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The behavior of body condition, live weight and progesterone levels in the postpartum period during the resumption of ovarian activity was evaluated, based on racial type (Colombian Creole, Romney Marsh, Hampshire and Corriedale) and type of delivery (single and multiple) in 32 ovine females. The statistics were performed under a factorial structure model, using the SAS package. Among the results, it was found that body condition and weight begin to recover from day 21, with Creole and Romney Marsh starting earlier; the postpartum ovarian reactivation time was 31.8 ± 14.1 days on average, without showing significant differences within the evaluated groups. The type of delivery had a significant effect on the interval between first ovulation delivery (P <0.002), the interval between the first observed estrus (P <0.015), the interval between the first regular cycle (P <0.006) and the interval between onset of cyclicity (P <0.031), with females with a simple delivery having an earlier ovarian resumption. In the racial type * calving type interaction, no significant differences were found for the measured variables (P> 0.05). This study allowed to validate the effect of the type of parturition on the ovarian reactivation after childbirth, with the single parturition females recovering more quickly. [ABSTRACT FROM AUTHOR]

The sequence of phases (proestrus, estrus, metestrus, and diestrus) occurring between one heat period to another is known as the estrous or estrus cycle. In bats, studies determining the reproductive cycles have mainly been based on external traits, which implies that the reproduction classification is subject to the researcher's experience. In contrast, vaginal cytology analysis allows for a more reliable establishment of estrous cycle stages and reproductive conditions of the species. In this study, we used vaginal cytology analysis to determine the reproductive cycle of bat species captured between August 2018 and February 2020 in a peri-urban area in northern Cordillera Central. The reproductive condition of captured females was established externally, and those in condition active underwent vaginal cytology in the field. Subsequent slides analysis using Wright's stain was carried out in the laboratory. 73 individuals, including 38 females, of 13 species (Phyllostomidae and Vespertilinoidae) were captured. Of 23 females analyzed, 56.5% were in estrus, 21.7% in proestrus, 17.3% in diestrus, and 4.3% in metestrus. Vaginal cytology is a low-cost and low-risk methodology for the reproductive monitoring of bat populations, allowing us to understand the relationship between reproduction and environmental factors in human transformed environments. This study constitutes the first contribution to the reproductive biology of bats in an urban-rural system in the Antioquia department and is a reference on the frequency of the different estrous stages for the species Sturnira ludovici and Carollia perspicillata. [ABSTRACT FROM AUTHOR]

In Mexico, reproductive performance in beef cows is low and the use of synchronization of estrus and ovulation may help to improve it, thus the objective of this review was to describe the endocrine regulation the oestrus cycle and follicular dynamics in cattle, highlighting how these processes can be manipulated by using exogenous hormones. Moreover, we also present some data of pregnancy per artificial insemination (P/AI) with the different protocols of synchronization of estrus and ovulation reported in the literature. Reviews and original articles on the estrus cycle and follicular dynamics in cattle were compiled and PRSE data were obtained from papers published from 2000 to 2023. The range of P/AI was from of 23 to 76%, however despite this wide range, in treatments based on estradiol and GnRH around of 50% of the data of P/AI are between 45 and 55%. In progestin-based protocols, 50% of the P/AI observations were between 55 and 65%. Currently, there are three main protocols for synchronizing oestrus and ovulation that can be used, agree with the revised literature herein, to obtain P/AI between 45 and 65% in most cases with these protocols. [ABSTRACT FROM AUTHOR]

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Objetivo. Se evaluó la eficiencia en detección de calores, determinación de la duración y tipo de ciclo estral y concentración de progesterona en biotipos raciales ovinos, en el trópico alto. Materiales y Métodos. En 32 ovejas adultas, biotipo Criolla, Hampshire, Romney Marsh y Corriedale, durante el periodo posparto, se determinó la Eficiencia en Detección de Calores - EDC, tipo de ciclo: Corto – CC, Regular - CR y Largo - CL, Duración del Ciclo Estral – DCE y concentraciones de progesterona – CP4. Las CP4 se valoraron mediante técnica de ELISA. El análisis estadístico usó un modelo completamente al azar y medidas repetidas en el tiempo. Resultados. La EDC en promedio fue de 64.88%, presentándose 35.12% CC, 59.92% CR y 4.96% CL. El promedio de DCE regular fue de 16.9±0.89 días. El grupo Criollo presentó los mayores rangos de variación de la CP4, evidenciando cambios en su actividad esteroidogénica del cuerpo luteo semejante a lo observado con el grupo Hampshire. Entre el día 4 y 12 el grupo Romney Marsh presentó los menores CP4., siendo semejante al comportamiento del grupo Corriedale. Conclusiones. Las CP4 incrementan los días 2 a 6, manteniéndose altos y constantes entre los días 10 - 12, disminuyendo gradualmente hasta el día 18, evidenciando progresivamente una posible luteolisis funcional que conduce a una luteolisis estructural. Las CP4 pueden estar asociadas a fenómenos de adaptación de algunos grupos raciales, que afectan la eficiencia reproductiva que se observa es diferenciada entre ellos.

