicle (PF) on day of TAI and total values for both groups according to reproductive performance (pregnant or non-pregnant) were also analyzed. On day of TAI the animals with PF and a lack of corpus luteum (CL) in both groups were more that those with PF and CL (39.3% and 30% vs. 60.7 % and 70%), with significant (P < 0.05) difference in PRID-5-day group. The pregnancy rate tended to be higher in PRID-5 day than Ovsynch treatment (65% vs. 35.7%). A higher percentage (100% and 67.9%) of the pregnant animals in both treatments had not CL on day of TAI, and the size of the PF (1.58 ± 0.12 cm and 1.64 ± 0.13 cm) was increased (P < 0.05). Similar effects of the ovarian status on reproductive performance were obtained after a comparison of the total values between pregnant and non-pregnant animals. The percentage of heifers with observed PF without CL on day of TAI was significantly greater (P < 0.05) in pregnant compared to non-pregnant group (91.3% vs. 40%). The opposite dependence was determined for the parameter presence of follicles and corpus luteum (8.7% vs. 60%; P < 0.05). Furthermore, the size of the PF measured immediately before TAI was increased in animals became pregnant (1.60 ± 0.12 cm vs. 1.34 ± 0.17 cm; P < 0.05). Discussion: The analysis of the obtained results showed that the ovarian status on day of TAI affects the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Hormonal pre-treatment with onset of PRID-5-day protocol 6 days later and TAI with sex-sorted semen ensure acceptable pregnancy rate. The greater preovulatory follicle and a lack of corpus luteum before insemination provide significantly (P < 0.05) more pregnant animals, compared to the cases when CL is presented. Ultrasound determination of the ovarian function before insemination can be used in selection of heifers for TAI with sex-sorted semen.

Vaginal cytology in mares in the different stages of the estral cycle associated with the seasons of the year / Citologia vaginal em éguas nas diferentes fases do ciclo estral associadas as estações do ano

The reproductive biotechnologies directly assist in the development of different methods of reproductive evaluation. The objective of this study was to develop a new method to determine the estrous cycle phase in equine females through vaginal cytology throughout the seasons, as well as to establish an estimate of inflammatory cells present in the vagina. Six mares were evaluated at different ages without a defined breed and reproductive activity and were subjected to ultrasound evaluation of the reproductive system and cytological analysis of the vaginal region. In the summer, there was a predominance of keratinized epithelial cells in the estrus and intermediate in the diestrus. In the autumn, there was a predominance of keratinized cells in estrus and parabasal cells in estrus and diestrus. In anestrus (winter), a greater number of parabasal cells was identified in relation to the other cell types. In estrus (spring), there was a predominance of parabasal and intermediate cells. Conversely, in diestrus, parabasals were found in greater numbers. The evaluation of inflammatory cells of the vaginal epithelium of mares showed greater activity in the summer; however, there are no reference values for healthy animals in the literature, and it is necessary to conduct studies on the subject. It is concluded that there is an influence of cyclicity on the vaginal epithelium of the equine species, varying according to the season. Additionally, vaginal cytological evaluation is an important complementary tool in the diagnosis of vaginitis in mares, requiring further research on the subject.(AU)

As biotecnologias reprodutivas auxiliam diretamente no desenvolvimento de diferentes métodos de avaliação repro-dutiva. O objetivo deste estudo foi desenvolver um novo método para determinar a fase do ciclo estral em fêmeas equinas através da citologia vaginal ao longo das estações, bem como estabelecer uma estimativa das células inflamatórias presentes na vagina. Seis éguas foram avaliadas em diferentes idades, sem raça definida e em atividade reprodutiva, e foram submetidas à avaliação ultrassonográfica do aparelho reprodutor e análise citológica da região vaginal. No verão, houve predomínio de células epiteliais queratinizadas no estro e intermediárias no diestro. No outono, houve predomínio de células queratinizadas no estro e células parabasais no estro e diestro. No anestro (inverno), foi identificado maior número de células parabasais em relação aos demais tipos celulares. No estro (primavera), houve predomínio de células parabasais e intermediárias. Por outro lado, no diestro, os parabasais foram encontrados em maior número. A avaliação das células inflamatórias do epitélio vaginal de éguas mostrou maior atividade no verão; entretanto, não há valores de referência para animais saudáveis na literatura, sendo necessário a rea-lização de estudos sobre o assunto. Conclui-se que há influência da ciclicidade no epitélio vaginal da espécie equina, variando de acordo com a estação do ano. Além disso, a avaliação citológica vaginal é uma importante ferramenta complementar no diagnóstico da vaginite em éguas, necessitando de mais pesquisas sobre o assunto.(AU)

