Abstract Follicular dynamics in dairy sheep is poorly understood. This study assessed the follicular dynamics of dairy sheep within and out of the breeding season by observing the effect of two progesterone concentrations (60 and 120 mg) used in vaginal pessaries in pre-synchronization. The experiment was conducted in April/May and October/November using 40 healthy multiparous dairy ewes predominantly of the Lacaune breed, which underwent daily transrectal ultrasound examinations. The number of ovulations (1.35 vs 1.05), ovulatory follicle diameter (mm) (5.97 vs 5.05), length of the luteal phase (11 vs 9.14 days), and length of the estrous cycle (16.83 vs 16.6 days) were assessed within and out of the breeding season, respectively. The sheep out of the breeding season did not present a corpus luteum at the time of insertion of the vaginal pessary, characterizing anestrus. The ovulatory follicle had a larger diameter in the breeding season even with the shorter length of the follicular phase, suggesting higher viability and quality of the ovulated oocyte. The application of exogenous progesterone extends the luteal phase in the breeding season (11 vs 9.14 days). The anestrus observed out of season suggests the need for a higher progesterone concentration in reproductive protocols. Therefore, breeding protocols can be adapted for different seasons, suggesting the use of vaginal pessaries with a higher progesterone concentration (120 mg) out of the breeding season. The data allowed the characterization of follicular dynamics in dairy sheep, demonstrating their differences in each season based on the use of different progesterone doses in pre-synchronization. understood 60 (6 12 mg presynchronization. presynchronization pre synchronization. synchronization pre-synchronization AprilMay April May OctoberNovember October November 4 breed examinations 1.35 135 1 35 (1.3 1.05, 105 1.05 , 05 1.05) mm (mm 5.97 597 5 97 (5.9 5.05, 505 5.05 5.05) 11 (1 914 9 14 9.1 days, days 16.83 1683 16 83 (16.8 166 6 16. respectively pessary oocyte days. . Therefore seasons (12 ( 1.3 13 3 (1. 10 1.0 0 5.9 59 (5. 50 5.0 91 9. 16.8 168 8 (16. 1. 5. (5 (16

Resumo A dinâmica folicular em ovelhas leiteiras é pouco compreendida. Neste trabalho foi avaliado a dinâmica folicular de ovelhas leiteiras, dentro e fora da estação reprodutiva observando o efeito de duas concentrações de progesterona (60 e 120mg) utilizadas em pessários vaginais na pré-sincronização. O experimento foi realizado nos meses de abril/maio e outubro/novembro, utilizando 40 ovelhas multíparas leiteiras hígidas, predominantemente da raça Lacaune, que foram submetidas a exames ultrassonográficos diários por via transretal. Na estação reprodutiva foram avaliados o número de ovulações (1,35 vs 1,05), o diâmetro(mm) do folículo ovulatório (5,97 vs 5,05), a duração da fase lútea (11 vs 9,14 dias) e a duração do ciclo estral (16,83 vs 16,6 dias) dentro da estação em comparação com fora da estação reprodutiva respectivamente. Fora da estação as ovelhas não apresentaram corpo lúteo no momento da inserção do pessário vaginal, caracterizando anestro. Mesmo com menor duração da fase folicular, o folículo ovulatório apresentou maior diâmetro na estação reprodutiva, sugerindo maior viabilidade e qualidade do oócito ovulado. A aplicação de progesterona exógena amplia a fase lútea na estação reprodutiva (11 vs 9,14 dias). O anestro observado fora de época sugere a necessidade de maior concentração de progesterona nos protocolos reprodutivos. Desta forma, é possível adaptar protocolos reprodutivos para diferentes épocas, sugerindo o uso de pessários vaginais com maior concentração de progesterona (120 mg) fora da estação reprodutiva. Os dados obtidos permitiram caracterizar a dinâmica folicular em ovelhas leiteiras, demonstrando suas diferenças em cada estação a partir do uso de diferentes doses de progesterona na pré-sincronização compreendida 60 (6 120mg mg présincronização. présincronização pré sincronização. sincronização abrilmaio abril maio outubronovembro outubro novembro outubro/novembro 4 hígidas Lacaune transretal 1,35 135 1 35 (1,3 1,05, 105 1,05 , 05 1,05) diâmetromm mm diâmetro(mm 5,97 597 5 97 (5,9 5,05, 505 5,05 5,05) 11 (1 914 9 14 9,1 dias 16,83 1683 16 83 (16,8 166 6 16, respectivamente vaginal ovulado dias. . forma épocas 120 (12 ( 1,3 13 3 (1, 10 1,0 0 5,9 59 (5, 50 5,0 91 9, 16,8 168 8 (16, 12 1, 5, (5 (16