Copyright of Acta Veterinaria Brasilica is the property of Acta Veterinaria Brasilica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective. Efficiency in heat detection, determination of the duration and type of estrous cycle and progesterone concentration in sheep racial biotypes in the high tropics was evaluated. Materials and methods. In 32 adult ewes, biotype Criolla, Hampshire, Romney Marsh and Corriedale, during the postpartum period, Heat Detection Efficiency - EDC, cycle type: Short - CC, Regular - CR and Long - CL, Cycle Duration was determined. Oestrus – DCE and progesterone concentrations – CP4. CP4 were assessed by ELISA technique. Statistical analysis used a completely randomized model and repeated measures over time. Results. The average EDC was 64.88%, presenting 35.12% CC, 59.92% CR and 4.96% CL. The average of regular DCE was 16.9±0.89 days. The Criollo group presented the highest ranges of variation of CP4, showing changes in its steroidogenic activity of the corpus luteum similar to that observed with the Hampshire group. Between days 4 and 12, the Romney Marsh group presented the lowest CP4., being similar to the behavior of the Corriedale group. Conclusions. CP4 increases from days 2 to 6, remaining high and constant between days 10-12, gradually decreasing until day 18, progressively evidencing a possible functional luteolysis that leads to structural luteolysis. The CP4 may be associated with adaptation phenomena of some racial groups, which affect the reproductive efficiency that is observed to be differentiated between them. [ABSTRACT FROM AUTHOR]

Calf-raising is a stage in which optimal reproductive recovery of dams is required, and growth of calves. The objective of the study was to evaluate the use of strategic supplementation with silage shrubs, in the early weaning of BON x Zebu cattle. It was developed a research with 14 calves, of 5,2 months±1,05 of age and 127,57 ± 30,47 kg of weight, randomly distributed in a control treatment (To). In To treatment animals were in permanent lactation, and in the experimental treatment (Tex) animals were early weaned. In Tex treatment, the animals were assigned to a grazing system, with a mixed silage supplementation at a rate of 655 g/anymal/day. Body performance and weight gains in treatments were evaluated for 90 days. During this period measurements of consumption and weighing of the calves were made. The reproductive status of the dams was evaluated too. The data were analyzed with the statistical software R Project. There was no effect for the treatment, and for the treatment x month interaction on the body performance and weight gain of the calves, while Tex dams presented significant differences in weight and reproductive status. Therefore, early weaning favors the reproductive recovery of the dams. [ABSTRACT FROM AUTHOR]

El estudio tuvo como objetivo evaluar el efecto de la condición corporal (CC) sobre la actividad ovárica. La investigación se realizó en la granja genética Guayabal, perteneciente a la Universidad Agraria de La Habana -Mayabeque, Cuba-, con 57 vacas vacías de cuatro vaquerías. Los animales tuvieron condiciones similares de manejo y alimentación, y se dividieron en tres grupos según la escala de condición corporal para el ganado bovino destinado a la producción de leche: I: < 2,5; II: 2,5-3,5; III: > 3,5. Para determinar la actividad ovárica se realizó una inspección del estado general y se procedió a la exploración ginecológica. Con posterioridad, las vacas se dividieron en dos grupos: las que presentaban anestro y las que estaban ciclando. Se encontró un alto porcentaje de vacas en anestro con CC menor que 2,5. Asimismo, hubo un bajo porcentaje de vacas que estaban ciclando, en este grupo en las cuatro lecherías estudiadas. Se presentaron valores de anestro de 48,0; 51 y 0 % para los grupos I, II y III, respectivamente; mientras que en las diagnosticadas como hembras que estaban ciclando, después de la palpación rectal y que pudieron ser incorporadas a la reproducción fue del 16; 79 y 4 % para los grupos I, II y III, respectivamente. Se concluye que las hembras bovinas con condición corporal menor que 2,5 tuvieron ovarios con características compatibles a un anestro funcional; mientras que la mayor actividad ovárica se manifestó en las que poseían CC entre 2,5 y 3,5. Se recomienda analizar posibles soluciones para los animales de este rebaño, por las implicaciones en la producción láctea posterior.

O conhecimento das características reprodutivas das fêmeas bovinas é imprescindível que médicos veterinários possam exercer trabalhos inerentes a reprodução. Neste sentido, o conhecimento anatômico permite ao médico veterinário observar as estruturas presentes no trato reprodutor bovino e a funcionalidade de tais estruturas. Outro ponto a ser destacado é a compreensão dos eventos presentes no ciclo estral e como estes fatos influem no comportamento da fêmea. Além disso, a dinâmica folicular se faz parte indispensável do estudo, haja vista, que a fisiologia ovariana é a base da reprodução com influências na produção de hormônios e na gametogênese. Nesta perspectiva, o presente estudo visa elencar diversas peculiaridades presentes na reprodução bovina através de uma revisão de literatura.

El ciclo estral es el conjunto de acontecimientos fisiológicos que se producen en el ovario, a intervalos de tiempo cíclicos, como consecuencia de las variaciones en los niveles hormonales. Se han realizado varios trabajos tanto en ganado Bos taurus como en Bos indicus usando la ultrasonografía para evaluar los ciclos asociados a la reproducción tanto en vacas como en novillas bajo diferentes condiciones en donde se ha estado estableciendo las diversas diferencias entre estos dos tipos de ganado bovino. En el bovino, el ciclo estral tiene una duración media de 21 días considerándose normal un intervalo entre los 18 y 24 días. En el transcurso del ciclo, los ovarios sufren una serie de cambios que finalizan con la ovulación y la expulsión de un oocito capacitado para ser fertilizado por un espermatozoide y soportar el desarrollo embrionario temprano. Estos cambios están regulados por hormonas provenientes del hipotálamo, hipófisis, ovarios y útero. La presente revisión de literatura pretende ahondar en el tema a partir del acervo bibliográfico disponible.

