RESUMO

Inúmeras são as vantagens da utilização da técnica de transferência de embriões (TE) em equinos. No entanto, alguns fatores podem afetar a taxa de recuperação embrionária: dia da colheita do embrião; condição uterina e idade da doadora; manejos reprodutivo, sanitário e nutricional; garanhão/qualidade do sêmen; habilidade do técnico; condições climáticas, número de ovulações e adaptação da doadora. O objetivo deste artigo é revisar os fatores que podem exercer influência sobre a taxa de recuperação embrionária tendo impacto direto nos índices reprodutivos de um programa de TE.(AU)

There are countless advantages of using the embryo transfer (ET) technique in horses. However, some factors may affect the embryonic recovery rate: day of embryo collection; uterine condition and donor age; reproductive, health and nutritional management; stallion/semen quality; skill of the technician; climatic conditions, number of ovulations and adaptation of the donor. The objective of this article is to review those factors that can influence the embryonic recovery rate, having a direct impact on the reproductive rates of an ET program.(AU)

Assuntos

RESUMO

A transferência de embriões equinos é uma biotecnologia que traz inúmeros benefícios reprodutivos para um haras. Entretanto, os índices reprodutivos obtidos numa estação de monta podem ser afetados por diversos fatores que interferem tanto na recuperação embrionária que normalmente são relacionados à doadora de embriões, quanto na taxa de gestação na receptora de embriões. O objetivo do presente artigo foi revisar os fatores relacionados à receptora de embriões em programas de transferência de embriões equinos.(AU)

Equine embryo transfer is a biotechnology that brings reproductive benefits to a stud farm. However, the reproductive rates obtained in a breeding season can be affected by several factors that interfere both in the embryonic recovery that are normally related to the embryo donor, and in the pregnancy rate in the embryo recipient. The aim of this article was to review the factors related to the recipient of embryos in equine embryo transfer programs.(AU)

Assuntos

RESUMO

The aim of the study was to correlate the spectral index of the right and left uterine arteries with equine placental development in mares with advanced pregnancies. We examined 32 multiparous Mangalarga Marchador mares with gestation of 150-240 days. During pregnancy, the pulsatility index (PI) and resistance index (RI) of the uterine arteries were obtained using spectral Doppler ultrasonography, and the combined uteroplacental thickness was obtained monthly using B-mode ultrasonography. The combined uteroplacental thickness correlated with gestational time of up to 13 years of age, and the significant difference was observed from the sixth month onwards. The CUPT stayed within the ideal measurements for this breed and for this gestational period. There was no correlation of CUPT with PI, however a negative and significant correlation of the RI was observed. The resistance index differed significantly among age groups, and the RI of the left uterine artery tended to decrease in all age groups. Furthermore, only RI differed significantly between the medians of gestatinal age. The left PI dropped in older mares. Thus, there an increased blood perfusion in the uterine arteries of mares with advanced pregnancies and among different age categories during placental and fetal physiological development.

Assuntos

RESUMO

The aim of this study was to evaluate whether the RI and PI values would help in choosing the best embryo recipient, and observe whether CL vascularization would influence P4 production. During the breeding season 2018/2019, the study was conducted using 35 mares, which is used for reference to collect data for the project on the day of embryo transfer. The utilized mares were divided into five groups followed by the day after ovulation, with D0 being the day of ovulation. Therefore, the five groups are as follows: D4-mares that were on the 4th post-ovulation day; D5-mares that were on the 5th post-ovulation day; and doing so successively for D6, D7 and D8. On the day of embryo transfer, the CL of the mares that selected as recipients was evaluated by B-mode and power flow mode ultrasonography and the right and left dorsal branches of the uterine arteries by spectral Doppler ultrasonography. Blood samples were taken on the day of the embryo transfer for a dosage of P4 concentration by radioimmunoassay. No statistical difference was found between the variables when the mares were separated into pregnant and non-pregnant mares, or when they were separated by age groups. When the groups of mares were compared by the day of embryo transfer, the statistical difference was found between the groups D5 × D6 (p = .0053) and D6 × D8 (p = .0036) in RI variable. In PI variable, the statistical difference was found between the groups D4 × D8 (p = .049), D5 × D6 (p = .0446) and D6 × D8 (p = .0024). We conclude that the mares with RI measurement of uterine arteries near 1.0 are correlated to mares with high CL vascularization and elevated P4 concentration.