Abstract This study aimed to validate the methodology of immunochemiluminescence (CLIA) using an enzyme-linked immunosorbent assay (ELISA) to determine serum progesterone (P4) concentrations in non-pregnant multiparous dairy (12 Holstein cows) and beef (18 Nellore cows) cows during the estrous cycle. Cows with corpus luteum were chosen for estrus and ovulation synchronization by administering 500 mcg of cloprostenol. After luteolytic application, the animals were subjected to ovarian ultrasonography (US) daily to verify ovulation (day zero of the cycle) and two blood samples were collected for P4 determination using CLIA and ELISA. Samples were centrifuged to obtain serum and frozen at -20 °C for later measurement. ELISA and CLIA values were compared using the paired t-test, regression, analysis of variance, and coefficient of determination (R2) to verify sensitivity and linear correspondence. The P4 concentration determined by both methodologies showed a similar profile; the P4 profiles were higher in beef cattle than in dairy cattle. The correspondence between the methodologies resulted in a high quotient for R2 the P4 profiles. It was concluded that CLIA can be used for hormonal determinations of bovine serum P4. CLIA showed a high linear correspondence with ELISA values and can thus aid reproductive biotechnologies for hormone determination. (CLIA enzymelinked enzyme linked (ELISA P (P4 nonpregnant non pregnant 12 (1 18 cycle 50 cloprostenol application US (US day 20 -2 C measurement ttest, ttest t test, test t-test regression variance R (R2 profile (P 1 ( 5 2 - (R

Resumo O objetivo do estudo foi validar a metodologia da imunoquimioluminescência (CLIA) através da imunoabsorção enzimática (ELISA), determinando a concentração sérica de progesterona em vacas de leite e de corte, durante o ciclo estral. Foram empregadas 30 vacas multíparas não-prenhes (12 da raça Holandesa Preta e Branca e 18 Nelore). Vacas com corpo luteo foram escolhidas com vistas à sincronização do estro e da ovulação, mediante aplicação de 500 mcg de cloprostenol (im). Após a aplicação do luteolitico, os animais foram diariamente submetidos a exames de ultrasssonagrafia (US) ovariana para verificação da ovulação (=dia 01 do ciclo), bem como eram colhidas 02 amostras de sangue para a determinação da P4 pela CLIA e ELISA. As amostras eram centrifugadas para a obtenção do soro, e congeladas a -20 graus para posterior dosagem. Os valores de ELISA e CLIA foram comparados entre si mediante teste t pareado, regressão, ANOVA e coefficiente de determinação (R2), visando a verificação da sensibilidade e correspondência linear. A concentração de P4 originou perfis similares entre as duas metodologias; os perfis de P4 foram mais elevados em bovinos de corte, que nos de leite. A correspondência entre as metodologias resultou em elevado quociente de R2 nos perfis de P4. Concluiu-se que a CLIA pode ser empregada nas determinações hormonais da P4 serica bovina; a CLIA mostrou elevada correspondência linear com os valores da ELISA; a CLIA pode auxiliar as biotecnicas da reprodução nas determinações hormonais. (CLIA ELISA, , (ELISA) corte estral 3 nãoprenhes não prenhes 12 (1 1 Nelore. Nelore . Nelore) 50 im. im (im) luteolitico US (US =dia dia 0 ciclo, ciclo) P soro 20 -2 dosagem pareado regressão R2, R (R2) Concluiuse Concluiu se bovina (ELISA ( 5 (im 2 - (R2 (R

Resumen En México, la eficiencia reproductiva de las vacas en los sistemas de producción de becerro es baja y el uso de esquemas de sincronización del estro y la ovulación puede contribuir a mejorarla. El objetivo de esta revisión fue describir la regulación endocrina del ciclo estral y la dinámica folicular en los bovinos, resaltando cómo, a través del uso de hormonas exógenas se pueden manipular estos procesos para implementar los diferentes protocolos de sincronización del estro y la ovulación. Además, se presentan resultados de tasa de preñez a estro sincronizado (TPES) con los diferentes protocolos de sincronización de estro y ovulación que se reportan en la bibliografía. Se recopilaron revisiones y artículos originales sobre temas de ciclo estral y desarrollo folicular en bovinos y se obtuvieron datos de TPES de artículos científicos publicados entre 2000 y 2023. La TPES reportada oscila entre 23 hasta 76%, sin embargo, aunque el rango es amplio, en protocolos basados en estradiol y GnRH alrededor del 50% de los datos de TPES colectados están entre 45 y 55%. En protocolos basados en progesterona el 50% de los datos reportan TPES de entre 55 y 65%. En la actualidad, existen tres principales protocolos de sincronización de estro y ovulación con los que, según la bibliografía revisada, se puede obtener TPES de entre 45 y 65% en la mayoría de las ocasiones.

Abstract In Mexico, reproductive efficiency of cows in calf production systems is low and the use of estrus and ovulation synchronization schemes can contribute to improve it. The objective of this review was to describe the endocrine regulation of the estrous cycle and follicular dynamics in cattle, highlighting how, using exogenous hormones, and these processes can be manipulated to implement different estrous and ovulation synchronization protocols. In addition, results of pregnancy rate at synchronized estrus (PRSE) with the different estrous and ovulation synchronization protocols reported in the literature are presented. Reviews and original articles on topics of estrous cycle and follicular development in cattle were collected and PRSE data were obtained from scientific articles published between 2000 and 2023. The reported PRSE ranges from 23 to 76 %, however, although the range is wide, in estradiol and GnRH based protocols about 50 % of the PRSE data collected are between 45 and 55 %. In progesterone-based protocols, 50 % of the data report PRSE between 55 and 65 %. Currently, there are three main estrous and ovulation synchronization protocols with which, according to the literature reviewed, PRSE between 45 and 65 % can be obtained in most occasions.