Introduction: Direct vaginal cytology is a widely used method for the evaluation of the estrous cycle of laboratory rats, but the information about the procedures and interpretation of results is dispersed through literature, making its use difficult in investigations on reproduction. Objective: To propose a protocol for performing direct vaginal cytology of laboratory rats as well as for the interpretation of the results. Material and methods: The information obtained from literature and the experience of 10 years of investigation on reproduction in 250 female Wistar rats were combined following the established ethical principles. The procedures for obtaining samples by vaginal washing and by observation and analysis in humid state with light microscope equipped with digital camera were described. Results: The main types of cells present in the vaginal washing and the characteristics that allow us to identify each phase or transitional phases of the estrus cycle are described. Aspects to take into consideration in the interpretation of the results, which include the association between hormonal changes, the cares in the obtaining of the sample and the influence of environmental factors, are discussed. Representative images and figures are included to illustrate the text. Conclusions: The work consists of a study protocol of the estrus cycle of laboratory rats by direct vaginal cytology. It provides noninvasive, simple and cost-reducing procedures as well as essential knowledge for the interpretation of results which integrate a very useful guideline for experimental investigations on reproduction.

Copyright of Revista Habanera de Ciencias Médicas is the property of Universidad de Ciencias Medicas de La Habana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La crianza, es una etapa en la se requiere una óptima recuperación reproductiva de las vacas, y crecimiento de los terneros. El objetivo del estudio fue evaluar el uso de la suplementación estratégica con ensilaje de arbustivas forrajeras, en el destete precoz de ganado BON × Cebú. Se realizó un ensayo con 14 terneros, de 5,2 ± 1,05 meses de edad y 127,57 ± 30,47 kg de peso, distribuidos aleatoriamente en un tratamiento control (To), en lactancia permanente, y un tratamiento experimental (Tex) en destete precoz. En Tex, los animales fueron asignados a un sistema de pastoreo y suplementación con ensilaje mixto elaborado con Tithonia diversifolia, Gliricidia sepium, Cratylia argentea, y Crescentia cujete a razón de 655 g/animal/día. El desarrollo corporal y las ganancias de peso en los tratamientos, fueron evaluados durante 90 días. Se realizaron mediciones de consumo, peso de terneros y madres, así como del estado reproductivo de estas. Los datos fueron analizados en el software estadístico R Project. No hubo efecto del tratamiento, ni de la interacción tratamiento × mes en el desarrollo corporal y ganancias de peso de los terneros, mientras que, las madres de Tex presentaron diferencias significativas en el peso y estado reproductivo.

El vacuno criollo es un recurso potencial para mejorar la productividad en la zona altoandina del Perú; sin embargo, el cruce indiscriminado con razas mejoradas está llevando a la erosión de su material genético. Estudios de los procesos fisiológicos que rigen su ciclo reproductivo son fundamentales para la aplicación exitosa de biotecnologías reproductivas que aseguren su preservación, uso y posterior difusión. Con el fin de estudiar su dinámica folicular ovárica, se evaluaron 15 animales bajo condiciones de pastoreo en dos épocas del año (seca y lluviosa). El crecimiento folicular se evaluó mediante seguimiento ultrasonográfico, la actividad lútea mediante dosaje hormonal y se realizó el análisis proximal del pasto por época. La duración promedio del ciclo estral fue de 21,39 ± 1,17 días para la época de lluvias y 22,07 ± 1,04 días para la época seca, no observando diferencia estadística (p > 0,05). Se pudieron observar ciclos con 2 (16%), 3 (78%) y hasta 4 (6%) ondas foliculares. El diámetro máximo alcanzado del folículo ovulatorio fue de 17,11 ± 1,59 y 17,67 ± 1,21 mm en la época lluviosa y seca respectivamente. De las 49 ovulaciones estudiadas, 27 (55%) correspondieron al ovario derecho y 22 (45 %) al ovario izquierdo. No hubo diferencia (p > 0,05) en la tasa de crecimiento ni diámetro de los folículos por época. El diámetro máximo del cuerpo lúteo 20,87 ± 1,48 y 21,30 ± 1,86 mm con una tasa de crecimiento de 1,01 ± 0,16 y 1,0 ± 0,15 mm/día. Estos resultados reflejan el potencial del ganado criollo de mantener su ciclicidad aún en ambientes desfavorables.

Objetivo. Determinar la influencia de la condición corporal al parto (CCP) en el reinicio de la actividad ovárica (RAO) posparto de la vaca Holstein en la región andina de Ecuador. Materiales y métodos. Se trabajaron 30 vacas. Se determinaron el momento de aparición del folículo dominante (FD), de ovulación y de actividad luteal; la duración del ciclo estral, el volumen del cuerpo lúteo (CL) y las concentraciones de progesterona (P4) en suero sangíneo. Los estadígrafos descriptivos de las variables del RAO y sus indicadores se compararon según la CCP mediante una prueba de t-Student para muestras independientes. Se evaluó la asociación entre la CCP y el RAO posparto mediante un estudio caso control. Resultados. La duración del ciclo estral fue 23.10 días, el 46.67% de las vacas tuvo ciclos normales y el 53.33% ciclos anormales. El FD, la ovulación y la actividad luteal ocurrieron a los 16.63, 27.76 y 41.38 días posparto, respectivamente; antes (p

Este trabalho teve como objetivo descrever alguns conceitos importantes referentes à fisiologia reprodutiva, do controle farmacológico do ciclo estral, apresentando diferentes protocolos para a inseminação artificial em tempo fixo (IATF). A IATF se tornou uma das principais biotecnologias reprodutivas de importância econômica na produção de bovinos de maneira global. Os diferentes fármacos existentes atualmente no mercado permitem que se realize a sincronização do ciclo estral em novilhas com o intuito de maximizar os índices reprodutivos. Na literatura atual, inúmeros protocolos são citados capazes de induzir a ovulação para a IATF, fazendo necessário que se conheça de maneira ampla e aprofundada esses protocolos, afim de que seja escolhido o melhor para determinada situação e objetivo.

