RESUMO

This study aimed to evaluate the to evaluate the occurrence rate of bovine brucellosis and tuberculosis in dairy herds of Acre State, Brazil. The survey was performed on 487 lactating cows distributed across 27 farms in seven cities from June 2018 to February 2019. Farms were selected according to the following criteria: volume of milk production (150 L/day), distance to an urban perimeter (43 km), and time of dairy activity (12 years). For the diagnosis of brucellosis, buffered acidified plate antigen (BAPA) and complement fixation (CF) tests were used. Among the investigated animals, the occurrence rates for brucellosis and tuberculosis were 1.88% (9/487) and 1.23% (6/487), respectively; among the investigated farms, 11.11% (3/27) and 22.2% (6/27) had livestock diagnosed as positive for brucellosis and tuberculosis, respectively. The farms with tuberculosis-positive cattle possessed some common features with respect to herd size. These farms had considerable herd sizes, which were reared extensively in pastures shared with other susceptible or pathogen-carrying animals. In conclusion, the occurrence rate of bovine brucellosis and tuberculosis in dairy herds from Acre state is, in general, lower than that observed in other states of Brazil. Nevertheless, there is an urgent need for developing strategies to control and eradicate both diseases to prevent eventual outbreaks and pathogen dissemination.(AU)

Este estudo teve como objetivo avaliar a taxa de ocorrência de brucelose e tuberculose bovina em rebanhos leitei-ros do Estado do Acre, Brasil. A pesquisa foi realizada em 487 vacas em lactação distribuídas em 27 fazendas em sete cidades de junho de 2018 a fevereiro de 2019. As fazendas foram selecionadas de acordo com os seguintes critérios: volume de produ-ção de leite (150 L / dia), distância do perímetro urbano (43 km), e tempo de atividade leiteira (12 anos). Para o diagnóstico da brucelose, foram utilizados os testes de antígeno acidificado tamponado (AAT) e de fixação de complemento (FC). Entre os animais investigados, as taxas de ocorrência de brucelose e tuberculose foram de 1,88% (9/487) e 1,23% (6/487), respec-tivamente; entre as propriedades investigadas, 11,11% (3/27) e 22,2% (6/27) tiveram rebanhos diagnosticados como positi-vos para brucelose e tuberculose, respectivamente. As propriedades com rebanho positivo para tuberculose possuíam algumas características comuns com relação ao tamanho do rebanho. Essas fazendas tinham rebanhos consideráveis, que eram criados extensivamente em pastagens compartilhadas com outros animais suscetíveis ou portadores de patógenos. Em conclusão, a taxa de ocorrência de brucelose e tuberculose bovina em rebanhos leiteiros do estado do Acre é, em geral, inferior à observada em outros estados do Brasil. No entanto, há uma necessidade urgente de desenvolver estratégias para controlar e erradicar ambas as enfermidades, para prevenir eventuais surtos e disseminação de patógenos.(AU)

Assuntos

RESUMO

This study aimed to evaluate the to evaluate the occurrence rate of bovine brucellosis and tuberculosis in dairy herds of Acre State, Brazil. The survey was performed on 487 lactating cows distributed across 27 farms in seven cities from June 2018 to February 2019. Farms were selected according to the following criteria: volume of milk production (150 L/day), distance to an urban perimeter (43 km), and time of dairy activity (12 years). For the diagnosis of brucellosis, buffered acidified plate antigen (BAPA) and complement fixation (CF) tests were used. Among the investigated animals, the occurrence rates for brucellosis and tuberculosis were 1.88% (9/487) and 1.23% (6/487), respectively; among the investigated farms, 11.11% (3/27) and 22.2% (6/27) had livestock diagnosed as positive for brucellosis and tuberculosis, respectively. The farms with tuberculosis-positive cattle possessed some common features with respect to herd size. These farms had considerable herd sizes, which were reared extensively in pastures shared with other susceptible or pathogen-carrying animals. In conclusion, the occurrence rate of bovine brucellosis and tuberculosis in dairy herds from Acre state is, in general, lower than that observed in other states of Brazil. Nevertheless, there is an urgent need for developing strategies to control and eradicate both diseases to prevent eventual outbreaks and pathogen dissemination.