Assuntos

RESUMO

The aim of this study was to evaluate the impact of successive bovine testicular punctures using different needle sizes. Fifteen bulls were submitted to testicular needle aspiration (TNA) in the left and right testis using 18-gauge (40×12mm) or 22-gauge (25×7mm) needles, respectively, once every 30 days. Animals were randomly divided into three groups, which were submitted to bilateral orchiectomy two days after the last puncture. Group 1 (G1): only one puncture (n=5); Group 2 (G2): three consecutive punctures in a period of three months (n=5); Group 3 (G3): six consecutive punctures in a period of 6 months (n=5). Fragments from the medial portion of the testicular parenchyma were excised and fixed in Bouin's fluid for histological analysis. No differences were observed in the percentage of seminiferous tubules degeneration between G1, G2 and G3 (P>0.05). Higher amounts of erythrocyte were found in G1 and G2 groups compared to G3, in the intra- and intertubular tissue (P<0.05). There was no interaction between the needle gauge and the occurrence of testicular damage in animals submitted to one (G1) or three (G2) punctures. However, a higher percentage of tubular degeneration was associated to 18-gauge compared to 22-gauge fine needles in G3. In conclusion, multiple testicular needle aspiration can be safely conducted using fine needles. Large needles are recommended only for a single TNA, since multiple punctures may result in increased tubular degeneration and compromise testicular architecture and functionality.

RESUMO

The aim of this study was to evaluate the impact of successive bovine testicular punctures using different needle sizes. Fifteen bulls were submitted to testicular needle aspiration (TNA) in the left and right testis using 18-gauge (40×12mm) or 22-gauge (25×7mm) needles, respectively, once every 30 days. Animals were randomly divided into three groups, which were submitted to bilateral orchiectomy two days after the last puncture. Group 1 (G1): only one puncture (n=5); Group 2 (G2): three consecutive punctures in a period of three months (n=5); Group 3 (G3): six consecutive punctures in a period of 6 months (n=5). Fragments from the medial portion of the testicular parenchyma were excised and fixed in Bouin’s fluid for histological analysis. No differences were observed in the percentage of seminiferous tubules degeneration between G1, G2 and G3 (P>0.05). Higher amounts of erythrocyte were found in G1 and G2 groups compared to G3, in the intra- and intertubular tissue (P<0.05). There was no interaction between the needle gauge and the occurrence of testicular damage in animals submitted to one (G1) or three (G2) punctures. However, a higher percentage of tubular degeneration was associated to 18-gauge compared to 22-gauge fine needles in G3. In conclusion, multiple testicular needle aspiration can be safely conducted using fine needles. Large needles are recommended only for a single TNA, since multiple punctures may result in increased tubular degeneration and compromise testicular architecture and functionality.

Assuntos

RESUMO

The aim of this study was to evaluate the impact of successive bovine testicular punctures using different needle sizes. Fifteen bulls were submitted to testicular needle aspiration (TNA) in the left and right testis using 18-gauge (40×12mm) or 22-gauge (25×7mm) needles, respectively, once every 30 days. Animals were randomly divided into three groups, which were submitted to bilateral orchiectomy two days after the last puncture. Group 1 (G1): only one puncture (n=5); Group 2 (G2): three consecutive punctures in a period of three months (n=5); Group 3 (G3): six consecutive punctures in a period of 6 months (n=5). Fragments from the medial portion of the testicular parenchyma were excised and fixed in Bouins fluid for histological analysis. No differences were observed in the percentage of seminiferous tubules degeneration between G1, G2 and G3 (P>0.05). Higher amounts of erythrocyte were found in G1 and G2 groups compared to G3, in the intra- and intertubular tissue (P<0.05). There was no interaction between the needle gauge and the occurrence of testicular damage in animals submitted to one (G1) or three (G2) punctures. However, a higher percentage of tubular degeneration was associated to 18-gauge compared to 22-gauge fine needles in G3. In conclusion, multiple testicular needle aspiration can be safely conducted using fine needles. Large needles are recommended only for a single TNA, since multiple punctures may result in increased tubular degeneration and compromise testicular architecture and functionality.(AU)