Creole cattle are a potential resource to improve productivity in the high Andean zone of Peru; however, indiscriminate crossing with improved breeds is leading to the erosion of their genetic material. Studies of the physiological processes that govern its reproductive cycle are essential for the successful application of reproductive biotechnologies that ensure their preservation, use and subsequent dissemination. In order to study the follicular dynamics of creole cattle, 15 animals were evaluated under grazing conditions in two seasons of the year (rainy and dry). Follicular growth was evaluated by ultrasonographic monitoring, luteal activity by hormonal dosing, and proximal analysis of grass was performed by season. The average length of the estrous cycle was 21.39 ± 1.17 days for the rainy season and 22.07 ± 1.04 days for the dry season, with no statistical difference (p > 0.05). Cycles with 2 (16%), 3 (78%) and 4 (6%) follicular waves was observed. The maximum diameter of the ovulatory follicle reached was 17.11 ± 1.79 and 17.67 ± 1.21mm in the rainy and dry seasons, respectively. Of the 49 ovulations studied, 27 (55%) corresponded to the right ovary and 22 (45%) to the left ovary. There was no difference (p > 0.05) in growth rate or follicle diameter by season. The maximum diameter of the corpus luteum was 20.87 ± 1. 48 and 21.30 ± 1.86 mm with a growth rate of 1.01 ± 0.16 and 1.0 ± 0.15 mm/day. These results reflect the potential of creole cattle to maintain their cyclicity even in unfavorable environments. [ABSTRACT FROM AUTHOR]

El objetivo del trabajo fue determinar el tamaño del folículo preovulatorio del cuerpo lúteo y los niveles de progesterona sanguínea en los días 6 y 12 post-ovulación en vaquillas de las razas Holstein, Brown Swiss y Criolla criadas en pastoreo en el Altiplano Ecuatoriano. Se determinó el tamaño del folículo preovulatorio, del cuerpo lúteo y los niveles sanguíneos de progesterona en los días 6 y 12 post-ovulación en nueve vaquillas de cada raza. La valoración de las estructuras ováricas se realizó mediante ultrasonografía. La concentración de progesterona sanguínea se determi-nó con el método de electroquimio-luminiscencia. Se estableció que el tamaño del folículo preovulatorio de las vaquillas Criolla fue más grande (14,6 ± 0,41 mm) que el de las Holstein (12,7 ± 0,47 mm) y Brown Swiss (12,7 ± 0,65 mm). La concentración de progesterona en los días 6 y 12 post-ovulación en las vaquillas Criolla (11,0 ±1,68 ng/ml y 18,4 ± 2,04 ng/ml, respectivamente) fue más elevada que el de las Holstein y Brown Swiss. Se observa-ron valores de asociación lineal altos y significativos (P < 0,05), entre el folículo preovulatorio; cuerpo lúteo y progesterona en las Holstein y Brown Swiss y se demostró que por cada milímetro de tamaño adicional sobre la media del Criolla del día 6, se generaría 1,67 ng/ml más de progesterona en las vaquillas Criolla (P < 0,05) que en las dos restantes. Se concluye que las vaquillas Criolla presentaron mayores niveles de progesterona en los días 6 y 12 post-ovulación en comparación con las razas Holstein y Brown Swiss, lo que generaría un mejor ambiente uterino y, por consiguiente, menores pérdidas embrionarias tempranas.

The objective of the study was to evaluate the effect of body condition (BC) on ovarian activity. The study was conducted in the Guayabal genetic farm, belonging to the Agricultural University of Havana --Mayabeque, Cuba--, with 57 empty cows from four dairy farms. The animals were under similar management and feeding conditions, and were divided into three groups according to the body condition scale for the cattle dedicated to milk production: I: < 2,5; II: 2,5-3,5; III: > 3,5. To determine the ovarian activity the general status was inspected and gynecological exploration was carried out. Afterwards, the cows were divided into two groups: those which showed anestrus and the ones that were cycling. A high percentage of anestrus cows with BC lower than 2,5 was found. Likewise, there was a low percentage of cows which were cycling in this group in the four studied dairy farms. Anestrus values of 48,0; 51 and 0 % were observed for groups I, II and III, respectively; while in the ones diagnosed as cows that were cycling after rectal palpation and could be incorporated to reproduction it was 16; 79 and 4 % for groups I, II and III, respectively. It is concluded that the cows with body condition lower than 2,5 had ovaries with characteristics compatible with functional anestrus; while the highest ovarian activity was shown in the cows that had BC between 2,5 and 3,5. To analyze possible solutions for the animals of this herd is recommended, due to the implications in subsequent milk production. [ABSTRACT FROM AUTHOR]