In vitro sperm characteristics and in vivo fertility of sex-sorted and conventional semen in suckled Nelore cows at a traditional schedule for timed-AI with estrus detection / Características espermáticas in vitro e fertilidade in vivo de sêmen convencional e sexado em vacas Nelore pósparto submetidas à IATF tradicional com detecção de estro

The aim of this study was to assess in vitro sperm characteristics and pregnancies/AI (P/AI) of conventional and sex-sorted semen at timed-AI of suckled, multiparous Nelore cows. All cows (n=348) were submitted to a traditional estradiol/progesterone (P4)-based protocol. At 48h after P4-device removal, the estrous behavior was recorded, and AI was performed with conventional or sex-sorted semen from two bulls. The following sperm assessments were performed: CASA, Hyposmotic Test, sperm morphometry and chromatin structure by TB staining. P/AI were reduced (P<0.001) for sex-sorted compared to conventional semen in cows expressing estrus (27vs47%) or not (11vs.37%). Membrane integrity (Bull1: 30.3±9.6 vs. 52.3±12.4%, P=0.01; Bull2: 24.5±3.0 vs. 48.7±1.6%, P=0.006) and sperm concentration (Bulll: 23.2±0.6 vs. 43.0±0.8x10 sperm/mL, P<0.001; Bull2: 25.1+2.8 VS. 42.1±0.7x10 sperm/mL; P<0.001) were reduced in sex-sorted compared to conventional semen, for both bulls. Total and progressive motility were reduced in sex-sorted semen for Bull1 (TM: 49.7±15.9 vs. 94.9±1.9%, P=0.007; PM: 16.7±3.4 vs. 44.1±13.2%, P=0.009) and no differences were detected for Bull2 (TM: 45.0±17.5 vs. 68.2±19.1%, P=0.098; PM: 12.8±4.7 vs. 30.0±13.0%, P=0.065). Sperm ellipticity from sex-sorted was lower than conventional semen for Bull2 (0.306±0.01 vs. 0.342±0.02, P=0.02) and no difference was detected for Bull1 (0.332±0.01 vs. 0.330±0.01, P=0.55). Reduced in vivo fertility was observed for sex-sorted semen, regardless of estrous behavior. In vitro sperm quality of sex-sorted semen was compromised for both bulls, but differently affected for each sire.

O estudo teve como objetivo avaliar características espermáticas in vitro e a taxa de concepção (TC) de sêmen convencional e sexado em um programa de IATF tradicional de vacas Nelore pós-parto. Todas as vacas (n=348) foram submetidas ao mesmo protocolo de IATF à base de estradiol e de progesterona. Após 48 horas da retirada do implante, foi determinada a expressão de estro dos animais e a IA foi realizada com sêmen convencional e sexado de dois touros Angus. As seguintes características espermáticas foram avaliadas: análise computadorizada do sêmen, teste hiposmótico, morfometria espermática e estrutura cromatinica por meio da coloração com azul de toluidina. A TC foi menor (P<0,001) para sêmen sexado comparado ao convencional, em vacas que expressaram estro (27 vs. 47%) e que não apresentaram estro (11 vs. 37%). A integridade da membrana plasmática (Touro 1: 30,319,6 vs. 52,3+12,4%, P=0,010; Touro 2: 24,5+3,0 vs. 48,7±1,6%, P=0,006) e a concentração espermática (Touro 1: 23,2±0,6 vs. 43,0±0,8x10 sperm/mL, P<0,001; Touro 2: 25,1+2,8 vs. 42,1 +0,7x10'sperm/mL, P<0,001) foram menores no sêmen sexado comparado ao convencional, para ambos os touros. Motilidades total e progressiva foram menores no sêmen sexado comparado ao convencional para o Touro 1 (MT: 49,7±15,9 vs. 94,9±1,9%, P=0,007; MP: 16,7+3,4 vs. 44,1+13,2%, P=0,009), enquanto diferenças não foram detectadas no Touro 2 (MT: 45,0±17,5 vs. 68,2±19,1%, P=0,098; MP: 12,8±4,7 vs. 30,0±13,0%, P=0,065). Elipticidade espermática do sêmen sexado foi menor do que do sêmen convencional no Touro 2 (0,306±0,01 vs. 0,342±0,02, P=0,020), mas não houve diferença no Touro 1 (0,332±0,01 vs. 0,330±0,01, P=0,552). Reduzida fertilidade in vivo foi observada para o sêmen sexado em relação ao convencional, independentemente da expressão de cio das vacas. A qualidade seminal in vitro do sêmen sexado foi comprometida para ambos os touros, mas diferentemente afetada para cada reprodutor.