Este estudo teve como objetivo avaliar a taxa de ocorrência de brucelose e tuberculose bovina em rebanhos leitei-ros do Estado do Acre, Brasil. A pesquisa foi realizada em 487 vacas em lactação distribuídas em 27 fazendas em sete cidades de junho de 2018 a fevereiro de 2019. As fazendas foram selecionadas de acordo com os seguintes critérios: volume de produ-ção de leite (150 L / dia), distância do perímetro urbano (43 km), e tempo de atividade leiteira (12 anos). Para o diagnóstico da brucelose, foram utilizados os testes de antígeno acidificado tamponado (AAT) e de fixação de complemento (FC). Entre os animais investigados, as taxas de ocorrência de brucelose e tuberculose foram de 1,88% (9/487) e 1,23% (6/487), respec-tivamente; entre as propriedades investigadas, 11,11% (3/27) e 22,2% (6/27) tiveram rebanhos diagnosticados como positi-vos para brucelose e tuberculose, respectivamente. As propriedades com rebanho positivo para tuberculose possuíam algumas características comuns com relação ao tamanho do rebanho. Essas fazendas tinham rebanhos consideráveis, que eram criados extensivamente em pastagens compartilhadas com outros animais suscetíveis ou portadores de patógenos. Em conclusão, a taxa de ocorrência de brucelose e tuberculose bovina em rebanhos leiteiros do estado do Acre é, em geral, inferior à observada em outros estados do Brasil. No entanto, há uma necessidade urgente de desenvolver estratégias para controlar e erradicar ambas as enfermidades, para prevenir eventuais surtos e disseminação de patógenos.

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RESUMO

Progesterone (P4) is essential for embryonic development and maintenance of pregnancy when deficiency causes early embryonic loss. In this study, we investigated the ability of hormonal supplementation to improve the fertility of Nellore females subjected to fixed-time artificial insemination (IATF) protocols. Here, we evaluated the effect of long-acting injectable progesterone (iP4) supplementation in the D4 after IATF on pregnancy rate and pregnancy loss in Nellore females (Bos taurus indicus) from different reproductive categories in Western Amazonia. Eight hundred thirteen Nellore females from 5 farms were selected and distributed into 2 groups: control [GC; administration of 0.5 mL of 0.9% saline solution, intramuscularly - IM] (n = 407) and a group that received injectable progesterone (iP4) that was long-acting [GiP4; administration of 0.5 mL of iP4, 300 mg, via IM four days after IATF] (n = 406). Each group contained 3 subgroups: heifers, primiparous cows, and multiparous cows. Of the 407 animals in the CG, 103 were heifers, 107 primiparous, and 197 multiparous. Of the 406 animals in the GiP4 group, there were 101 heifers, 107 primiparous, and 198 multiparous. On a random day of the estrous cycle (D0), an intravaginal device containing 1 g of P4 and 2 mg of estradiol benzoate (BE) was inserted by intramuscular injection. On D8, the P4 device was removed and 150 µg of D-cloprostenol (PGF2α), 300 IU eCG, and 1 mg BE were administered IM. Cows were inseminated at D10, 48-52 h after procedure on D8. Pregnancy diagnosis was made between 35 and 40 days after insemination through ultrasound examination. Between 80 and 90 days after insemination, a new ultrasound examination was performed to assess early pregnancy loss. The data were processed using the SAS 9.2. The conception rate, pregnancy loss, and final conception rate were analyzed using PROC GLIMMIX according to groups (CG and GiP4), categories (heifers, primiparous and multiparous), and their interactions as variables. The differences in the means of least squares were adjusted using the Tukey­Kramer method. Statistical significance was defined as P < 0.05. The general conception rate was 46% (375/816). Regardless of the animal class, GiP4 animals (51.97%) had higher conception rates (P < 0.05) than CG (40.29%). In the subgroups (heifers, primiparous and multiparous cows), there was a difference (P < 0.05) between animals treated with iP4 (52.48%, 57.94%, and 48.48%, respectively) and those who were not (39.81%, 41.12%, and 40.10%, respectively). Gestational losses, regardless of the animal class, were higher in females in the CG (7.93%) [P < 0.05] compared to those in the GiP4 group (2.84%). Regardless of treatment with iP4, the percentage of gestational loss in heifers was significantly higher (10.64%) than that in primiparous and multiparous cows (3.77% and 2.86%, respectively). The final conception rates were higher in animals that received long-acting iP4, which increased the final pregnancy in all parity categories. In the present study, the use of iP4 increased the pregnancy rate in Nellore females, regardless of the category. Although there has been no consensus on the use of iP4, there is an agreement that increases in the pregnancy rate are related to the moment of exogenous P4 application. In addition to influencing the pregnancy rate, reduction in pregnancy losses is also attributed to iP4 treatment, a fact demonstrated in the present study, where animals treated with iP4 had a lower pregnancy loss rate than normally occurs in beef cattle. Supplementation with long-acting iP4 increased the pregnancy rate at D35-40, reduced pregnancy losses, and increased the conception rate on D80-90 days in Nellore females reared in the Western Amazon, regardless of the animal category.(AU)