Assuntos

RESUMO

Protocols for cooling or freezing goat semen usually recommend centrifugation for seminal plasma removal. However, little is known about the effect of this process on goat sperm viability and functionality. The present study evaluated the effects of centrifugation force on the plasma membrane, acrosomes, and DNA integrity of goat semen. Four ejaculates from each of the four different Anglo Nubian male goats were used. Semen samples were obtained using artificial vagina, and immediately after collection, ejaculates were diluted using Ringer's sodium lactate solution and split into three groups: Control (CG, without centrifugation), G1 (centrifugation 600 x g/10 min), G2 (centrifugation 1200 x g/10 min). After centrifugation, seminal plasma was removed, the sperm pellets were resuspended using Tris-egg yolk extender (80 x 106 spermatozoa/mL) and the sperm morphology was analyzed. Samples were cooled at 5°C for 5, 24, 36, and 48 h and then sperm plasma membrane and acrosome integrity (PMAI, %) and sperm DNA fragmentation index (SDF, %) were evaluated at each time-point, using a flow cytometer. Additionally, sperm movement was determined using computer semen analysis (CASA) after 5, 24, and 48 h of refrigeration period. The semen centrifugation did not induce additional sperm morphology defect or reduction in sperm kinetics in the experimental groups. Differences were not observed (p > 0.05) in PMAI and SDF among different groups, in any of each time-point of the cooling process. In conclusion, centrifugation, even at high speeds, did not affect goat sperm integrity and functionality when submitted to refrigeration process. (AU)

A maior parte dos protocolos de refrigeração e criopreservação do sêmen caprino recomenda o uso de centrifugação para remoção do plasma seminal. No entanto, não existe consenso sobre o risco que esse tipo de processamento pode ocasionar à viabilidade espermática. Nesse contexto, o presente trabalho investigou os possíveis efeitos deletérios da centrifugação sobre a integridade estrutural e DNA de espermatozoides caprinos. Para a pesquisa foram selecionados quatro reprodutores para colheita de sêmen (n = 4 ejaculados/bode). Cada ejaculado foi fracionado em três alíquotas iguais, diluídas em ringer e divididas em três grupos: Controle (GC, não centrifugado), G1 (centrifugação a 600 g/10 minutos) e G2 (centrifugação a 1200 g/10 minutos). As amostras seminais por grupo foram diluídas em meio Tris gema respeitando-se a concentração final de 80 milhões de espermatozoides/mL e foram submetidas à avaliação de morfologia espermática. Todas as amostras foram acondicionadas a 5°C, sendo analisadas nos momentos 5, 24, 36 e 48 horas do processo de refrigeração por meio da avaliação da integridade de membrana plasmática e acrossomal (MPAI, %) e índice de fragmentação de DNA (IDF, %). Adicionalmente, a cinética espermática foi avaliada com o emprego de um sistema computadorizado de análise (CASA) nos momentos 5, 24 e 48 horas da refrigeração. A centrifugação não induziu a manifestação de defeitos morfológicos ou redução significativa da cinética de espermatozoides caprinos. Não foram observadas diferenças para a integridade de membrana plasmática e para o índice de fragmentação de DNA quando comparados, respectivamente, GC, G1 e G2 em cada um dos quatro momentos experimentais. Conclui-se que mesmo quando empregadas altas forças de rotação não ocorre lesão à ultraestrutura dos espermatozoides caprinos submetidos ao processo de refrigeração.(AU)

Assuntos

RESUMO

Protocols for cooling or freezing goat semen usually recommend centrifugation for seminal plasma removal. However, little is known about the effect of this process on goat sperm viability and functionality. The present study evaluated the effects of centrifugation force on the plasma membrane, acrosomes, and DNA integrity of goat semen. Four ejaculates from each of the four different Anglo Nubian male goats were used. Semen samples were obtained using artificial vagina, and immediately after collection, ejaculates were diluted using Ringer's sodium lactate solution and split into three groups: Control (CG, without centrifugation), G1 (centrifugation 600 x g/10 min), G2 (centrifugation 1200 x g/10 min). After centrifugation, seminal plasma was removed, the sperm pellets were resuspended using Tris-egg yolk extender (80 x 106 spermatozoa/mL) and the sperm morphology was analyzed. Samples were cooled at 5°C for 5, 24, 36, and 48 h and then sperm plasma membrane and acrosome integrity (PMAI, %) and sperm DNA fragmentation index (SDF, %) were evaluated at each time-point, using a flow cytometer. Additionally, sperm movement was determined using computer semen analysis (CASA) after 5, 24, and 48 h of refrigeration period. The semen centrifugation did not induce additional sperm morphology defect or reduction in sperm kinetics in the experimental groups. Differences were not observed (p > 0.05) in PMAI and SDF among different groups, in any of each time-point of the cooling process. In conclusion, centrifugation, even at high speeds, did not affect goat sperm integrity and functionality when submitted to refrigeration process. (AU)

