Use of threaded rigid cannula and flexible endoscope for single access video laparoscopy in standing horses

Com o objetivo de promover, por meio de acesso único e com o uso de endoscópio flexível, ampla exploração da cavidade peritoneal de equinos em estação, foi concebida uma cânula laparoscópica para dar sustentação ao endoscópio e possibilitar o acesso sob visualização. O procedimento foi realizado a partir da fossa paralombar. Após pequena incisão cutânea, o endoscópio foi inserido na cânula e os músculos e o peritônio foram divulsionados mediante rotação da cânula. Logo depois da perfuração do peritônio, foi realizada a exploração da cavidade e a identificação das estruturas. Em seguida à exploração do lado ipsilateral ao acesso, realizou-se a transposição do conjunto cânula/endoscópio ventralmente à porção caudal do cólon descendente, seguida de exploração do lado contralateral. Concluída a técnica, foi executado, para fins de comparação, o mesmo procedimento por meio da fossa paralombar contralateral. Foi possível a transposição do conjunto cânula/endoscópio para o lado contralateral ao acesso em todos os procedimentos. Também foi possível a identificação da maioria das estruturas abdominais tanto pelo acesso esquerdo quanto pelo direito. A abordagem por acesso único mostrou-se viável para a exploração ampla da cavidade peritoneal, demonstrando ser uma alternativa à técnica laparoscópica convencional.A laparoscopic cannula was designed to support a single access approach with a flexible endoscope for the wide exploration of the peritoneal cavity of standing horses. It provides support to the endoscope and allows access to the peritoneal cavity with a visual aid. This procedure was performed through the paralumbar fossa. After a small cutaneous incision, the endoscope was inserted into the cannula, and the muscles and peritoneum were divulsed through the rotation of the cannula. After the peritoneal perforation, cavity exploration and identification of structures were performed. After the exploration of the ipsilateral side of the access, the cannula/endoscope was transposed ventrally to the caudal portion of the descending colon; this was followed by the exploration of the contralateral side. Once this process was completed, the same procedure was performed through the contralateral paralumbar fossa for comparison. It was possible to transpose the cannula/endoscope set to the contralateral access side in all procedures. Further, it was possible to identify most of the abdominal structures in both the left and right access. This single access approach proved to be feasible for the extensive exploration of the peritoneal cavity, thereby indicating it can be an alternative to the conventional laparoscopic technique

Retrospective study of clinical cases in ruminants at the UFRGS veterinary teaching hospital

Background: The pillars of animal production are sanity, genetics and nutrition. Sanitary control of the herd is important to reduce production costs and maintain health. The Veterinary Clinics Hospital (HCV) of the Federal University of Rio Grande do Sul (UFRGS), located in Porto Alegre - RS, is the place of greatest casuistry of the state, with 20.000 annual attendances, between small and large animals. In view of this scenario, the present study aimed to determine the frequency and characterize the ruminants attended at HCV, in order to help in the future, in the construction of control and prevention strategies of diseases found. Materials, Methods & Results: The documents of ruminant care between January 2007 and May 2018 were searched in the archives of the Hospital of Veterinary Clinics of UFRGS. Data on species, race, sex, age and diagnosis were collected. Diagnoses were classified as conclusive and inconclusive and the cases with conclusive diagnosis were classified according to etiology: infectious and parasitic diseases, metabolic and nutritional diseases, reproductive and obstetric diseases, toxic diseases, traumatic diseases. The prevalence of diseases and characteristics of ruminants attended (species, sex, category) was calculated. During the study period, between January 2007 and May 2018, 341 ruminants were attended, with emphasis on sheep (42%), goats (39%) and cattle (18%). In addition, a camel with foreign body obstruction, a sambar deer with fracture of the first thoracic vertebra and a buffalo with ruminal impaction were attended. The care profile was mapped, with predominance of females (57%) and adults (59%). Most of the animals did not present a defined breed, but among the breeds stands out Texel, of cutting aptitude, in sheeps and Saanen and Holstein, of dairy aptitude, in goats and cattle, respectively. In the retrospective study, the diseases with infectious and parasitic etiology presented the highest prevalence with 27.5% of the attendances, followed by reproductive (17.5%), traumatic (13.5%), metabolic (10%), others (10%) and toxic (2.5%). Sixty-six animals had inconclusive diagnosis (19.5%). Discussion: The highest prevalences were infectious and parasitic diseases, with emphasis on myiasis and verminosis. So, it is perceived that management corrections are sufficient to reduce the number of occurrences of diseases and prophylactic measures such as vaccination protocol, vermifugation and adequate nutritional management are allied in this walk. Among the reproductive diseases, dystocia (42.85%), which is one of the main causes of mortality in the peripartum period, has been highlighted. Dog attack was the major cause of traumas in ruminants and urolithiasis was highlighted in metabolic diseases. In toxic diseases, copper intoxication was the most important. Sheep are extremely sensitive to this intoxication, as they tend to accumulate copper in the organism. The retrospective study made it possible to visualize the panorama of HCV UFRGS visits to ruminants in the last years, mapping the profile and determining the casuistry of the diseases. Studies of hospital veterinary casuistry are rare, mainly involving ruminants. At the end, it is concluded that studies referring to casuistry are important to know the predominant diseases in a specific area and its risk factors considering differential diagnosis and future prevention programs