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This study aimed to evaluate the effect of sodium caseinate added into freezing extender on the sperm parameters of cryopreserved bull semen and in vitro and in vivo fertility. One ejaculate of 30 bulls was used and processed using Botu-Bov (Botupharma, Botucatu, Brazil) with the addition of 20% egg yolk (EY) or 15% egg yolk with 2% sodium caseinate (EY + SC), subsequently submitted to freezing. Semen from both groups were evaluated immediately after thawing (T0) and after thermic stress at 37 °C for 90 min (T90), for sperm kinetics, by CASA method, and plasma membrane integrity (PMI), superoxide (O2-) concentration and high mitochondrial potential (HMP) by flow cytometry. In vitro fertilization (IVF) was performed to assess embryo cleavage rate on day 3, and blastocyst rate on day 8. The in vivo fertility test was performed using fixed-time artificial insemination (FTAI). In sperm evaluation, trajectory velocity, linear velocity, curvilinear velocity, and lateral head movement were higher (P < 0.05) in EY + SC at T0. At T90, while rectilinearity and linearity did not differ between EY and EY + SC (P > 0.05), the other parameters evaluated were higher in EY + SC. Similarly, the integrity of the plasma and acrosomal membranes (iPAM) was higher (P < 0.05) at T90 in EY + SC, but did not differ (P > 0.05) between the groups at T0. For O2- and HMP, the values were lower (P < 0.05) in EY + SC group in both moments; furthermore, EY + SC showed higher cleavage and blastocyst rates in IVF. Likewise, pregnancy rates by FTAI were higher (P < 0.05) in the EY + SC group. In conclusion, the addition of sodium caseinate into freezing extender improves sperm parameters of frozen-thawed bull semen and fertility rates on during in vitro and in vivo tests.

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The objective of this study was to evaluate the morphology, morphometry, and membrane integrity of epididymal spermatozoa of spotted pacas using spermatic cells collected from the epididymal tails of five animals. The flotation method using the ACP-123® and Botusemen Special® extenders was performed, and samples were stained in Diff-Quick and eosin-nigrosine. Descriptive statistics of data were obtained and Students t-test was performed. The morphology of 200 Diff-Quick-stained spermatozoa showed that they had an oval head with three vesicles in the acrosomal region, a midpiece, an elongated tail; moreover, 27% of the spermatozoa exhibited cellular defects. The morphometry of 100 sperm cells (analyzed with an optical microscope and the EZ Leica LAS software for Windows) presented the following measurements (mean ± SD): total length 43.87 ± 4.91 μm, head 7.54 ± 0.82 μm, midpiece 5.35 ± 0.83 μm, tail 30.72 ± 2.55 μm, and head width 5.30 ± 0.68 μm. Of the 2,000 cells stained with eosin-nigrosine for membrane integrity evaluation, 83.8% diluted in ACP-123® and 72.9% diluted in Botusemen® had intact membranes. The results of this study suggest that epididymal spermatozoa of pacas can be used in assisted reproduction programs; moreover, our study adds knowledge to the reproductive biology of wild animals, and encourages further research on the role of the three acrosomal vesicles present in this species.(AU)