Abstract The reproductive response of nulliparous-anovulatory Dorper ewes exposed to rams treated with selenium (Se) plus vitamin E (Vit. E) was evaluated. A first of rams was treated (GT; n = 5) with 1 mg of Se plus 70 IU of Vit. E x every 10 kg of LW via IM, and a second group, control (GC; n = 5) with 1 mL of saline solution, both treatments were applied every 7 days x 28 days. At the end of the treatments, the groups of rams were placed in contact with two groups of females (n = 17 each), and the appetitive (CSA) and consummatory (CSC) sexual behavior of the rams was recorded. The reproductive response of ewes exposed to males was similar (P > 0.05) in both treatments. Treatment with Se plus Vit. E did not stimulate the sexual behavior of the rams and therefore the reproductive response of the ewes was not enhanced.

Resumen Se evaluó la respuesta reproductiva de ovejas Dorper nulíparas-anovulatorias expuestas a carneros tratados con selenio (Se) más vitamina E (Vit. E). Un primer de carneros, fue tratado (GT; n = 5) con 1 mg de Se más 70 UI de Vit. E x cada 10 kg de PV vía IM, y un segundo grupo, control (GC; n = 5) con 1 mL de solución salina, ambos tratamientos fueron aplicados cada 7 días x 28 días. Al final de los tratamientos, los grupos de carneros fueron puestos en contacto con dos grupos de hembras (n = 17 c/u), y se registró el comportamiento sexual apetitivo (CSA) y consumatorio (CSC) de los carneros. La respuesta reproductiva de las ovejas expuestas a los machos fue similar (P > 0.05) en ambos tratamientos. El tratamiento con Se más Vit. E no estimuló el comportamiento sexual de los carneros y, por consiguiente, no se mejoró la respuesta reproductiva de las ovejas.

Resumen Introducción. Alrededor de 3700 millones menores de 50 años con infección por VHS-1 y 491 millones de personas de 15 a 49 años cursan con infección por VHS-2 en el mundo; sus síntomas, vesículas o ulceras dolorosas reaparecen periódicamente. El tratamiento convencional disminuyó su efectividad en cepas resistentes e inmunodeprimidos. Alternativas terapéuticas con extractos de plantas medicinales y potencial antiviral, como Opuntia soehrensii Brito conocida como “ayrampù” en Bolivia, utiliza infusión de sus semillas como analgésico, antidiabético, hipotensor y febrífugo. En vapores por inhalación para afecciones respiratorias; como tintura tópica en lesiones dérmicas de viruela, sarampión y herpes labial. Objetivo. Evaluar la seguridad preclínica de un gel que contiene el extracto hidro-alcohólico de semillas de Opuntia soehrensii en diferentes dosis, aplicado en la mucosa vaginal de ratas Sprague Dawley. Material y métodos. Se ejecutaron protocolos de toxicidad aguda y subaguda para evaluar la respuesta sistémica, a través de marcadores bioquímicos y de comportamiento, y la respuesta local en mucosa vaginal, mediante estudios histopatológicos, en grupos de animales a los que se aplicó el gel con diferentes concentraciones del extracto de Opuntia soehrensii, comparados con un grupo control y otro que recibió solo el vehículo. Resultados. Se encontró que los indicadores sistémicos de comportamiento y ganancia de peso no mostraron diferencias entre grupos. Los indicadores hematológicos y bioquímicos mostraron resultados fisiológicamente esperados y sin cambios en los grupos de estudio. La citología expuso conservación del fenotipo celular para las fases del ciclo estral en todos los grupos. Los indicadores histológicos de reacción local e integridad celular se distribuyeron de igual manera en los todos los grupos. Conclusión. La aplicación de un gel de Opuntia soehrensii no muestra niveles apreciables de toxicidad local y sistémica, lo que permite recomendar la iniciación de estudios de aplicación clínica.

