Correlation of maternal concentrations of plasma testosterone with fetal sex in horses / Correlação das concentrações plasmáticas de testosterona materna com o sexo fetal em equinos

ABSTRACT: The objectives of this study were to evaluate the correlation of fetal sex and plasma testosterone concentrations between the 5th and 8th months of pregnancy in mares and to verify the applicability of this test to predict fetal sex. Blood samples were collected from 21 mares at 30-day intervals of between 150 and 240 days of pregnancy. Plasma testosterone was determined by radioimmunoassay and the sex of the foals confirmed at birth. The levels of maternal testosterone were higher in mares carrying female fetuses at months 5 and 8 (P < 0.05). Limit values were determined by analyzing the receiver operating characteristic (ROC) estimates: 35.5 pg/mL and 40 pg/mL for the 5th and 8th month, respectively. For the mares with plasma testosterone values equal to or above the threshold, gestation of female foals was predicted, and for those with plasma testosterone below the threshold values pregnancy of male foals was predicted. In the 5th month, the predictive values for male and female fetuses were 70% and 88.9%, respectively; the detection rates were 87.5% and 72.7%, and the total accuracy of the examination was 78.9%. In the 8th month, the predictive values for male and female fetuses were 80% and 90%, respectively; the detection rates were 88.9% and 81.8%, and the total accuracy of the examination was 85%. It was concluded that there was a correlation between fetal sex and plasma testosterone concentrations in pregnant mares. Prediction of fetal sex based on plasma concentrations of maternal testosterone can be performed in months 5 and 8 with 78.9% and 85% accuracy, respectively.

RESUMO: Os objetivos do estudo foram avaliar a correlação do sexo fetal com as concentrações plasmáticas de testosterona entre o 5° e o 8º mês de gestação na égua e verificar a aplicabilidade deste exame para a predição do sexo fetal. Amostras de sangue foram coletadas de 21 éguas, com intervalos de 30 dias, entre 150 e 240 dias de gestação. A testosterona plasmática foi determinada por radioimunoensaio e o sexo dos potros foi confirmado ao nascimento. Os valores de testosterona materna foram superiores nas éguas gestando fetos fêmeas aos cinco e oito meses (P< 0.05). Através da análise da curva ROC (receiver operating characteristic) foram determinados valores limites de 35,5 pg/mL e 40 pg/mL para o 5º e o 8° mês, respectivamente. Éguas com testosterona plasmática igual ou acima dos valores limites foram preditas como gestando fêmeas e éguas com testosterona plasmática abaixo dos valores limites foram preditas como gestando machos. Aos cinco meses, os valores preditivos para fetos machos e fêmeas foram 70% e 88,9%, respectivamente; as taxas de detecção foram 87,5% e 72,7% e a acurácia total do exame foi de 78,9%. Aos oito meses, os valores preditivos para fetos machos e fêmeas foram 80% e 90%, respectivamente; as taxas de detecção foram 88,9% e 81,8% e a acurácia total do exame foi de 85%. Conclui-se que houve correlação entre o sexo fetal e as concentrações de testosterona plasmática em éguas prenhes. A predição do sexo fetal baseada nas concentrações plasmáticas de testosterona materna pode ser realizada aos cinco e oito meses de gestação com 78,9% e 85% de acurácia, respectivamente.

In vitro and in vivo fertilization potential of cryopreserved spermatozoa from bull epididymides stored for up to 30 hours at ambient temperature (18 °C-20 °C).

The aims of this study were to compare the viability and in vivo and in vitro fertilization potential post-thaw sperm collected at different times postorchiectomy from bull epididymides (EP) at 18 °C to 20 °C, with those of semen collected by electroejaculation (EJ) from the same bulls. Semen samples were collected by EJ from 10 Zebu bulls and cryopreserved. A week later 20 epididymides from these bulls were obtained by orchiectomy and randomly divided into five groups (G) to be maintained at ambient temperature for 6, 12, 18, 24, and 30 hours before sperm recovery by retrograde flow. The sperm were cryopreserved, and post-thaw parameters were determined by both computer-assisted sperm analysis and morphologic analysis. In vitro fertilization of oocytes was performed to assess the cleavage rate, blastocyst rate, total number of cells, and hatching rate of embryos. The G30 sperm samples were also used for fixed time artificial insemination (FTAI) of Zebu heifers (n = 10). The results of post-thaw sperm viability showed that total and progressive motility and plasma membrane integrity were lower in sperm in which cryopreservation was delayed for 30 hours, showing a negative correlation of these parameters with delay before cryopreservation. In all groups, it was possible to obtain viable embryos, and embryos from G6 samples had more cells than the other groups. The greatest embryo production rates were observed in G6, G12 and G18 (27.2 to 32.2%) and it was significantly lower in G24 and G30 samples. For EJ, many individual variations were observed in embryo production potential between bulls. G30 samples, with only 5.2% of post-thaw progressive motility, were able to fertilize and produced a pregnancy. To the authors' knowledge, this is the first time in vitro embryos up to 8 days of development and a pregnancy after FTAI have been produced with sperm from bull epididymides that had been stored at 18 °C to 20 °C for up to 30 hours.