Introduction: infertility or inability to generate children is a problem that affects part of the population. Its treatment is usually done by hormone replacement, however, alternative therapies with the use of medicinal plants have been adopted. Objective: in view of the above, the present study aimed to evaluate the effect of Tribulus terrestris L. extract on the occurrence of the estrous cycle in ovariectomized and non ovariectomized mice. Methods: twentyeight female and adult Swiss mice were divided into four groups of 7 animals: group without ovariectomy and without supplementation or control, group with ovariectomy and no supplementation simulating infertility, group treated with Tribulus terrestris L. (10mg / kg) with ovariectomy and group treated with Tribulus terrestris L. (10mg / kg) without ovariectomy. The extracts were administered by way of gavage for 21 days. The estrous cycle was analyzed over this same time. Results: there was a significant increase in the proestrus phase of the estrous cycle in the ovariectomized group and supplemented when compared to the ovariectomized group and without supplementation. Conclusion: the significant increase in the occurrence of proestrus corresponds to a period of the estrous cycle related to the occurrence of ovulation. [ABSTRACT FROM AUTHOR]

Background: Corticosteroid responsive tremor syndrome is an immune-mediated disorder that primarily affects small dogs aged 1 to 5 years. It is manifested by generalized tremors of high frequency and low amplitude, with involvement of head, trunk and limbs. The diagnosis is based on history, clinical signs and laboratory tests to rule out other conditions, as well as on the response to corticosteroid treatment. The aim of the present study was to report a case of a female dog with corticosteroid responsive tremor syndrome that began after estrus. Case: A 1-year-old, undetermined dog, weighing 4.9 kg, was attended at the Veterinary Hospital of Uberaba, with generalized tremors that impaired her walking and feeding. The picture had an acute onset, there was no history of intoxication, trauma, but the animal had an organophosphate-based collar. The bitch was not castrated and had been in heat for a month. In the clinical evaluation, it was observed that besides the tremors, the dog had hypermetria and hyperthermia. Suspected adverse reaction to organophosphorus or encephalitis. The collar was removed from the animal. Hemogram, serum biochemistry, analysis and culture of cerebrospinal fluid and test for distemper were performed. The hemogram was leukopenia due to lymphopenia. No alterations were observed in serum biochemistry CSF culture and the distemper test were negative. The CSF analyte revealed pleocytosis with predominantly lymphocytes, density and glucose increased slightly. The diagnosis of encephalitis of inflammatory etiology was established. Treatment with prednisone and diazepam was performed. Clinical signs improved after seven days of therapy. Approximately one and a half years after the initial clinical picture, the animal presented recurrence of the tremors associated with estrus again. The same treatment was instituted and the dog underwent ovariohysterectomy. There was no relapse of the clinical picture. Discussion: Syndromes characterized by generalized tremors were initially described in white-coated dogs. Later, they were observed in dogs of other pelts and in cats. It currently receives different nomenclatures such as idiopathic tremor syndrome or corticosteroid responsive tremor syndrome. The animal history of the present case allowed to exclude the main differential diagnoses of tremors caused by medication, intoxication and hypomyelination. The clinical manifestations of hyperthermia, hypermetry and generalized tremors of high frequency and low amplitude were also described by other authors in cases of corticosteroid responsive tremor syndrome. The age and size of the animal is consistent with previous reports that observed a higher frequency in animals from 1 to 5 years of age of small breed. The absence of alterations in the tests that indicated an infectious process allowed the diagnosis of inflammatory disease and the rapid improvement of the clinical signs after treatment with prednisone allowed to establish the diagnosis of the syndrome of the responsive corticosteroid tremor. Recurrence of the clinical picture again after estrus suggests that the variation of the hormones estrogen and progesterone during this phase may influence neuronal excitability as well as stimulate an inflammatory reaction. Further studies are needed to clarify the pathophysiology of corticosteroid responsive tremor syndrome and to investigate this hypothesis of sex hormone involvement in inflammation. [ABSTRACT FROM AUTHOR]

The current paper characterizes the changes in morphology and vascularization of the corpus luteum of collared peccaries during the estrous cycle and correlates progesterone synthesis (P4). Twenty females were subjected to a treatment for estrus synchronization; an ear implant containing 1.5 mg of norgestomet was implanted on D0, whereas on D9 the peccaries received an IM injection of eCG 200UI and 50g of PGF2a. The animals were divided into four groups (G1, G2, G3 and G4) and euthanized on post-ovulation days 3, 12, 18 and 22. The ovaries were collected and the corpora lutea were measured and processed for histological and vascular density (Dv). Blood was collected for dosage of P4 serum. The morphology of the ovaries, the corpora lutea and P4 varied significantly during the estrous cycle (P

Objetivo. Evaluar la relación entre el diámetro del folículo ovulatorio (FO), el volumen del cuerpo lúteo (CL), los niveles séricos de progesterona (P4) con el éxito de la gestación. Materiales y métodos. En 19 vacas Holstein de 2 a 6 partos ubicadas en Bogotá, se evaluaron dos fases consecutivas a partir del día 40 postparto, la primera correspondió al ciclo estral y la segunda correspondió a la gestación temprana o repetición de celo. En cada fase se detectó el celo, se realizó ultrasonografía para evaluar el diámetro del FO, confirmar ovulación, y el volumen del CL los días 6, 9, 12 y 15; en estos días también se evaluó los niveles séricos de P4. En la segunda fase se realizó inseminación artificial (IA) y se diagnosticó la gestación 30 días post-IA. Resultados. El 47.36% de las vacas se diagnosticaron como gestantes y el 52.63% como no gestantes. Las gestantes presentaron diámetros de FO menores 17.85±2.39 mm al de las no gestantes (21.10±2.86 mm; p