Abstract Introduction. Around 3.7 billion people under 50 years of age are infected with HSV-1 and 491 million people between the ages of 15 and 49 are infected with HSV-2 in the world; his symptoms, vesicles or painful ulcers recur periodically. Conventional treatment decreased its effectiveness in resistant and immunosuppressed strains. Therapeutic alternatives with extracts of medicinal plants and antiviral potential, such as Opuntia soehrensii Brito known as "ayrampù" in Bolivia, uses infusion of its seeds as an analgesic, antidiabetic, hypotensive and febrifuge. In vapors by inhalation for respiratory conditions; as a topical tincture in skin lesions of smallpox, measles and cold sores. Objectives . To evaluate the preclinical safety of a gel containing the hydroalcoholic extract of Opuntia soehrensii seeds in different doses, applied to the vaginal mucosa of Sprague Dawley rats. Material and Methods. Acute and sub-acute toxicity protocols were carried out to evaluate local response in the vaginal mucosa, through histo pathological studies, and systemic responses, through biochemical and behavioral markers, in groups of animals to which the gel with different concentrations of the extract of Opuntia soehrensii was applied, compared with a control group and another that received only the vehicle. Results. It was found that the histological indicators of local reaction and cell integrity were equally distributed in all groups. Cytology showed conservation of the cell phenotype for the phases of the estrous cycle in all groups. The systemic indicators of behavior and weight gain did not show differences between groups. Hematological and biochemical indicators showed results ranged in physiologic parameters, without changes in the study groups. Conclusion. The application of a gel from Opuntia soehrensii does not show appreciable levels of local and systemic toxicity, which makes it possible to recommend the initiation of clinical application studies.

SUMMARY: Estradiol and progesterone receptors play an essential role in the changes occurring in the uterus during the estrus cycle in dogs (Canis lupus familiaris). In order to investigate the potential effect of progestational agent medroxyprogesterone acetate (MPA) when is used during anestrus on the expression of estradiol receptors [ER], progesterone receptors [PR] and nuclear protein Ki67, we evaluated uterine tissue immunohistochemically. Uteri were grouped as nulliparous (control, n=11), multiparous (n=11) and treated with MPA (n=11; nulliparous with two treatments; 5mg/kg; i.m.). The amount and location of PR, ER and Ki67 were studied on the epithelial surface, apical and basal regions of the endometrium and myometrium using immunohistochemical techniques with a spectral confocal microscope and analyzed by ANOVA. Differences in ER were observed between the multiparous and MPA-treated groups in the apical region of the endometrium (p=0.0022). Differences in cell proliferation were detected between the nulliparous and multiparous groups (p=0.0037) and nulliparous and MPA-treated groups (p=0.0003) in the basal region of the endometrium. In conclusion, two doses of MPA (5mg/kg; i.m.) do not have a significant effect on the expression of ER and PR; however, they inhibit cell proliferation in the basal region of the endometrium, which includes the stroma, subepithelial cell layer, compact layer, and spongy layer. The clinical and long-term effect of this treatment should be evaluated in subsequent studies.

RESUMEN: Los receptores de estradiol y progesterona juegan un rol fundamental en los cambios que se producen en el útero durante el ciclo estral de las perras (Canis lupus familiaris). El objetivo de este estudio fue evaluar las expresiones de ER-a y PR en el útero y la proliferación de células endometriales detectando la expresión nuclear de la proteína Ki67 en perras expuestas a la progestina sintética MPA y compararlas con perras nulíparas y multíparas expuestas a progesterona luteal. Úteros fueron agrupados como nulíparas (control, n=11), multíparas (n=11) y tratadas con MPA (n=11; nulíparas con dos tratamientos; 5 mg/kg; i.m.). La expresión de PR, ER-a y Ki67 fue evaluada en la regiones apicales y basales del endometrio y miometrio con un microscopio confocal espectral. Se observó diferencias en ER-a entre los grupos multíparas y tratados con MPA en la región apical del endometrio (p=0,0022). Se detectaron diferencias en la proliferación celular entre los grupos de nulíparas y multíparas (p=0,0037) y los grupos de nulíparas y tratados con MPA (p=0,0003) en la región basal del endometrio. En conclusión, dos dosis de MPA (5mg/kg; i.m.) no tienen un efecto significativo sobre la expresión de ER y PR; sin embargo, inhiben la proliferación celular en la región basal del endometrio, el cual incluye a estroma, capa de células subepiteliales, estratos compacto y esponjoso. El efecto clínico a largo plazo de este tratamiento debe ser evaluado en estudios posteriores.

Abstract Spix's yellow-toothed cavies are rodents displaying high biological and farming potential. Knowledge of cavy reproductive aspects is paramount for satisfactory breeding. This study aimed to determine the gestation length and characterize the reproductive cycle phases of Spix's yellow-toothed cavies, also investigating potential male effects on these processes. The investigated animals were categorized into three groups: Gestational follow-up (G1), with a 5:1 female-to-male enclosure ratio; estrous cycle (G2), with a 5:1 female-to-male ratio with a male confined to a cage; and G3, consisting of five females and no male. Daily colpocytological examinations were performed, with the presence of spermatozoa on the microscopy slides indicative of copulation. G1 females were separated from the male immediately after copulation, with this being considered day "zero" of the pregnancy. G2 and G3 females were evaluated for two complete estrous cycles and qualitatively assessed through vaginal smears. The gestation length of the Spix's yellow-toothed cavies averaged 59 ± 2.24 days, with a continuous polyestrous cycle lasting 14.8 ± 0.73 days in G2 and 14.6 ± 0.75 days in G3. The proestrus phase was characterized by the dominance of parabasal cells, dyes, bacteria, and leukocytes; the estrus phase, by superficial cells with the predominance of anucleate cells with and without the presence of bacteria; the metestrus phase, by parabasal cells and numerous genuine cells, neutrophils, and bacteria; and the diestrus phase, mainly by basal, parabasal, and mutant cells, as well as high amounts of vaginal mucus, neutrophils, and bacteria. The presence of a male cavy significantly influenced diestrus duration, prolonging this phase, which is potentially attributed to female progesterone production effects. Spixs Spix s yellowtoothed yellow toothed breeding processes groups followup follow up G1, G , (G1) 51 5 1 5: femaletomale G2, (G2) cage performed copulation zero "zero pregnancy smears 224 2 24 2.2 148 14 8 14. 073 0 73 0.7 146 6 075 75 dyes bacteria leukocytes neutrophils basal mucus duration (G1 (G2 22 2. 07 7 0. (G