Melanocitoma dérmico fibroso em bovino: relato de caso / Fibrous skin melanocitome in cattle: a case report / Melanocitoma dérmico fibroso en bovino: relato de caso

Melanomas e melanocitomas são neoplasias de melanoblastos e melanócitos. Neoplasias melanocíticas raramente são observadas em bovinos sendo frequentemente confundidas com outros aumentos de volume ou neoplasias, apresentando comportamento predominantemente benigno. É relatado um caso de melanocitoma em uma novilha da raça Jersey de oito meses de idade, descrevendo-se seu aspecto macro e microscópico. A neoplasia foi integralmente retirada por meio cirúrgico sem complicações ou recidivas até o momento. Ressalta-se a importância para este distúrbio, principalmente para o seu diagnóstico diferencial e a resolução relativamente descomplicada para o médico veterinário.(AU)

Melanoma and meloanocitome are melanoblast and melanocyte tumors. Melanocytic neoplasms are rarely observed in cattle and can be confused with other volume increases or neoplasms. Bovine melanoma is predominantly benign. One case of melanocitome in an 8-month old Jersey heifer is reported, describing their macro- and microscopic appearance. The tumor was completely removed by surgical means without complications. The importance of this disorder must be emphasized, especially for the differential diagnosis and the relatively uncomplicated resolution to the veterinarian.(AU)

Melanomas y melanocitomas son neoplasias de melanoblastos y melanocitos. Neoplasias melanocíticas son raramente observadas en bovino, a menudo se confunde con otros aumentos de volumen o neoplasias, presentando comportamiento predominantemente benigno. Es relatado un caso de malenocitoma en una novilla de la raza Jersey con ocho meses de edad, describiéndose su aspecto macro y microscópico. La neoplasia fue extirpada completamente por medio quirúrgico sin complicaciones o recidivas hasta el momento. Se resalta la importancia para este disturbio, especialmente para su diagnóstico diferencial y la resolución relativamente poco complicada para el médico veterinario.(AU)

Dois diluentes comerciais na criopreservação de espermatozoides do epidídimo de touros / Two commercial extenders for cryopreservation of epididymal bull sperm

A recuperação e a criopreservação de espermatozoides do epidídimo constituem alternativas viáveis para a preservação de material genético de animais valiosos. O objetivo deste estudo foi comparar o desempenho de dois diluentes comerciais Botu-Bov(r) (BB) e Bovimix(r) (BV), sobre a viabilidade pós-descongelação de espermatozoides do epidídimo de touros Tabapuã (Bos taurus indicus) pós-castração. Os espermatozoides foram colhidos da cauda de 20 epidídimos utilizando a técnica de fluxo retrógrado, centrifugados e diluídos com BB ou BV para posterior criopreservação a -196°C. Após a descongelação, as amostras foram avaliadas utilizando a análise computadorizada (CASA) e por análises microscópicas para a determinação da integridade de membranas plasmáticas, acrossomal e morfologia espermática. A avaliação estatística dos dados foi realizada pela análise de variância (ANOVA) com o pós-teste de comparações múltiplas de Tukey-Kramer, com nível de significância (P<0,05). Os resultados do movimento espermático avaliado pelo CASA, não diferiram para o diluente BB e BV. Também não foi observada diferença significativa entre os grupos no percentual de espermatozoides morfologicamente deformados, defeitos de acrossoma e espermatozoides com membrana plasmática íntegra após o descongelamento. Conclui-se que ambos os diluentes (BB e BV) são eficientes e podem ser utilizados na tecnologia do congelamento de espermatozoides colhidos da cauda do epidídimo de touros, não apresentando diferença na viabilidade espermática para os parâmetros estudados.

Recovery and cryopreservation of epididymal sperm is a viable alternative for preservation of genetically valuable animals. The aim of this study was to verify and to compare the effect of two commercial extenders for conventional semen on post-thawing viability of bovine epididymal sperm. For this purpose, the spermatozoa was recovered from the tail of 20 epididymis of Tabapuã bulls (Bos Taurus indicus) using retrograde flow method. After sperm recovery, the cells were centrifuged and divided for dilution with the diluents Botu-Bov(r) (BB) or Bovimix(r) (BV) for cryopreservation at -196°C. After thawing, all samples were evaluated using computer assisted sperm analysis (CASA), and by microscopic analysis for determination of integrity of plasma and acrossomal membrane and morphology. Statistical evaluation was performed by analysis of variance (ANOVA) with post-test for multiple comparisons, the Tukey-Kramer test, with significance level (P<0.05). The results of the sperm movement for diluent BB and BV evaluated with CASA, showed no difference for both (P>0.05). There was also no difference between the percentage of deformed sperm, acrosome defects and the sperm with intact plasma membrane after thawing with BB or BV. We conclude that both extenders (BB and BV) are efficient and can be used for freezing sperm collected from the epididymis of bulls, showing no difference for all the parameters studied.