Com o objetivo de avaliar a morfologia, a morfometria e a integridade de membrana dos espermatozoides epididimários de paca, células espermáticas oriundas da cauda do epidídimo foram obtidas de cinco animais pelo método de flutuação, utilizando os diluidores ACP-123 ® e Botusemen Special®, coradas em Panótico rápido e Eosina-Nigrosina. Os dados foram analisados por estatística descritiva e teste t de Student. A morfologia de 200 espermatozoides corados em Panótico rápido evidenciou que os mesmos possuíam: cabeça ovalada com três vesículas na região acrossomal, peça intermediária, cauda alongada, sendo os defeitos celulares de 27%. A morfometria de 100 células espermáticas (efetuada com microscópio óptico e softwares EZ Leica LAS de aquisição de imagens para sistemas operacionais Windows) apresentou as seguintes medidas (média ± d.p): comprimento total 43,87 ± 4,91 µm, cabeça 7,54 ± 0,82 µm, peça intermediária 5,35 ± 0,83 µm, cauda 30,72 ± 2,55 µm e largura da cabeça 5,30 ± 0,68 µm. Das 2.000 células coradas em Eosina-Nigrosina para avaliação da integridade da membrana, 83,8 % das diluídas em ACP 123 ® e 72,9 % das diluídas em Botusemen® estavam com as membranas intactas. Os resultados sugerem que espermatozoides epididimários de pacas podem ser utilizados em técnicas de reprodução assistida, agregam conhecimentos a esta área e suscitam novos estudos sobre o papel das três vesículas acrossomais características nesta espécie.(AU)

Assuntos

RESUMO

The objective of this study was to evaluate the morphology, morphometry, and membrane integrity of epididymal spermatozoa of spotted pacas using spermatic cells collected from the epididymal tails of five animals. The flotation method using the ACP-123® and Botusemen Special® extenders was performed, and samples were stained in Diff-Quick and eosin-nigrosine. Descriptive statistics of data were obtained and Students t-test was performed. The morphology of 200 Diff-Quick-stained spermatozoa showed that they had an oval head with three vesicles in the acrosomal region, a midpiece, an elongated tail; moreover, 27% of the spermatozoa exhibited cellular defects. The morphometry of 100 sperm cells (analyzed with an optical microscope and the EZ Leica LAS software for Windows) presented the following measurements (mean ± SD): total length 43.87 ± 4.91 μm, head 7.54 ± 0.82 μm, midpiece 5.35 ± 0.83 μm, tail 30.72 ± 2.55 μm, and head width 5.30 ± 0.68 μm. Of the 2,000 cells stained with eosin-nigrosine for membrane integrity evaluation, 83.8% diluted in ACP-123® and 72.9% diluted in Botusemen® had intact membranes. The results of this study suggest that epididymal spermatozoa of pacas can be used in assisted reproduction programs; moreover, our study adds knowledge to the reproductive biology of wild animals, and encourages further research on the role of the three acrosomal vesicles present in this species.

Com o objetivo de avaliar a morfologia, a morfometria e a integridade de membrana dos espermatozoides epididimários de paca, células espermáticas oriundas da cauda do epidídimo foram obtidas de cinco animais pelo método de flutuação, utilizando os diluidores ACP-123 ® e Botusemen Special®, coradas em Panótico rápido e Eosina-Nigrosina. Os dados foram analisados por estatística descritiva e teste t de Student. A morfologia de 200 espermatozoides corados em Panótico rápido evidenciou que os mesmos possuíam: cabeça ovalada com três vesículas na região acrossomal, peça intermediária, cauda alongada, sendo os defeitos celulares de 27%. A morfometria de 100 células espermáticas (efetuada com microscópio óptico e softwares EZ Leica LAS de aquisição de imagens para sistemas operacionais Windows) apresentou as seguintes medidas (média ± d.p): comprimento total 43,87 ± 4,91 µm, cabeça 7,54 ± 0,82 µm, peça intermediária 5,35 ± 0,83 µm, cauda 30,72 ± 2,55 µm e largura da cabeça 5,30 ± 0,68 µm. Das 2.000 células coradas em Eosina-Nigrosina para avaliação da integridade da membrana, 83,8 % das diluídas em ACP 123 ® e 72,9 % das diluídas em Botusemen® estavam com as membranas intactas. Os resultados sugerem que espermatozoides epididimários de pacas podem ser utilizados em técnicas de reprodução assistida, agregam conhecimentos a esta área e suscitam novos estudos sobre o papel das três vesículas acrossomais características nesta espécie.