Resumo O preá é um roedor com elevado potencial biológico e zootécnico a ser explorado, sendo o conhecimento sobre os aspectos reprodutivos fundamentais para que sua criação seja satisfatória. Objetivou-se determinar a duração da gestação em preás, e a caracterização das fases do ciclo reprodutivo, verificando, se existe influência da presença do macho neste processo. Os animais foram separados em três grupos: Acompanhamento gestacional (G1), 5:1, proporção de fêmea e macho no box; Ciclo estral, 5:1, com o macho preso em gaiola (G2) e cinco fêmeas em outro box sem o macho (G3). O exame colpocitológico ocorreu diariamente, identificado o espermatozoide na lâmina como cópula. As fêmeas do G1 foram separadas assim que copulavam e contadas como dia “zero” da gestação. As fêmeas do G2 e G3 foram avaliadas ao longo de dois ciclos estrais completos, avaliados qualitativamente pelo o esfregaço vaginal. O período de gestação em preás foi de 59±2,24 dias, com um ciclo poliéstrico contínuo, com duração de 14,8±0,73 dias no G2 e 14,6±0,75 dias no G3. O proestro caracterizou-se pelo predomínio de células parabasais, intermediárias, bactérias e leucócitos; o estro, células superficiais, com predomínio das anucleadas com presença ou não de bactérias; metaestro, células parabasais e grande quantidade de células intermediárias, neutrófilos e bactérias; diestro, predomínio de células basais, parabasais e intermediárias e grande quantidade de muco vaginal, neutrófilos e bactérias. A presença do macho influenciou significativamente a duração do diestro, tornando-se mais longa, fato que pode estar atrelado a influência sobre a produção de progesterona na fêmea. explorado satisfatória Objetivouse Objetivou reprodutivo verificando processo grupos G1, G , (G1) 51, 51 5 1, 1 5:1 estral (G2 . (G3) diariamente cópula zero “zero completos vaginal 59224 59 2 24 59±2,2 contínuo 148073 14 8 0 73 14,8±0,7 146075 6 75 14,6±0,7 caracterizouse caracterizou leucócitos estro superficiais metaestro diestro basais tornandose tornando longa (G1 5: (G (G3 5922 59±2, 14807 7 14,8±0, 14607 14,6±0, 592 59±2 1480 14,8±0 1460 14,6±0 59± 148 14,8± 146 14,6± 14,8 14,6 14,

RESUMEN Se realizaron dos estudios en ovejas en el trópico alto de Colombia, para estudiar los parámetros reproductivos y de fertilidad asociados con el crecimiento animal, en esta zona ecológica. En el primer ensayo, se utilizaron 1.389 registros para analizar, a través de estadísticas descriptivas, los parámetros de fertilidad, la tasa de natalidad y el rendimiento por parto múltiple, de tres grupos genéticos de ovejas: las razas nativas Criolla y Manchada Paramuna y se compararon con la raza importada Blackface. En el segundo estudio, se determinó la duración del ciclo estral y se determinaron valores de progesterona sérica durante el ciclo estral, en 19 ovejas cruzadas Criolla x Romney Marsh; en este experimento, se analizaron cinco momentos del ciclo. Las tasas de fertilidad encontradas en las razas Criolla y Manchada Paramuna fue de 73,1 y 72 %, respectivamente, superior a la de las ovejas Blackface (65 %). Las ovejas Blackface mostraron la mayor incidencia de partos múltiples (29 %) y las ovejas Manchada Paramuna tuvieron las tasas de parto más altas (93,7 %). Las ovejas cruzadas Criolla x Romney Marsh registraron una duración media del ciclo estral de 17,8 d. La mayor secreción de progesterona (11,5 nmol/L) ocurrió el día 9 del ciclo estral, mientras que en las fases del estro, su valor fue de 0,32 nmol/L. Este estudio contribuye con el conocimiento de los aspectos reproductivos de las ovejas nativas colombianas.