A maior parte dos protocolos de refrigeração e criopreservação do sêmen caprino recomenda o uso de centrifugação para remoção do plasma seminal. No entanto, não existe consenso sobre o risco que esse tipo de processamento pode ocasionar à viabilidade espermática. Nesse contexto, o presente trabalho investigou os possíveis efeitos deletérios da centrifugação sobre a integridade estrutural e DNA de espermatozoides caprinos. Para a pesquisa foram selecionados quatro reprodutores para colheita de sêmen (n = 4 ejaculados/bode). Cada ejaculado foi fracionado em três alíquotas iguais, diluídas em ringer e divididas em três grupos: Controle (GC, não centrifugado), G1 (centrifugação a 600 g/10 minutos) e G2 (centrifugação a 1200 g/10 minutos). As amostras seminais por grupo foram diluídas em meio Tris gema respeitando-se a concentração final de 80 milhões de espermatozoides/mL e foram submetidas à avaliação de morfologia espermática. Todas as amostras foram acondicionadas a 5°C, sendo analisadas nos momentos 5, 24, 36 e 48 horas do processo de refrigeração por meio da avaliação da integridade de membrana plasmática e acrossomal (MPAI, %) e índice de fragmentação de DNA (IDF, %). Adicionalmente, a cinética espermática foi avaliada com o emprego de um sistema computadorizado de análise (CASA) nos momentos 5, 24 e 48 horas da refrigeração. A centrifugação não induziu a manifestação de defeitos morfológicos ou redução significativa da cinética de espermatozoides caprinos. Não foram observadas diferenças para a integridade de membrana plasmática e para o índice de fragmentação de DNA quando comparados, respectivamente, GC, G1 e G2 em cada um dos quatro momentos experimentais. Conclui-se que mesmo quando empregadas altas forças de rotação não ocorre lesão à ultraestrutura dos espermatozoides caprinos submetidos ao processo de refrigeração.(AU)

Assuntos

RESUMO

Protocols for cooling or freezing goat semen usually recommend centrifugation for seminal plasma removal. However, little is known about the effect of this process on goat sperm viability and functionality. The present study evaluated the effects of centrifugation force on the plasma membrane, acrosomes, and DNA integrity of goat semen. Four ejaculates from each of the four different Anglo Nubian male goats were used. Semen samples were obtained using artificial vagina, and immediately after collection, ejaculates were diluted using Ringers sodium lactate solution and split into three groups: Control (CG, without centrifugation), G1 (centrifugation 600 x g/10 min), G2 (centrifugation 1200 x g/10 min). After centrifugation, seminal plasma was removed, the sperm pellets were resuspended using Tris-egg yolk extender (80 x 106 spermatozoa/mL) and the sperm morphology was analyzed. Samples were cooled at 5°C for 5, 24, 36, and 48 h and then sperm plasma membrane and acrosome integrity (PMAI, %) and sperm DNA fragmentation index (SDF, %) were evaluated at each time-point, using a flow cytometer. Additionally, sperm movement was determined using computer semen analysis (CASA) after 5, 24, and 48 h of refrigeration period. The semen centrifugation did not induce additional sperm morphology defect or reduction in sperm kinetics in the experimental groups. Differences were not observed

A maior parte dos protocolos de refrigeração e criopreservação do sêmen caprino recomenda o uso de centrifugação para remoção do plasma seminal. No entanto, não existe consenso sobre o risco que esse tipo de processamento pode ocasionar à viabilidade espermática. Nesse contexto, o presente trabalho investigou os possíveis efeitos deletérios da centrifugação sobre a integridade estrutural e DNA de espermatozoides caprinos. Para a pesquisa foram selecionados quatro reprodutores para colheita de sêmen (n = 4 ejaculados/bode). Cada ejaculado foi fracionado em três alíquotas iguais, diluídas em ringer e divididas em três grupos: Controle (GC, não centrifugado), G1 (centrifugação a 600 g/10 minutos) e G2 (centrifugação a 1200 g/10 minutos). As amostras seminais por grupo foram diluídas em meio Tris gema respeitando-se a concentração final de 80 milhões de espermatozoides/mL e foram submetidas à avaliação de morfologia espermática. Todas as amostras foram acondicionadas a 5°C, sendo analisadas nos momentos 5, 24, 36 e 48 horas do processo de refrigeração por meio da avaliação da integridade de membrana plasmática e acrossomal (MPAI, %) e índice de fragmentação de DNA (IDF, %). Adicionalmente, a cinética espermática foi avaliada com o emprego de um sistema computadorizado de análise (CASA) nos momentos 5, 24 e 48 horas da refrigeração. A centrifugação não induziu a manifestação de defe