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Background: In vitro embryo production (IVEP) allows the spread of superior animal genetics, but pregnancy rates show a high variability with this biotechnique. In the initial stage of pregnancy, progesterone plays a fundamental role in uterine preparation, acting on embryonic growth, implantation, and development. However, on the day of the IVEP transfer to the recipients, progesterone levels may be lower than that expected, influencing the uterine environment and, consequently, the pregnancy rate. Therefore, the objective of this study was to evaluate the pregnancy rate in heifers after the administration of injectable progesterone (P4) in the fixed-time embryo transfer (FTET) protocol. Materials, Methods & Results: The experiment was conducted inside a rural property near the city of Rio Branco, Acre, Brazil. The experimental group consisted of 232 animals, including 78 zebuine (Bos indicus) and 154 mixed (½ blood B. indicus and ½ blood B. taurus) animals, aged between 16 and 24 months, with a mean weight of 300 and 330 kg for zebuine and mixed animals, respectively. The selected animals were previously synchronized using the progesteroneestrogen-prostaglandin-estrogen protocol. Embryo transfer was performed on day 18 of the protocol, which was 9 days after the removal of intravaginal progesterone implant. On day 15 of the protocol, that is, 144 h (6 days) after the device removal, the animals were randomly distributed into two experimental groups: Control Group (CG; 0.5 mL of 0.9% saline solution, intramuscular) and Treated Group (P4G; 0.5 mL of injectable P4, 150 mg, intramuscular). Chi-square test was used for the statistical analysis of the pregnancy rate at a 5% probability. After 23 days of embryo transfer, pregnancy was diagnosed by ultrasonography. The general pregnancy rate, considering all groups (CG and P4G) and breeds included, was 55.17% (128/232). The pregnancy rates of the P4G and CG groups, regardless of breeds, were...

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Studies have shown that the use of equine chorionic gonadotropin (eCG), which binds both follicle stimulating hormone (FSH) and luteinizing hormone (LH) receptors, could modify the female reproductive tract. We, thus, aimed to quantify the messenger RNA (mRNA) abundance of genes related to cumulus-oocyte complexes (COCs) and embryo quality in Nelore cows (Bos taurus indicus) submitted to ovarian superstimulation using only FSH (FSH group; n = 10) or replacement of the last two doses of FSH by eCG (FSH/eCG group; n = 10). All animals were slaughtered and the ovarian antral follicles from both groups (10-14 mm in diameter) were aspirated for cumulus, oocyte and in vitro embryo production gene expression analysis. The relative mRNA abundance of 96 genes related to COCs development and embryo quality was measured by RT-qPCR. We found that oocytes are more affected by eCG use and that 35 genes involved in lipid metabolism, oxidative stress, transcriptional control, and cellular development were upregulated in the FSH/eCG group. In blastocysts, lipid metabolism seems to be the main pathway regulated by eCG use. We suggest that these multiple effects could be due to the ability of eCG to bind LHR and FSHR, which could activate multiple signal transduction pathways in the superstimulated ovary, further impacting the transcriptional profile of COCs and blastocysts.

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Estrus synchronization is a reproductive biotechnology used to improve artificial insemination or pairing through the manipulation of the estrous cycle at a desirable time. Employing this technique in captive pacas (Cuniculus paca L.) is important because it creates expectation of meeting the demand for paca meat and, consequently, reduces poaching. Thus, this research aims to verify the effect of a progestogen implant associated with two doses of eCG on the synchronization and induction of fertile estrus. Twenty-seven adult pacas were used, 18 non-pregnant females and nine males, divided into three groups. G1 and G2 females groups (treatments) received 1.5 mg Norgestomet and were injected intramuscularly, seven days later, with 0.13 mg of prostaglandin. After 24 hours the implants were removed and the animals immediately received 25 IU and 50 IU of ECG intramuscularly, respectively. The mating of the three groups took place on the same days. G3 females' group (control) showed estrus on different days after D0. Females under treatment displayed estrus only after removing the implant (D8). G1, G2, and G3 pregnancy rates were 100%, 66%, and 50%, respectively. Regarding births per parturition, 100% of G1 and G3 produced one offspring, while 50% of G2 produced two. Progestogen in the form of subcutaneous implants was effective in mimicking the luteal phase of the estrous cycle. After removal, implants favored the occurrence of a fertile estrus. As a conclusion, further studies must be conducted in order to establish in-depth possible association between 50 IU of eCG, and the occurrence of twin pregnancies.(AU)

