Efficiency and accuracy of different ovulation inducers after progesterone device removal in crossbred multiparous cows / Eficiência e acurácia de diferentes indutores de ovulação após a remoção do dispositivo de progesterona em vacas mestiças multíparas

The aim of this study was to verify the efficiency and ovulation time after the administration of different inducers for synchronization of ovulation in beef cows. One hundred and eight non-lactating cows were distributed into the control group (CG; untreated; n=28), estradiol benzoate (EB) group (EBG; n=28); 17 beta-estradiol (17ßE) group (17ßEG; n=28), and deslorelin (DES) group (DESG; n=24). On day minus 11 (D-11) of the protocol, the CG underwent application of cloprostenol and ultrasound examination (US); on D0, progesterone (P4) was inserted plus EB; on D7, cloprostenol was applied; on D9, P4 was removed and cloprostenol plus 400 IU of equine chorionic gonadotropin (eCG) was injected. The EBG was subjected to treatment identical to that of the CG, except on D10, when the cows received EB. The 17ßE was subjected to the same protocol used in the CG except for the administration of 17ßE on D10. And, the DESG was subjected to the same treatment as the CG, except on D10, when the group received DES acetate. Twelve hours after the administration of EB, 17ßE and DES, ovarian US were performed every 6 hours. The preovulatory follicle (POF) diameters measured before ovulation were 19.5; 14.7; 18.7 and 19.8 mm respectively for CG, EBG, 17ßEG and DESG; and the time intervals between inducer application and ovulation were 20.2; 18.9; 21.0 and 22.5 hours respectively. In conclusion, all ovulation inducers were efficient in promoting ovulation; the inducers caused ovulation between 18.9 and 22.5 hours; EB promoted ovulation in a shorter time (P<0.05); 17ßE and DES showed greater variation in application/ovulation time between groups.

O objetivo do estudo foi verificar a eficiência e a ovulação após a administração de diferentes indutores para a sincronização da ovulação em vacas de corte. Cento e oito vacas não-lactantes foram distribuídas em grupo controle (GC; não tratadas; n=28); grupo benzoato de estradiol (BE) (GBE; n=28); grupo 17 beta-estradiol (17ßE) (G17ßE; n=28) e grupo deslorelina (DES) (GDES; n=24). No dia menos 11 (D-11) do protocolo, o GC recebeu cloprostenol e exame ultrassonográfico (US); ao D0, dispositivo de progesterona (P4) foi inserido mais BE; ao D7, cloprostenol foi aplicado; ao D9, a P4 foi removida e cloprostenol mais 400 UI de gonadotrofina coriônica equina (eCG) foi injetada. O GBE foi submetido a tratamento idêntico ao do GC, exceto ao D10, quando as vacas receberam BE. o G17ßE foi submetido ao mesmo protocolo usado no CG exceto pela administração de 17ßE ao D10. E, o GDES foi submetido ao mesmo tratamento que o CG, exceto ao D10, quando o grupo recebeu o acetato de DES. Doze horas após a administração de BE, 17ßE e DES, US ovarianos foram realizados a cada 6 horas. O diâmetro do folículo pré-ovulatório (FPO) medido antes da ovulação foi de 19,5; 14,7; 18,7 e 19,8 mm respectivamente para GC, GBE, G17ßE e GDES; e o intervalo de tempo entre a aplicação do indutor e ovulação foi 20,2; 18,9; 21;0 e 22,5 horas respectivamente. Em conclusão, todos os indutores da ovulação foram eficientes em promover a ovulação; os indutores acarretaram ovulação entre 18,9 e 22,5 horas; o BE promoveu a ovulação em menor espaço de tempo (P<0,05); 17ßE e DES demonstraram maior variação em aplicação/tempo de ovulação entre os grupos.

Evaluation of corpus luteum vascularization in recipient mares by using color Doppler ultrasound

Background: Embryo transfer is one of the most commonly used reproductive biotechnique. The success of embryotransfer is also affected by the synchrony of estrus and ovulation between donor and recipient animals. In horse reproduction, ultrasonography has been used, among other purposes, to diagnose early pregnancy. However, only the color Dopplerimaging mode makes it possible to evaluate the vascular architecture and the hemodynamic aspects of the vessels in severalorgans, especially the corpus luteum. The objective of this study was to evaluate, based on the color Doppler ultrasound,the corpus luteum vascularization and function from recipient mares at embryo transfer timing.Materials, Methods & Results: Mangalarga Machador mares from 5 to 10-year-old and a range of live weights of between350 to 450 kg were used for this experiment, kept in pasture-based on mombaça grass (Panicum maximum) and were givenad libitum access to water and mineral supplementation. The animals (n = 15) were gynecologically examined and uterineconsistency was evaluated by rectal palpation the same operator using an ultrasound system (SonoScape®) with a lineartransducer, and operating frequency ranging from 5 to 10 Mhz. The uterine tone was classified between grades 1 and 4 andsubjected to ovulation induction. The objective and subjective vascular perfusion of the corpus luteum was evaluated bycolor Doppler ultrasound on the day of embryo transfer and endometrium. The determination progesterone concentrationon the day of the embryo transfer was performed by direct chemiluminescence assay. The arcsine (√P/100) transformation was applied to the percentage data, and the results were expressed as mean (.) ± standard error of the mean (SEM).Further, the assumptions of normality and homoscedasticity were verified, respectively, based on the Shapiro-Wilk and...(AU)

Evaluation of corpus luteum vascularization in recipient mares by using color Doppler ultrasound