Se evaluó el efecto de dos tratamientos, las granjas y la condición corporal en el tamaño del folículo y cuerpo lúteo. En uno de los tratamientos se aplicó D-Cloroprostenol (150 ug) y en el otro, D-Cloroprostenol (150 ug) y Ben-zoato de Estradiol (1mg). Se formaron dos grupos de 32 vacas Holstein cada uno, pertenecientes a las granjas Nero e Irquis, en Cuenca, Ecuador. Se tomó en cuenta la condición corporal (2,75-3,50), el número de partos fue de 1-6, las granjas (Irquis y Nero) y edad de los animales (3-10 años). Se usó ecografía a 0; 3 y 7 días, así para en el primer momento medir el cuerpo lúteo, luego el folículo dominante y la última el cuerpo lúteo. Se realizó un análisis de va-rianza factorial. No se encontraron diferencias significativas para el tamaño del folículo por efecto de ninguno de los factores ni la interacción, no así en el tamaño del cuerpo lúteo, donde se registraron diferencias s ignificativas (P < 0,05) para los tratamientos y para la granja. El valor fue superior en 0,33 cm en el tratamiento con Benzoato y de 0,36 cm en la granja Irquis respecto a Nero. La aplicación del tratamiento con Benzoato y el mejor manejo de la granja Irquis tuvieron influencia importante en la formación y desarrollo del cuerpo lúteo.

Objective This study evaluated the provision of two configuration of the Elevated Pluz-Maze (EPM) by analizing the exploratory behaviour of female Wistar rats in different phases of the estrous cycle in EPMs with different gradients of luminosity between the open and enclosed arms (O/E∆Lux).Methods Female Wistar rats were treated with Midazolam (MDZ, 1.0 mg.kg-1) and were tested for their exploratory behaviour in either the EPM 10 O/E∆Lux or EPM 96 O/E∆Lux.Results A multiple regression analysis indicated that the O/E∆Lux is negatively associated with the %Open arm entries and %Open arm time, suggesting that as O/E∆Lux increases, the open arm exploration decreases. The estrous cycle phase did not influence the open-arm exploration in either EPM. MDZ- induced anxiolysis was detected in 96 O/E∆Lux EPM in all phases of the EC.Discussion Results of this study suggest the importance of the O/E∆Lux to establish the arm preference in the EPM, and to preserve the predictive validity of the EPM.

The estrous cycle or interovulatory interval in the mare allows monitoring and selection of the most appropriate time for copulation or artificial insemination (AI). Estrous cycle is an interaction of hormones of the pineal gland, hypothalamus, pituitary, gonad and endometrium lasting 21 days. The pineal gland secretes melatonin during dark hours. In spring and summer, there is less melatonin secretion, and the hypothalamus secretes gonadotropin-releasing hormone (GnRH) to induce gonadotropins secretion: (FSH, follicle-stimulating hormone, and LH, luteinizing hormone) in the anterior pituitary and stimulates the ovulatory function. FSH promotes follicular growth and LH, follicular maturation and ovulation. Both stimulate the production of estradiol in the ovarian follicles. Estradiol causes estrus signs. After ovulation, the corpus luteum is formed and produces progesterone (P4) for gestation. P4 blocks the hypothalamus and reduces the secretion of GnRH, interrupting the estrous cycle. The hypothalamus produces oxytocin, which is stored in the neurohypophysis and acts on the endometrium, stimulating prostaglandin F2α secretion, to exert luteolysis, and the start of a new estrous cycle. In autumn and winter, ovulatory activity is interrupted. [ABSTRACT FROM AUTHOR]

Objectives. The aim of this study is to evaluate the relationship among ovulatory follicle (OF) size, corpus luteum (CL) volume, and progesterone (P4) serum levels with pregnancy success. Materials and methods. Nineteen Holstein cows located in Bogotá, Colombia with a history of 2 to 6 previous calving were used in the study. Following 40 day postpartum, two consecutive phases were evaluated as follows: 1) estrous cycle; 2) early pregnancy or return to estrus after Artificial Insemination (AI). Ultrasound exam was performed twice daily after first sign of estrus to evaluate OF diameter and CL volume, and serum P4 levels were evaluated on days 6, 9, 12 and 15 after ovulation. Cows were inseminated 12 hours post estrus signs and pregnancy was diagnosed 30 days post AI. Results. 47.36% of the cows were diagnosed as pregnant after AI. Pregnant cows had smaller OF diameters (17.85±2.39 mm) than non-pregnant females (21.10±2.86 mm) (p<0.05). Cows with smaller OF were more likely to become pregnant (OR=0.624, IC=95% (0.4-0.9) (p<0.05). There were non significant differences in the CL volume (p=0.10) and P4 serum values (p=0.39) between pregnant and no pregnant cows on days 6, 9, 12 and 15 post ovulation. Serum P4 levels were not correlated to CL size and reproductive status. Conclusions. This study shows that there was not significant difference in serum P4 levels and the CL volume when comparing pregnant with non-pregnant cows. A relationship was found between the OF diameter and the CL volume. Small OF diameter was a factor associated with early pregnancy. [ABSTRACT FROM AUTHOR]