Retrospective Study of Clinical Cases in Ruminants at the UFRGS Veterinary Teaching Hospital

Background: The pillars of animal production are sanity, genetics and nutrition. Sanitary control of the herd is important to reduce production costs and maintain health. The Veterinary Clinics Hospital (HCV) of the Federal University of Rio Grande do Sul (UFRGS), located in Porto Alegre - RS, is the place of greatest casuistry of the state, with 20.000 annual attendances, between small and large animals. In view of this scenario, the present study aimed to determine the frequency and characterize the ruminants attended at HCV, in order to help in the future, in the construction of control and prevention strategies of diseases found. Materials, Methods & Results: The documents of ruminant care between January 2007 and May 2018 were searched in the archives of the Hospital of Veterinary Clinics of UFRGS. Data on species, race, sex, age and diagnosis were collected. Diagnoses were classified as conclusive and inconclusive and the cases with conclusive diagnosis were classified according to etiology: infectious and parasitic diseases, metabolic and nutritional diseases, reproductive and obstetric diseases, toxic diseases, traumatic diseases. The prevalence of diseases and characteristics of ruminants attended (species, sex, category) was calculated. During the study period, between January 2007 and May 2018, 341 ruminants were attended, with emphasis on sheep (42%), goats (39%) and cattle (18%). In addition, a camel with foreign body obstruction, a sambar deer with fracture of the first thoracic vertebra and a buffalo with ruminal impaction were attended. The care profile was mapped, with predominance of females (57%) and adults (59%). Most of the animals did not present a defined breed, but among the breeds stands out Texel, of cutting aptitude, in sheeps and Saanen and Holstein, of dairy aptitude, in goats and cattle, respectively. In the retrospective study, the diseases with infectious and parasitic etiology presented the highest prevalence with 27.5% of the attendances, followed by reproductive (17.5%), traumatic (13.5%), metabolic (10%), others (10%) and toxic (2.5%). Sixty-six animals had inconclusive diagnosis (19.5%). Discussion: The highest prevalences were infectious and parasitic diseases, with emphasis on myiasis and verminosis. So, it is perceived that management corrections are sufficient to reduce the number of occurrences of diseases and prophylactic measures such as vaccination protocol, vermifugation and adequate nutritional management are allied in this walk. Among the reproductive diseases, dystocia (42.85%), which is one of the main causes of mortality in the peripartum period, has been highlighted. Dog attack was the major cause of traumas in ruminants and urolithiasis was highlighted in metabolic diseases. In toxic diseases, copper intoxication was the most important. Sheep are extremely sensitive to this intoxication, as they tend to accumulate copper in the organism. The retrospective study made it possible to visualize the panorama of HCV UFRGS visits to ruminants in the last years, mapping the profile and determining the casuistry of the diseases. Studies of hospital veterinary casuistry are rare, mainly involving ruminants. At the end, it is concluded that studies referring to casuistry are important to know the predominant diseases in a specific area and its risk factors considering differential diagnosis and future prevention programs