ABSTRACT Two studies were conducted on sheep in the high tropics of Colombia to study reproductive and fertility parameters associated with animal growth in this ecological zone. In the first trial, 1,389 records were used to analyze, through descriptive statistics, the fertility parameters, the birth rate, and the yield per multiple births of three genetic groups of sheep: the native Criolla and Manchada Paramuna breeds, and they were compared with the imported race Blackface. In the second study, the duration of the estrous cycle was determined and serum progesterone values were determined during the estrous cycle in 19 Criolla x Romney Marsh crossbred ewes, in this experiment, five moments of the cycle were analyzed. The fertility rates found in the Criolla and Manchada Paramuna breeds were 73.1 and 72 %, respectively, and were higher than those of the Blackface sheep (65 %). Blackface ewes showed the highest incidence of multiple births (29 %) and Manchada Paramuna ewes had the highest birth rates (93.7 %). Criolla x Romney Marsh crossbred ewes recorded a mean duration of the estrous cycle of 17.8 d. The highest progesterone secretion (11.5 nmol/L) occurred on day 9 of the estrous cycle, while in the estrus phases, its value was 0.32 nmol/L. This study contributes to the knowledge of the reproductive aspects of Colombian native sheep.

Abstract The objective of the work was to characterize the cycle of the vaginal epithelium of sheep of the Santa Inês breed, through a cytological study. Vaginal mucosal samples were taken from 10 sexually mature ewes, from the first day of estrus and for 18 days. The samples were stained with Papanicolaou and observed under an optical microscope. Parabasal, de epintermediate, superficial intermediate, and superficial cells were recognized. The parabasal cells presented a rounded shape, little cytoplasm, and a large nucleus, they were scarce. The deep intermediate ones with rounded edges, more abundant cytoplasm, and smaller nuclei. They were observed in greater quantity than the parabasal ones. The superficial intermediate ones were the most abundant through out the study and the one swith the largest diameter. They presented a polygonal shape and a smaller nucleus. The identification of two types of intermediate cells coincides with works on dogs, cows, and alpacas, while other works describe a single type. Superficial cells were divided into two subtypes, A, with a polygonal shape and piknotic nucleus, and B, with a smaller and intensely acidophilic cytoplasm and pyknotic nucleus. The latter has not been found so far in other works with sheep. Changes in cell types did not accurately reflect the phase of the estrous cycle.

Resumen El objetivo de trabajo fue caracterizar el ciclo del epitelio vaginal de ovejas de raza Santa Inês, mediante estudio citológico. Se tomaron muestras de la mucosa vaginal a 10 borregas sexualmente maduras, desde el primer día de celo y por 18 días. Las muestras se colorearon con Papanicolaou y se observaron en microscopio óptico. Se reconocieron células parabasales, intermedias profundas, intermedias superficiales y superficiales. Las células parabasales presentaron forma redondeada, citoplasma escaso y núcleo grande, fueron escasas. Las intermedias profundas de bordes redondeados, citoplasma más abundante y núcleo menor. Se observaron en mayor cantidad que las parabasales. Las intermedias superficiales fueron las más abundantes en todo el estudio y las de mayor diámetro. Presentaron forma poligonal y núcleo más pequeño. La identificación de dos tipos de célula intermedia, coincide con trabajos en perras, vacas y alpacas, en tanto otros trabajos describen un solo tipo. Las células superficiales se dividieron en dos subtipos, el A, con forma poligonal y núcleo picnótico y el B, con citoplasma más pequeño e intensamente acidófilo y núcleo picnótico. Este último no se encontró hasta el momento en otros trabajos con ovejas. Las modificaciones de los tipos celulares no reflejaron de manera precisa la fase del ciclo estral.

Abstract Introduction: The low fertility is one of the greatest problems in mare reproduction. Preovulatory follicle diameter could be used as estrus predictor. Methods: Forty-three mares, 550 ± 34 kg live weight, 6.00 ± 2.30 years old, and 4.42 ± 0.39 body condition score (CC), without reproductive or sanitary problems were used to study the evolution of follicle diameter (DF) during an estrus cycle. The estrus detection and measurement of DF were done daily, mares with DF > 38 mm were inseminated, pregnancy was tested 16 d post insemination. Variables evaluated were estrus length (Dcelo) and estrus cycle (Dciclo); DF at 21 d (DF21), at start of estrus (DFcelo), and at artificial insemination (DFIA); corpora luteum diameter lúteo (DCL); and pregnancy rate (TP16). The fixed effects included in the model were age of mare, CC, Dcelo, Dciclo, number of follicles, time to estrus appearance after day 21 (Celoh), DFcelo, and DF21. The statistical analyses were carried out with the MIXED and GLIMMIX procedures of SAS. Results: Age (p ≤ 0.0221) and Dcelo (p ≤ 0.036) were significant for most of the variables analyzed. Mares 9-11 years old had the greatest Dciclo, DCL, and DF. DFcelo was significant (p ≤ 0.0056) for DCL and DF21; while DF21 was (p ≤ 0.0001) for Celoh, DFcelo, and DFIA. The follicle growth showed a cubic trend, with a reduction in growth rate days before ovulation. Conclusion: Age of mare, DF21, and DFcelo, help to predict estrus appearance. Knowledge of ovarian dynamics helps to breed mares at the right time.