The objective of the current study was to evaluate the preference of the consumption of four silage formulations, and their effect of the preferred silage on the ovarian activity of adult collared peccaries subjected to 35 days of ad libitum feed intake. In the first experiment, 12 adults non-pregnant Pecari tajacu females were used to which they were offered four silage mixtures, to measure the preference, through a 4 x 4 Latin square design. In the second experiment, five females were offered a diet with the most preferred silage, pumpkin, and corn, and five others consumed corn and squash. The blood progesterone levels of each female were measured weekly. The first experiment showed that the silage mixture with 55% of Brosimum alicastrum, 40% of Pennisetum purpureum and 5% of molasses was preferred (P <0.05). All the females in the group that consumed the diet with the preferred silage formulation and the corn-and-pumpkinbased diet showed one to two peaks of progesterone throughout the experiment. It is concluded that females submitted to diets with 40% silage of P. purpureum, 55% of B. alicastrum, 5% of molasses, corn, and pumpkin do not show alteration of the ovarian cyclicity during 35 days. [ABSTRACT FROM AUTHOR]

In wild animal species, the use of non-invasive and non-stressful procedures to determine hormone profiles, such as fecal steroid measurements, has considerably increased the comprehension of their reproductive physiology. Since there is limited information related to the reproductive hormone profiles of the two-toed sloth, Choloepus hoffmani, a study was conducted in captive specimens at the "Sloth Sanctuary" (Cahuita, Limón, Costa Rica), in order to determine: (i) the reliability of the fecal progesterone and estrogen extraction and its; quantification with an AIA-360 analyzer, (ii) assess blood parameters in this species and (iii) evaluate if there is a correlation between fecal and plasmatic steroids. The study was performed over a three-month period, from November, 2013 to January, 2014, with a total amount of 208 fecal samples collected from five sexually mature females weighing 6.32 kg in average. The average of the median concentrations of progesterone in feces of the five females was 124.21 ng/g, and 1 708.95 pg/g for estrogen. The average minimal and maximal values were 50.96 ng/g and 1 057.46 ng/g for progesterone and, 1 191.77 pg/g and 2 159.24 pg/g for estradiol. In plasma, progesterone median values were 1.26 ng/mL, showing a minimum of 0.32 ng/mL and 12.84 ng/mL as maximum values. The plasmatic estrogen levels were below the detection limit of the equipment (25 pg/mL). Although there was no strong statistical correlation between the fecal and plasmatic progesterone fluctuations, our data suggests that the plasmatic events are mostly reflected in feces two days afterwards. Also, the levels of progesterone were elevated during the first half of November and, subsequently, showed a successive and important reduction in all the females tested. Finally, our results demonstrated that fecal steroid extractions and their measurement in a AIA-360®, allowed the successful detection and represents an alternative non-invasive determination of hormone profiles in C. hoffmani. Rev. Biol. Trop. 66(1): 280-292. Epub 2018 March 01. [ABSTRACT FROM AUTHOR]

Collared peccaries (Peccary tajacu) are among the most hunted species in Latin America due the appreciation of their pelt and meat. In order to optimize breeding management of captive born collared peccaries in semiarid conditions, the objective was to describe and correlate the changes in the ovarian ultrasonographic pattern, hormonal profile, vulvar appearance, and vaginal cytology during the estrus cycle in this species. During 45 days, females (n=4) were subjected each three days to blood collection destined to hormonal dosage by enzyme immunoassay (EIA). In the same occasions, evaluation of external genitalia, ovarian ultrasonography and vaginal cytology were conducted. Results are presented as means and standard deviations. According to hormonal dosage, six estrous cycles were identified as lasting 21.0 ± 5.7 days, being on average 6 days for the estrogenic phase and 15 days for the progesterone phase. Estrogen presented mean peak values of 55.6 ± 20.5 pg/mL. During the luteal phase, the high values for progesterone were 35.3 ± 4.4 ng/mL. The presence of vaginal mucus, a reddish vaginal mucosa and the separation of the vulvar lips were verified in all animals during the estrogenic peak. Through ultrasonography, ovarian follicles measuring 0.2±0.1 cm were visualized during the estrogen peak. Corpora lutea presented hyperechoic regions measuring 0.4±0.2 cm identified during luteal phase. No significant differences (P>0.05) between proportions of vaginal epithelial cells were identified when comparing estrogenic and progesterone phases. In conclusion, female collared peccaries, captive born in semiarid conditions, have an estral cycle that lasts 21.0±5.7 days, with estrous signs characterized by vulvar lips edema and hyperemic vaginal mucosa, coinciding with developed follicles and high estrogen levels.

The aim of this paper was to determine the size of the pre-ovulation follicle in the corpus luteum, and in blood progesterone on the sixth and twelfth days after ovulation, in Holstein, Brown, Swiss and Criolla breeds grazing on Ecuadoran Highlands. The size of the pre ovulation follicle and corpus luteum, and the levels of blood progesterone were determined on days sixth and twelfth, in nine heifers from each breed. Assessment of ovarian structures was made by ultrasound scanning. The concentration of blood progesterone was determined by electrochemiluminescence. The pre ovulation follicle in Criolla heifers was larger (14.6 ± 0.41 mm) than in Holstein (12.7 ±0.47 mm), and in Brown Swiss (12.7 ± 0.65 mm). Progesterone concentration on days six and twelve after ovulation of Criolla heifers (11.0 ± 1.68 ng/ml, and 18.4 ± 2.04 ng/ml, respectively) was higher than for Holstein and Brown Swiss. The linear association values were high and significant (P < 0.05), in the pre ovulation follicle, corpus luteum and progesterone, in Holstein and Brown Swiss. It was demonstrated that for every additional millimeter above the Criolla mean on the sixth day, 1.67 ng/ml more of progesterone was generated in Criolla heifers (P < 0.05) than in the rest. It was concluded that the Criolla heifers had higher progesterone levels than Holstein and Brown Swiss on the sixth and twelfth days, thus producing better conditions in the uterus and lower early embryo losses. [ABSTRACT FROM AUTHOR]