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Flexible videolaparoscopy by single access via paralumbar fossa using long threaded visual cannula in the abdominal exploration of standing horses

A laparoscopia é técnica cirúrgica minimamente invasiva na qual se utiliza um laparoscópio inserido por via transabdominal por onde é possível inspecionar visualmente a superfície das vísceras e do peritônio e realizar procedimentos cirúrgicos. Até o momento, a laparoscopia diagnóstica em equinos em estação através da fossa paralombar exige que sejam realizados dois procedimentos (um de cada lado do animal) para visualização significativa da cavidade peritoneal, além do uso de laparoscópio específico. Com o intuito de desenvolver a laparoscopia diagnóstica em equinos em estação por acesso único, foi desenvolvida uma cânula óptica com espiral sem trocarte de 60 cm de comprimento que tem o objetivo de promover maior segurança ao acesso laparoscópico (penetração radial sem trocarte e sob visualização) e sustentação ao endoscópio flexível para que seja possível realizar exploração significativa de ambos os hemisférios abdominais dorsais por apenas uma das fossas paralombares. Foram utilizados seis equinos adultos, sendo três machos e três fêmeas, submetidos a jejum alimentar de 24 a 30 horas. Amostras de sangue para realização de hemograma e dosagem de fibrinogênio foram obtidas no D-Pré, D4 e D7. Os equinos foram sedados com cloridrato de detomidina, seguido de bloqueio anestésico local com cloridrato de lidocaína infundida na musculatura e tecido subcutâneo do local de incisão no centro da fossa paralombar. O procedimento cirúrgico teve início com incisão cutânea de cerca de 2 cm de comprimento. As camadas musculares da região foram afastadas através da rotação da cânula em sentido horário e o afastamento dos tecidos foi acompanhado pelas imagens produzidas pelo endoscópio flexível e reproduzidas no monitor. Logo da perfuração do peritônio, foi iniciada a exploração da cavidade. Após a exploração do lado ipsilateral ao local de acesso, foi realizada a transposição do conjunto cânula/endoscópio ventralmente à porção caudal do cólon descendente seguida de exploração do lado contralateral. Terminado o exame, o conjunto foi removido através da rotação da cânula no sentido anti-horário e a incisão de pele foi suturada junto ao subcutâneo. A movimentação da cânula entre os órgãos abdominais mostrou-se segura, no entanto, em dois animais houve lesão iatrogênica ao baço, evidenciada por discreta hemorragia local. Foi possível a identificação da maioria das estruturas abdominais descritas na literatura por procedimento laparoscópico em equinos em estação pelo acesso único. Em cinco dos seis animais houve formação de enfisema subcutâneo adjacente às feridas cirúrgicas. Os parâmetros hematológicos dos animais mantiveram-se dentro dos limites estabelecidos para a espécie, com exceção dos leucócitos totais, neutrófilos segmentados e fibrinogênio que demonstraram pequenas variações. A abordagem proposta mostrou-se viável e tem o potencial de tornar o procedimento mais rápido, prático e seguro e menos invasivo e oneroso, fomentando a aplicação da laparoscopia diagnóstica na espécie equina.Laparoscopy is a minimally invasive surgical technique by using a laparoscope inserted through the abdominal wall where it is visually possible to inspect visceral surfaces and peritoneum, and to perform surgical procedures. Up to now, diagnostic laparoscopy in standing horses through the paralumbar fossa requires two procedures to be performed (one on each side of the animal) in order to significantly see the peritoneal cavity, in addition of using specific laparoscope. With the purpose to develop a diagnostic laparoscopy in standing horses through a single access, a trocarless threaded visual cannula 60 cm length was designed with the aim to promote higher safety to laparoscopic access (radial penetration without trocar and under visualization), and support to a flexible endoscope so that a significant exploration of both dorsal abdominal hemispheres through only one of the paralumbar fossa is possible to perform. Six mature horses were used: three males and three females. Food was withheld for 24 to 30 hours before surgery. Blood samples to perform complete blood count and fibrinogen metering were obtained in D-Pre, D4, and D7. The horses were sedated with detomidine hydrochloride, followed by local anesthesia blockade with lidocaine hydrochloride infused in the muscle and subcutaneous tissue at the incision place in the center of the paralumbar fossa. The surgical procedure started with a skin incision of nearly 2 cm length. Muscle layers of the region were moved away through clockwise cannula rotation and the distancing of the tissues were followed by images produced by the flexible endoscope and played on the monitor. After the peritoneum perforation, the cavity exploration was started. After the ipsilateral side exploration to the access site, the transposing of the set cannula/endoscope was performed ventrally to the rear portion of the descending colon followed by the contralateral side exploration. When the examination was finished, the set was removed through counterclockwise cannula rotation and the skin incision was stitched to the subcutaneous. Moving the cannula among the abdominal organs was shown to be safe; however, spleen iatrogenic injury in two animals was highlighted by minor local hemorrhage. The majority of the abdominal structures described in the literature was possible to identify through the laparoscopic procedure in standing horses by single access. There was subcutaneous emphysema formation adjoining the surgical wounds in five of the six animals. The hematological parameters of the animals were kept in the limits established for the species, with exception of total leucocytes, segmented neutrophils and fibrinogen which showed small variations. The proposed approach was shown to be feasible and has the potential to make the procedure faster, more practical and safe and less invasive and expensive, fostering the diagnostic laparoscopy application in the equine species