A sincronização é uma biotécnica reprodutiva que melhora a porcentagem de cobertura por meio da manipulação do ciclo estral. Empregar esta biotécnica em pacas de cativeiro (Cuniculus paca L.) é importante, pois cria-se a expectativa de que a demanda pela carne seja atendida e a caça ilegal diminua. O objetivo da pesquisa foi verificar o efeito de implantes de progestágenos associados a duas doses de gonadotrofina coriônica equina (eCG) na sincronização e indução de cios férteis de pacas. Foram utilizadas 18 fêmeas não prenhas e nove machos, divididos em três grupos. Fêmeas do G1 e G2 receberam implantes com 1,5mg de Norgestomet e, sete dias depois, 0,13mg de prostaglandina via intramuscular (IM). No dia 8 (D8), foram retirados os implantes e G1 e G2 receberam 25 UI e 50 UI de eCG, IM, respectivamente; G3 foi o controle. O pareamento nos três grupos aconteceu nos mesmos dias. As fêmeas do G3 apresentaram cio alguns dias após o dia zero (D0). Fêmeas que receberam tratamento apresentaram cio só após a retirada do implante no dia 8 (D8). As taxas de prenhez de G1, G2 e G3 atingiram 100%, 66% e 50%, respectivamente. Em relação a filhotes por parto, 100% do G1 e G3 produziram uma cria, enquanto 50% do G2 produziram duas crias. O progestágeno do implante foi eficaz em mimetizar a fase lútea do ciclo estral. Após a remoção, o tratamento hormonal favoreceu a ocorrência de cio fértil. Outros estudos devem ser realizados a fim de estabelecer uma possível associação entre 50 UI de eCG e a ocorrência de gestações gemelares.(AU)

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RESUMO

Estrus synchronization is a reproductive biotechnology used to improve artificial insemination or pairing through the manipulation of the estrous cycle at a desirable time. Employing this technique in captive pacas (Cuniculus paca L.) is important because it creates expectation of meeting the demand for paca meat and, consequently, reduces poaching. Thus, this research aims to verify the effect of a progestogen implant associated with two doses of eCG on the synchronization and induction of fertile estrus. Twenty-seven adult pacas were used, 18 non-pregnant females and nine males, divided into three groups. G1 and G2 females groups (treatments) received 1.5 mg Norgestomet and were injected intramuscularly, seven days later, with 0.13 mg of prostaglandin. After 24 hours the implants were removed and the animals immediately received 25 IU and 50 IU of ECG intramuscularly, respectively. The mating of the three groups took place on the same days. G3 females' group (control) showed estrus on different days after D0. Females under treatment displayed estrus only after removing the implant (D8). G1, G2, and G3 pregnancy rates were 100%, 66%, and 50%, respectively. Regarding births per parturition, 100% of G1 and G3 produced one offspring, while 50% of G2 produced two. Progestogen in the form of subcutaneous implants was effective in mimicking the luteal phase of the estrous cycle. After removal, implants favored the occurrence of a fertile estrus. As a conclusion, further studies must be conducted in order to establish in-depth possible association between 50 IU of eCG, and the occurrence of twin pregnancies.(AU)

A sincronização é uma biotécnica reprodutiva que melhora a porcentagem de cobertura por meio da manipulação do ciclo estral. Empregar esta biotécnica em pacas de cativeiro (Cuniculus paca L.) é importante, pois cria-se a expectativa de que a demanda pela carne seja atendida e a caça ilegal diminua. O objetivo da pesquisa foi verificar o efeito de implantes de progestágenos associados a duas doses de gonadotrofina coriônica equina (eCG) na sincronização e indução de cios férteis de pacas. Foram utilizadas 18 fêmeas não prenhas e nove machos, divididos em três grupos. Fêmeas do G1 e G2 receberam implantes com 1,5mg de Norgestomet e, sete dias depois, 0,13mg de prostaglandina via intramuscular (IM). No dia 8 (D8), foram retirados os implantes e G1 e G2 receberam 25 UI e 50 UI de eCG, IM, respectivamente; G3 foi o controle. O pareamento nos três grupos aconteceu nos mesmos dias. As fêmeas do G3 apresentaram cio alguns dias após o dia zero (D0). Fêmeas que receberam tratamento apresentaram cio só após a retirada do implante no dia 8 (D8). As taxas de prenhez de G1, G2 e G3 atingiram 100%, 66% e 50%, respectivamente. Em relação a filhotes por parto, 100% do G1 e G3 produziram uma cria, enquanto 50% do G2 produziram duas crias. O progestágeno do implante foi eficaz em mimetizar a fase lútea do ciclo estral. Após a remoção, o tratamento hormonal favoreceu a ocorrência de cio fértil. Outros estudos devem ser realizados a fim de estabelecer uma possível associação entre 50 UI de eCG e a ocorrência de gestações gemelares.(AU)

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