The ovarian and uterine responses of Baixadeiro mares to prostaglandin synchronization during the dry and rainy seasons

This study aimed to evaluate the effect of synchronization with prostaglandin F2α in Baixadeiro mares during the rainy and dry seasons. Fourteen mares were synchronized by administering two doses of 1 mL prostaglandin PGF 2α and monitored by rectal palpation and ultrasound for the assessment of follicular development and uterine echotexture. Of this total, nine mares allowed the collection of blood, in which the blood was collected by venipuncture of the jugular vein to determine progesterone (P4) by ELISA. Mares showed no differences (P > 0.05) in weight, body score condition (BSC), tone, uterine edema, frequency of ovulation, synchronization interval, estrus, and the total number of follicles between periods. However, there was a difference in large increased follicle diameter (P < 0.05) during the dry season. The average concentrations of P4 in mares differed (P < 0.05) between the pre- and post-ovulatory phases for both seasons and after ovulation, with higher concentrations in the rainy season. Furthermore, statistical differences in daily light (P < 0.05) were observed between the dry and rainy periods. Thus, we conclude that mares from the genetic grouping Baixadeiro showed no reproductive seasonality, though there was a difference in luminosity between the rainy and dry seasons. The treatment with two doses of PGF 2α was effective in synchronizing the mares, promoting the return of estrus in the dry and rainy periods. The mares remaining cyclically active throughout the year provided there were appropriate forage availability and quality levels to allow for normal values of body weight and condition.

The ovarian and uterine responses of Baixadeiro mares to prostaglandin synchronization during the dry and rainy seasons

This study aimed to evaluate the effect of synchronization with prostaglandin F2α in Baixadeiro mares during the rainy and dry seasons. Fourteen mares were synchronized by administering two doses of 1 mL prostaglandin PGF 2α and monitored by rectal palpation and ultrasound for the assessment of follicular development and uterine echotexture. Of this total, nine mares allowed the collection of blood, in which the blood was collected by venipuncture of the jugular vein to determine progesterone (P4) by ELISA. Mares showed no differences (P > 0.05) in weight, body score condition (BSC), tone, uterine edema, frequency of ovulation, synchronization interval, estrus, and the total number of follicles between periods. However, there was a difference in large increased follicle diameter (P < 0.05) during the dry season. The average concentrations of P4 in mares differed (P < 0.05) between the pre- and post-ovulatory phases for both seasons and after ovulation, with higher concentrations in the rainy season. Furthermore, statistical differences in daily light (P < 0.05) were observed between the dry and rainy periods. Thus, we conclude that mares from the genetic grouping Baixadeiro showed no reproductive seasonality, though there was a difference in luminosity between the rainy and dry seasons. The treatment with two doses of PGF 2α was effective in synchronizing the mares, promoting the return of estrus in the dry and rainy periods. The mares remaining cyclically active throughout the year provided there were appropriate forage availability and quality levels to allow for normal values of body weight and condition.(AU)