Surface temperature of ewes during estrous cycle measured by infrared thermography.

The use of infrared thermography has not been used previously to assist sheep reproduction. The aim of this study was evaluate the viability of infrared thermography to identify body surface temperature patterns during ewes' estrous cycle. The estrous cycles of 20 Santa Ines ewes were synchronized through hormone treatment (progesterone implant). The ewes were submitted to measurements of body temperature (rectal and vaginal) with a digital thermometer and surface temperature of the anus, vulva, muzzle, left ear and left eye by infrared thermography. Temperature and humidity of the environment and wet-bulb globe temperature (WBGT) were measured. After the progesterone implant's removal, the follicular dynamic was evaluated daily during five days with ultrasound. The estrous cycle was separated into six phases to facilitate interpretation of the differences in body temperatures in each period. Phase 1 was the period before estrous synchronization, phase 2 was the beginning of estrous synchronization, phase 3 was the intermediate period and end of synchronization, phase 4 was the period of estrus manifestations, phase 5 was the ovulation period, and phase 6 was the post-ovulatory period. There was a difference among phases for all body regions evaluated (P < 0.05). All temperatures were higher in the ovulation phase. The rectal and vaginal temperatures measured by digital thermometer were lower during the diestrus period and increased during and after ovulation. The surface temperature of the vulva, measured by thermography, was higher from the estrus phase (4) to the ovulation and post-ovulation phases (5 and 6). The surface temperature of the muzzle was higher from the ovulation phase (5) to the post-ovulation phase (6), showing potential to detect ovulation. The thermography was efficient to detect small temperature variations during different phases of the estrous cycle, allowing the identification of different phases of the cycle in Santa Ines ewes.

Genetic diversity in oocyte donors used in in vitro bovine embryo production programs in Brazil / Diversidad genética en donadoras de ovocitos utilizadas en programas de producción de embriones bovinos in vitro en Brasil / Diversidade genética em doadoras de oócitos utilizadas em programas de produção de embriões bovinos in vitro no Brasil

Abstract Background: Current reproductive management of bovine elite populations involves the use of assisted reproductive technologies (ARTs), aiming to obtain the greatest genetic gain. However, inadequate use of ARTs may lead to loss of genetic diversity in the offspring. Objective: To assess the genetic diversity in elite female cattle populations used in commercial in vitro embryo production. Methods: Using genetic and ecological approaches for the study of populations based on microsatellite markers, we assessed the genetic diversity between and within populations of cows used in commercial in vitro embryo production programs in Brazil. Results: Endogamy within populations varied from zero to 9.1%, while heterozygosity between populations (FST) was <0.05 in the different population interactions. AMOVA showed 1% variation between populations, 8% between individuals and 91% within individuals. The dimensionality reduction method utilized indicated a lack of structure in the populations analyzed, identifying two main clusters in the three populations. Conclusions: Low genetic diversity between cow populations associated with commercial programs of in vitro embryo production in Brazil was evidenced. Variable levels of endogamy within the populations were observed. Approaches of population genetics as well as ecological diversity can be implemented to more thoroughly estimate genetic diversity in livestock populations.

Resumen Antecedentes: El actual manejo reproductivo en poblaciones de bovinos de élite incluye la utilización de tecnologías de reproducción asistida (ARTs) con el fin de obtener mayor ganancia genética. Sin embargo, el uso inadecuado de las ART puede llevar a la pérdida de diversidad genética en los descendientes. Objetivo: Evaluar la diversidad genética en poblaciones de vacas de élite utilizadas en la producción comercial de embriones bovinos in vitro. Métodos: Utilizando abordajes de la genética y ecología de poblaciones basados en marcadores microsatélites, evaluamos la diversidad genética entre y dentro de poblaciones de vacas participantes de programas comerciales de producción de embriones in vitro en Brasil. Resultados: La endogamia dentro de las poblaciones varió de cero a 9,1%, mientras que la heterocigosidad entre poblaciones (FST) fue <0,05 en las diferentes interacciones de la población. El AMOVA mostró variación del 1% entre poblaciones, 8% entre individuos y 91% dentro de individuos. El método de reducción de dimensionalidad utilizado indicó una falta de estructura en las poblaciones analizadas, identificando dos grupos principales en las tres poblaciones. Conclusiones: Se evidenció una baja diversidad genética entre las poblaciones de vacas asociadas a programas comerciales de producción de embriones in vitro en Brasil. Se evidenciaron niveles variables de endogamia entre las poblaciones. Abordajes de la genética poblacional, así como de diversidad ecológica pueden ser implementados para estimar de manera más amplia la diversidad genética en poblaciones animales de interés pecuario.

Resumo Antecedentes: O atual manejo reprodutivo das populações de elite em bovinos envolve o uso de tecnologias de reprodução assistida (ARTs), visando obter o maior ganho genético. No entanto, o uso inadequado de ARTs pode levar à perda de diversidade genética na prole. Objetivo: Avaliar a diversidade genética em populações de vacas de elite utilizadas na produção comercial de embriões bovinos in vitro. Métodos: Utilizando abordagens da genética e ecologia de populações baseadas em marcadores microssatélites, foi avaliada a diversidade genética entre e dentro das populações de vacas participantes de programas comercias de produção in vitro de embriões. Resultados: A endogamia dentro das populações variou de zero a 9,1%, enquanto a heterozigosidade entre populações (FST) foi <0,05 nas diferentes interações populacionais. AMOVA mostrou variação de 1% entre populações, 8% entre indivíduos e 91% dentro de indivíduos. O método de redução de dimensionalidade utilizado indicou uma falta de estrutura nas populações analisadas, identificando dois clusters principais nas três populações. Conclusões: Baixa diversidade genética entre populações de vacas associadas a programas de produção in vitro de embriões foi evidenciada. Níveis de endogamia variáveis dentro das populações foram observados. Abordagens da genética populacional assim como de diversidade ecológica podem ser implementadas na tentativa de estimar de maneira mais abrangente a diversidade genética em populações animais de interesse pecuário.