Ovarian follicular dynamics in beef cows treated with three protocols of synchronization of ovulation

Este trabalho teve por objetivo avaliar a dinâmica folicular de vacas de corte tratadas com protocolos para a sincronização da ovulação onde se utilizou implantes vaginais impregnados com progesterona ou com acetato de medroxi-progesterona e um implante auricular impregnado com norgestomet, além da utilização de ésteres de estradiol em diferentes doses. Foram utilizadas nove vacas Braford, multíparas, não-lactantes, cíclicas e com CC>=3. Os animais foram mantidos confinados e alimentados com feno e ração. Os animais foram divididos em três tratamentos, sendo que todos os animais passaram pelos três tratamentos em quatro repetições. Em cada repetição os animais foram divididos entre os três grupos de forma homogênea. No grupo 1 (n = 14), os animais receberam no dia 0, uma esponja vaginal impregnada com 250 mg de acetato de medroxi-progesterona (MAP) e uma aplicação intramuscular (i.m.) de 2 mg de benzoato de estradiol (BE); no dia 8, a esponja vaginal foi retirada e aplicado i.m. 0,5 mg de Cloprostenol e 24 horas após foi aplicado i.m. 1 mg de BE. No grupo 2 (n = 7), os animais receberam no dia 0, um implante vaginal de silicone impregnado com 1 g de progesterona e uma aplicação i.m. de 2 mg de BE; no dia 8, o implante foi retirado e aplicado i.m. 0,5 mg de Cloprostenol e 24 horas após foi aplicado i.m. 1 mg de BE. No grupo 3 (n = 8), os animais receberam no dia 0, um implante auricular de silicone impregnado com 3 mg de Norgestomet e uma aplicação i.m. de 3 mg de Norgestomet e 5 mg de Valerato de Estradiol (VE); no dia 9 o implante auricular foi retirado. Os animais foram examinados diariamente por via trans-retal com um ultra-som equipado com um transdutor linear de 8 MHz para monitorar a dinâmica folicular e luteal nos ovários. Após a retirada do implante auricular no grupo 3 e após a aplicação de 1 mg de BE nos grupos 1 e 2, os animais foram avaliados por ultra-sonografia duas vezes por dia até que a ovulação fosse detectada. No grupo 1, sete animais perderam a esponja vaginal impregnada com MAP e os dados foram retirados das análises. Os três tratamentos foram eficientes em promover uma nova onda de crescimento folicular sincronizada em 3,7 ± 1,1, 3,7 ± 0,7 e 4,9 ± 1,1 dias (P = 0,059) nos grupos 1, 2 e 3, respectivamente. Além de promover a ovulação de um folículo dominante com poucos dias de dominância e com diâmetro satisfatório em 66 ± 12, 66 ± 0 e 70,5 ± 12,7 horas após a retirada do implante (P = 0,62) nos grupos 1, 2 e 3, respectivamente. Portanto, os três protocolos foram eficientes em promover a sincronização da ovulação e são indicados