Resumen Introducción: La baja fertilidad es una de las mayores dificultades que enfrenta la reproducción equina. El diámetro folicular preovulatorio puede utilizarse como predictor del celo. Métodos: Se estudió la evolución del diámetro folicular (DF) durante un ciclo estral en 43 yeguas, con 550 ± 34 kg PV, edad 6.00 ± 2.30 años y 4.42 ± 0.39 de condición corporal (CC), sin problemas reproductivos o sanitarios. Los celos se detectaron y los DF se midieron diariamente; las yeguas con DF > 38 mm se inseminaron, y la preñez se diagnosticó 16 d post inseminación. Las variables evaluadas fueron: duración del celo (Dcelo) y del ciclo estral (Dciclo); DF al día 21 (DF21), al inicio del celo (Dfcelo) y a la inseminación artificial (DFIA); diámetro del cuerpo lúteo (DCL), y tasa de preñez (TP16). Los efectos fijos incluidos en el modelo fueron: edad de la yegua, CC, Dcelo, Dciclo, número de folículos, tiempo que tardó en presentarse el celo después del día 21 (Celoh), Dfcelo, y DF21. Los análisis estadísticos se realizaron con los procedimientos MIXED y GLIMMIX de SAS. Resultados: La edad (p ≤ 0.0221) y el Dcelo (p ≤ 0.036) fueron significativas para la mayoría de las variables de respuesta analizadas. Las yeguas de 9-11 años tuvieron los mayores Dciclo, DCL y DF. La covariable Dfcelo fue significativa (p ≤ 0.0056) para DCL y DF21; mientras que DF21 lo fue (p ≤ 0.0001) para Celoh, Dfcelo y DFIA. El crecimiento folicular mostró una tendencia cúbica, con una reducción en la tasa de crecimiento días previos a la ovulación. Conclusión: La edad de la yegua, DF21 y Dfcelo, ayudan a predecir la presentación del celo. El conocimiento de la dinámica ovárica ayuda al apareamiento al tiempo correcto en yeguas.

Abstract The aim of the study was to evaluate the effect of body condition score (BCS) at lambing over the resumption of ovarian and estrous postpartum activity in lactating Pelibuey ewes. Twenty ewes were assigned to two groups, according to the BCS at lambing: Low BCS (LBC, n = 10) and High BCS (HBC, n = 10). Ovarian and estrous activities were daily monitored from day 3 postpartum until the first estrous or 90 days postpartum. Continuous variables were analyzed using Student´s t test and binary responses with the exact Fisher test. No significant effect of BCS at lambing on ewes in estrous, lambing to first estrous interval, estrous length, and estrous cycle length, preovulatory follicles at estrous, the maximum follicular diameter at estrous day or ovulation rate was observed. However, the lambing to first preovulatory follicle interval was shorter in the HBC group (HBC = 6.2 ± 2.6 vs LBC = 10.8 ± 4.5 d; P < 0.05). The lambing to first corpus luteum intervals were similar between groups, but without estrous expression. The function of the first corpus luteum postpartum was similar in both groups. BCS at lambing did not affect the resumption of ovarian and estrous activity postpartum in lactating Pelibuey ewes.

Resumen El objetivo del estudio fue evaluar el efecto de la condición corporal (BCS) al momento del parto en la reanudación de la actividad ovárica y estral de las ovejas Pelibuey lactantes. De acuerdo con la condición corporal postparto, veinte ovejas fueron separadas en un grupo de baja BCS (LBC, n = 10) y alta BCS (HBC; n = 10). Las actividades ovárica y estral se observaron diariamente, desde el tercer día postparto hasta el primer estro o 90 días postparto. Las variables continuas se analizaron mediante la prueba t de Student y las respuestas binarias con la prueba exacta de Fisher. No se observó ningún efecto significativo de la BCS al parto, sobre la presencia de celo, intervalo parto-primer celo, duración del estro y duración del ciclo estral, presencia de folículos preovulatorios en el celo, diámetro folicular máximo en el día del celo o tasa de ovulación. Sin embargo, el intervalo entre el parto y el primer folículo preovulatorio fue más corto en el grupo HBC (HBC = 6.2 ± 2.6 vs. LBC = 10.8 ± 4.5 d; P < 0.05). El intervalo entre el parto y el primer cuerpo lúteo fueron similares entre los grupos, pero sin expresión de celo. La función del primer cuerpo lúteo postparto fue similar en ambos grupos. La BCS en el parto no afectó la reanudación de la actividad ovárica y estral postparto en ovejas Pelibuey lactantes.

RESUMEN 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 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. Por lo tanto, destetar precozmente favorece la recuperación reproductiva de las vacas.

ABSTRACT 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 × 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 × 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.