Background: Embryo transfer is one of the most commonly used reproductive biotechnique. The success of embryotransfer is also affected by the synchrony of estrus and ovulation between donor and recipient animals. In horse reproduction, ultrasonography has been used, among other purposes, to diagnose early pregnancy. However, only the color Dopplerimaging mode makes it possible to evaluate the vascular architecture and the hemodynamic aspects of the vessels in severalorgans, especially the corpus luteum. The objective of this study was to evaluate, based on the color Doppler ultrasound,the corpus luteum vascularization and function from recipient mares at embryo transfer timing.Materials, Methods & Results: Mangalarga Machador mares from 5 to 10-year-old and a range of live weights of between350 to 450 kg were used for this experiment, kept in pasture-based on mombaça grass (Panicum maximum) and were givenad libitum access to water and mineral supplementation. The animals (n = 15) were gynecologically examined and uterineconsistency was evaluated by rectal palpation the same operator using an ultrasound system (SonoScape®) with a lineartransducer, and operating frequency ranging from 5 to 10 Mhz. The uterine tone was classified between grades 1 and 4 andsubjected to ovulation induction. The objective and subjective vascular perfusion of the corpus luteum was evaluated bycolor Doppler ultrasound on the day of embryo transfer and endometrium. The determination progesterone concentrationon the day of the embryo transfer was performed by direct chemiluminescence assay. The arcsine (√P/100) transformation was applied to the percentage data, and the results were expressed as mean (.) ± standard error of the mean (SEM).Further, the assumptions of normality and homoscedasticity were verified, respectively, based on the Shapiro-Wilk and...

Contracepção em felinos domésticos: novas abordagens / Contraception in domestic felines: new approaches

A população de gatos domésticos já excede a de cães em muitos países do mundo e o crescimentopopulacional dos gatos domésticos domiciliados cresce paralelamente ao da população de animais abandonados.Esse fato nos coloca frente a uma problemática referente a procriação excessiva e a todas as consequênciasrelativas a essa situação. A escolha de métodos contraceptivos adequados para a espécie felina ainda necessitamde experimentos controlados e de observações a longo prazo para a determinação das vantagens e desvantagensde determinados procedimentos e do conhecimento dos mecanismos de ação de fármacos com indicaçãocontraceptiva. A proposta dessa revisão de literatura é abordar os contraceptivos mais utilizados nos felinosdomésticos, enfatizando o mecanismo de ação, dosagens utilizadas, vantagens e desvantagens de cada fármacoconsiderado.(AU)

The number of domestic cats already exceeds dog population in many countries around the world. Alsothe number of housed cats grows in the same scale of abandoned animals. This fact makes us face the problem ofexcessive procreation and all consequences related this issue. The choice of an appropriated contraceptivemethod for felines still needs controlled experiments and long term observations in order to determine all prosand cons of some procedures and to increase the knowledge regarding the action mechanism of drugs that mayact as contraceptive. This review objective is to approach the most used contraceptive treatments in domesticfelines, emphasizing the action mechanism, recommended dosage, pros and cons from each contraceptivemethods.(AU)

Contracepção em felinos domésticos: novas abordagens / Contraception in domestic felines: new approaches

A população de gatos domésticos já excede a de cães em muitos países do mundo e o crescimentopopulacional dos gatos domésticos domiciliados cresce paralelamente ao da população de animais abandonados.Esse fato nos coloca frente a uma problemática referente a procriação excessiva e a todas as consequênciasrelativas a essa situação. A escolha de métodos contraceptivos adequados para a espécie felina ainda necessitamde experimentos controlados e de observações a longo prazo para a determinação das vantagens e desvantagensde determinados procedimentos e do conhecimento dos mecanismos de ação de fármacos com indicaçãocontraceptiva. A proposta dessa revisão de literatura é abordar os contraceptivos mais utilizados nos felinosdomésticos, enfatizando o mecanismo de ação, dosagens utilizadas, vantagens e desvantagens de cada fármacoconsiderado.

The number of domestic cats already exceeds dog population in many countries around the world. Alsothe number of housed cats grows in the same scale of abandoned animals. This fact makes us face the problem ofexcessive procreation and all consequences related this issue. The choice of an appropriated contraceptivemethod for felines still needs controlled experiments and long term observations in order to determine all prosand cons of some procedures and to increase the knowledge regarding the action mechanism of drugs that mayact as contraceptive. This review objective is to approach the most used contraceptive treatments in domesticfelines, emphasizing the action mechanism, recommended dosage, pros and cons from each contraceptivemethods.

Induction of ovulation in quarter horse mares through the use of deslorelin acetate and human chorionic gonadotrophin (hCG)

The aim this study was to compare two protocols of induction for ovulation by desloreline acetate and hCG in Quarter Horse mares. The choice of the animals was based on the observations by the estrus, by rectal palpation of the ovaries and by ultrassonography of the follicular dynamics. After estrus detection and follicle control, the measurement of the follicles and the classification of uterus were carried out. The animals that had dominant follicle (diameter more than 35 mm) and swollen uterus were used. In these conditions, the mares received hCG or desloreline acetate. Once ovulation occurred, the artificial insemination was carried. Two groups were performed: G1 (20 animals) received 1.5 mg desloreline acetate and G2 (20 animals) received 1700 IU of hCG. Following 6h intervals, the control follicular was performed by ultrasonography. The follicular average diameter was 42.6 cm for the groups and set up a score of 0 to 3 of uterine edema displayed by the device as well as the time of ovulation. In conclusion, the desloreline acetate showed better performance than hCG, because the ovulation was induced in less time (nine hours than hCG) (p<0.05).The pregnancy rate was 80 and 75 percent, respectively in G1 and G2.