para utilização em programas de inseminação artificial a tempo fixo em vacas de corte.This experiment was done to evaluate the ovarian follicular dynamics in beef cows treated with protocols of synchronization of ovulation where were used vaginal implants impregnated with progesterone or with medroxi-progesterone acetate and an ear implant impregnated with norgestomet, than the use of estradiol esters in different doses. Nine Braford cows, multiparous non-lactating, cyclic and BCS>=3 where used in these trial. The animals were kept confined and fed with hay and concentrated. The animals were divided into three treatments, which all animals went for three treatments in four replicates. In each replicate the animals were divided among groups homogeneously. Group 1 (n = 14), animals received on day 0, a vaginal sponge impregnated with 250 mg medroxi-progesterone acetate (MPA) and an intramuscular (i.m.) application of 2 mg of estradiol benzoate (EB); on day 8, the vaginal sponge was removed and applied i.m. 0.5 mg cloprostenol and 24 hours latter was applied i.m. 1 mg of EB. Group 2 (n = 7), the animals received on day 0, a silicone vaginal implant with 1 g of progesterone and an application i.m. of 2 mg of EB; on day 8, the implant was removed and applied i.m. 0.5 mg cloprostenol and 24 hours latter was applied i.m. 1 mg of EB. Group 3 (n = 8), the animals received on day 0, a silicone ear implant impregnated with 3 mg norgestomet and an application i.m. of 3 mg norgestomet and 5 mg of estradiol valerate; on the 9th day the implant was removed. From day 0, animals were examined daily by trans-rectal ultrasound with an 8 MHz linear transducer to monitor follicular and luteal dynamics. After removal of the implant in group 3 and after application of 1 mg EB in the other groups, the animals were evaluated by ultrasound two times per day until ovulation was detected. In group 1, seven animals lost a vaginal sponge impregnated with MPA and the data were removed from analysis. The three treatments groups were effective in promoting a new follicular wave emergence synchronously in 3,7 ± 1,1, 3,7 ± 0,7 and 4,9 ± 1,1 days (P = 0,059) in the groups 1, 2 and 3, respectively. Besides promoting ovulation a dominant follicle with few days of dominance and with satisfactory diameter in 66 ± 12, 66 ± 0 and 70,5 ± 12,7 hours after implant removal (P = 0,62) in the groups 1, 2 and 3, respectively. Therefore, the three protocols were effective in promoting the synchronization of ovulation and are indicated for use in fixed-time artificial insemination programs in beef cows

Ovarian follicular dynamics in beef cows treated with three protocols of synchronization of ovulation