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Con el objetivo de estimar parámetros reproductivos de referencia en yeguas criollas colombianas (CC), se emplearon 30 yeguas a las que se les realizó seguimiento de dos ciclos estrales (CE). La duración del CE fue 21,5 ± 1,8 días (promedio ± DE), la cual fue similar en el 40% de las yeguas en los dos CE, en el 60% restante la duración en-tre los dos CE tuvo una diferencia entre 1 a 7 días. La tasa de crecimiento diario del folículo dominante (FD) fue de 1,62 ± 0,4 mm y la del folículo subordinado (FS) de 0,65 ± 0,4 mm. La desviación folicular se presentó el día 17,2 ± 3,0 del CE. El tamaño máximo del FD fue 44,3 ± 4,8 mm. En el 63% de los CE el FD se ubicó en el ovario derecho y en el 37% en el izquierdo. En el 85% de los CE ocurrió primero el edema uterino y después los signos de celo. El grado de edema disminuyó antes de la ovulación en 86,6% de los CE. La duración del estro fue 5,9 ± 1,8 días. Hasta 48 horas poso-vulación se presentaron signos de celo en el 73,3% de los CE y en el 26,6% ningún signo de celo. Según los valores obtenidos, aunque los parámetros reproductivos son similares a los descritos para otras razas de equinos en países diferentes a Colombia, hay algunas diferencias que deben tenerse en cuenta en las prácticas clínicas de rutina en la reproducción de las yeguas CC.

Plasma concentration of progesterone and 17β-estradiol of black-rumped agouti (Dasyprocta prymnolopha) during the estrous cycle. The agouti is a game animal that have been raised in captivity for conservation and sustainability purposes. However, the management of wild animals in an intensive breeding system requires an assertive knowledge of its reproductive parameters, one of the most important features for production improvement. Besides, little information is available regarding changes in reproductive hormone profiles in agouti. The objective of this study was to evaluate the hormonal profile of progesterone and 17β-estradiol during the estrous cycle of the agouti (Dasyprocta prymnolopha). The hormones were analyzed by radioimmunoassay. Blood samples were collected without sedation twice a week. The concentrations of progesterone were as follows: proestrus 0.78+0.39ng/ml, estrus 2.83+2.34ng/ml, metestrus 1.49+1.24ng/ml, diestrus 3.71+1.48ng/ml. In the estrous phase, an increase in the progesterone level was observed during a period of 24h. The average 17 β-estradiol levels were as follows: proestrus 2 030.98+961.00pg/ml, estrus 1 910.56+650.54pg/ml, metestrus 1 724.83+767.28pg/ml, diestrus 1 939.94+725.29pg/ml. The current results suggest that the progesterone plasma concentration during the estrous cycle in the agouti has a similar increasing, stabilizing and decreasing pattern, as in domestic mammals. Agoutis have two phases of follicular development, as two periods of 17β-estradiol peaks were observed, the first one in the metestrus and the second during the proestrus. Spontaneous ovulation seems to occur after the progesterone peak, possibly indicating that this hormone is associated with the ovulatory process. A more detailed investigation is needed for better understanding of how progesterone influences ovulation. Studies on the involvement of progesterone in follicular rupture can be carried out, using steroid biosynthesis inhibitors and observing the effect of this hormone on ovarian activity of proteolytic enzymes in the follicular wall. Rev. Biol. Trop. 59 (1): 29-35. Epub 2011 March 01.El conocimiento de los procesos reproductivos de especies de importancia económica local son indispensables para apoyar su producción en cautiverio y garantizar su manejo sostenible. El objetivo del presente trabajo fue evaluar los niveles hormonales de progesterona y 17β-estradiol durante el ciclo estral en agutí (Dasyprocta prymnolopha). La recolección de sangre se realizó dos veces por semana, sin sedación. Las hormonas fueron analizadas por radioinmunoanálisis. Los niveles de progesterona fueron los siguientes: proestro 0.78+0.39ng/ml, estro 2.83+2.34ng/ml, metaestro 1.49+1.24ng/ml y diestro 3.71+1.48ng/ml. En el estro se observó un aumento de los niveles de progesterona durante un periodo de 24h. Los niveles de 17 β-estradiol fueron los siguientes: proestro 2 030.98+961.00pg/ml, estro 1 910.56+650.54pg/ml, metaesto 1 724.83+767.28pg/ml y diestro 1 939.94+725.29pg/ ml. Los resultados encontrados sugieren que los niveles plasmáticos de progesterona durante el ciclo estral en agutí siguen un patrón de aumento, estabilización y diminución, tal como en los mamíferos domésticos. Agutí tienen dos etapas de desarrollo folicular, puesto que se observaron dos altos valores de 17β-estradiol, el primero en el metaestro y el segundo durante el proestro. La ovulación espontánea ocurre posiblemente después del aumento de la progesterona, indicando que esta hormona posiblemente está asociada con el proceso ovulatorio. Es necesario desarrollar un estudio más detallado para mejorar la comprensión del papel de la progesterona en la ovulación. Algunos estudios de la participación de la progesterona en la ruptura folicular se pueden realizar utilizando inhibidores de la biosíntesis de esteroides y observar el efecto de esta hormona sobre la actividad de las enzimas proteolíticas en la pared folicular.