Este trabalho teve por objetivo avaliar a dinâmica folicular de vacas de corte tratadas com protocolos para a sincronização da ovulação onde se utilizou implantes vaginais impregnados com progesterona ou com acetato de medroxi-progesterona e um implante auricular impregnado com norgestomet, além da utilização de ésteres de estradiol em diferentes doses. Foram utilizadas nove vacas Braford, multíparas, não-lactantes, cíclicas e com CC>=3. Os animais foram mantidos confinados e alimentados com feno e ração. Os animais foram divididos em três tratamentos, sendo que todos os animais passaram pelos três tratamentos em quatro repetições. Em cada repetição os animais foram divididos entre os três grupos de forma homogênea. No grupo 1 (n = 14), os animais receberam no dia 0, uma esponja vaginal impregnada com 250 mg de acetato de medroxi-progesterona (MAP) e uma aplicação intramuscular (i.m.) de 2 mg de benzoato de estradiol (BE); no dia 8, a esponja vaginal foi retirada e aplicado i.m. 0,5 mg de Cloprostenol e 24 horas após foi aplicado i.m. 1 mg de BE. No grupo 2 (n = 7), os animais receberam no dia 0, um implante vaginal de silicone impregnado com 1 g de progesterona e uma aplicação i.m. de 2 mg de BE; no dia 8, o implante foi retirado e aplicado i.m. 0,5 mg de Cloprostenol e 24 horas após foi aplicado i.m. 1 mg de BE. No grupo 3 (n = 8), os animais receberam no dia 0, um implante auricular de silicone impregnado com 3 mg de Norgestomet e uma aplicação i.m. de 3 mg de Norgestomet e 5 mg de Valerato de Estradiol (VE); no dia 9 o implante auricular foi retirado. Os animais foram examinados diariamente por via trans-retal com um ultra-som equipado com um transdutor linear de 8 MHz para monitorar a dinâmica folicular e luteal nos ovários. Após a retirada do implante auricular no grupo 3 e após a aplicação de 1 mg de BE nos grupos 1 e 2, os animais foram avaliados por ultra-sonografia duas vezes por dia até que a ovulação fosse detectada. No grupo 1, sete animais perderam a esponja vaginal impregnada com MAP e os dados foram retirados das análises. Os três tratamentos foram eficientes em promover uma nova onda de crescimento folicular sincronizada em 3,7 ± 1,1, 3,7 ± 0,7 e 4,9 ± 1,1 dias (P = 0,059) nos grupos 1, 2 e 3, respectivamente. Além de promover a ovulação de um folículo dominante com poucos dias de dominância e com diâmetro satisfatório em 66 ± 12, 66 ± 0 e 70,5 ± 12,7 horas após a retirada do implante (P = 0,62) nos grupos 1, 2 e 3, respectivamente. Portanto, os três protocolos foram eficientes em promover a sincronização da ovulação e são indicados para utilização em programas de inseminação artificial a tempo fixo em vacas de corte.This experiment was done to evaluate the ovarian follicular dynamics in beef cows treated with protocols of synchronization of ovulation where were used vaginal implants impregnated with progesterone or with medroxi-progesterone acetate and an ear implant impregnated with norgestomet, than the use of estradiol esters in different doses. Nine Braford cows, multiparous non-lactating, cyclic and BCS>=3 where used in these trial. The animals were kept confined and fed with hay and concentrated. The animals were divided into three treatments, which all animals went for three treatments in four replicates. In each replicate the animals were divided among groups homogeneously. Group 1 (n = 14), animals received on day 0, a vaginal sponge impregnated with 250 mg medroxi-progesterone acetate (MPA) and an intramuscular (i.m.) application of 2 mg of estradiol benzoate (EB); on day 8, the vaginal sponge was removed and applied i.m. 0.5 mg cloprostenol and 24 hours latter was applied i.m. 1 mg of EB. Group 2 (n = 7), the animals received on day 0, a silicone vaginal implant with 1 g of progesterone and an application i.m. of 2 mg of EB; on day 8, the implant was removed and applied i.m. 0.5 mg cloprostenol and 24 hours latter was applied i.m. 1 mg of EB. Group 3 (n = 8), the animals received on day 0, a silicone ear implant impregnated with 3 mg norgestomet and an application i.m. of 3 mg norgestomet and 5 mg of estradiol valerate; on the 9th day the implant was removed. From day 0, animals were examined daily by trans-rectal ultrasound with an 8 MHz linear transducer to monitor follicular and luteal dynamics. After removal of the implant in group 3 and after application of 1 mg EB in the other groups, the animals were evaluated by ultrasound two times per day until ovulation was detected. In group 1, seven animals lost a vaginal sponge impregnated with MPA and the data were removed from analysis. The three treatments groups were effective in promoting a new follicular wave emergence synchronously in 3,7 ± 1,1, 3,7 ± 0,7 and 4,9 ± 1,1 days (P = 0,059) in the groups 1, 2 and 3, respectively. Besides promoting ovulation a dominant follicle with few days of dominance and with satisfactory diameter in 66 ± 12, 66 ± 0 and 70,5 ± 12,7 hours after implant removal (P = 0,62) in the groups 1, 2 and 3, respectively. Therefore, the three protocols were effective in promoting the synchronization of ovulation and are indicated for use in fixed-time artificial insemination programs in beef cows