Resumen El consumo crónico de alcohol es un problema de salud mundial que afecta particularmente a la población femenina. Sin embargo, los efectos de la ingesta semicrónica en cantidades moderadas a bajas en el ovario y el oocito son poco conocidos. En un modelo murino, se administró etanol al 10% en agua de bebida (hembras tratadas) o agua (hembras control) por 15 días, y luego de la superovulación o no (ovulación espontánea), se analizó el ciclo estral y la calidad ovárico-gamética. En las hembras tratadas, la frecuencia y duración del diestro aumentó, y las frecuencias de folículos y cuerpos lúteos disminuyeron vs hembras controles, valores que se restauraron luego de la superovulación. Sin embargo, en las hembras tratadas, la tasa de proliferación celular folicular y el desbalance de la expresión ovárica de VEGF (factor de crecimiento endotelial) persistieron luego de la superovulación. El número de ovocitos ovulados con metafase II anormal, fragmentados y activados partenogenéticamente fue mayor en las hembras tratadas respecto las controles. En conclusión, el consumo semicrónico moderado de alcohol produce anestro, ciclo estral irregular, foliculogénesis deficiente y anomalías núcleo-citoplasmáticas en los oocitos ovulados. Estas alteraciones podrían constituirse en un factor etiológico de pérdida gestacional temprana y desarrollo embrionario anormal luego del consumo de alcohol.

Abstract Chronic alcohol consumption is a global health problem that particularly affects the female population. However, the ef-fects of semi-chronic ethanol intake in low-moderate amounts on the ovary and oocyte are poorly understood. In a mouse model, 10% ethanol was administered in drinking water (treated females) or water (control females) for 15 days, and after superovulation or not (spontaneous ovulation), the estrous cycle and ovarian-gametic quality were analyzed. In treated females, the frequency and duration of the diestrus increased, and the frequencies of follicles and corpus luteum decreased vs control females, values that restored after superovulation. However, in treated females, the follicular cell proliferation rate and the imbalance in ovarian expression of VEGF (endothelial growth factor) persisted after superovulation. The number of ovulated oocytes with abnormal metaphase II, fragmented and parthenogenetically activated was higher in treated females than in control ones. In conclusion, moderate semi-chronic alcohol consumption produces anestrum, irregular estrous cycle, poor folliculogenesis, and nuclear-cytoplasmic abnormalities in ovulated oocytes. These alterations could constitute an etiological factor of early gestational loss and abnormal embryonic development after alcohol consumption.

ABSTRACT Aim. To compare the efficiency of the ultrasound and direct visual techniques for antral follicle counts, and the morphological characteristics of the ovaries of slaughtered heifers. Methods: A number of 102 ovary pairs from crossbred Holstein heifers collected postmortem were included. The study used the ultrasound and direct visual techniques to determine the size and weight of the ovaries, luteal body, and the number of <4 mm >4 mm antral follicles. A simple analysis of variance and the Tukey test at 5% were performed to compare the means of the variables pooled by phase of the estrus cycle and follicular wave. A two-way analysis of variance was performed to compare the two techniques and location of the ovarian structures (RO and LO). Additionally, the Pearson test was conducted to establish the correlation between the techniques. Results: The study found that the right ovary (RO) weighed 3.21 g more than the left ovary (LO). Besides, 86.27% of animals presented luteal body (LB) with a mean weight of 3.38 g. The size of ovaries, (LB), and > 4 mm antral follicle counts (AFC) performed through direct visual (Vis) and ultrasound (US) techniques were similar (P>0.05), with a high and significant correlation (r=0.75; P<0.001). However, the <4 mm AFC showed statistically significant differences (P<0.05) between the techniques, whereas the correlation was low and non-significant. Conclusion: Ultrasound is a highly efficient tool to assess > 4 mm ovarian structures. However, the correct determination of smaller structures will depend on other additional factors.

RESUMEN Objetivo. Comparar la eficiencia de la técnica ultrasonográfica con la visual directa en el recuento de folículos antrales y las características morfológicas ováricas de vaquillas sacrificadas. Métodos: Se utilizaron 102 pares de ovarios de vaquillas Holstein mestizas, recuperados post-mortem. Mediante las técnicas ultrasonográfica y visual directa se determinó tamaño y peso del ovario, cuerpo lúteo y número de folículos antrales <4 mm y >4 mm. Se aplicó un análisis de varianza simple (ANOVA) y la prueba de Tukey al 5% para comparar medias de las variables agrupadas por fase del ciclo estral y fase de onda folicular y para comparar las técnicas y ubicación de las estructuras ováricas (OD y OI) se utilizó un análisis de varianza de dos vías. Además, se aplicó la prueba de Pearson para establecer correlación entre las dos técnicas. Resultados: Se determinó que el ovario derecho (OD) pesó 3,21 g más que el ovario izquierdo (OI). Además, el 86,27% de los animales presentaron cuerpo lúteo (CL), con peso medio de 3,38 g. El tamaño de los ovarios, CL y el recuento de folículos antrales (RFA) >4 mm establecidos mediante las técnicas visual directa (Vis) y ultrasonográfica (US) fueron similares (P>0,05) y guardaban correlación alta y significativa (r=0,75; P<0,001). Sin embargo, el RFA <4 mm presentaron diferencia estadística (P<0,05) entre las dos técnicas y la correlación fue baja y no significativa. Conclusión: La ultrasonografía es una herramienta con una alta eficiencia en la valoración de estructuras ováricas mayores a 4 mm. Sin embargo; la determinación correcta de estructuras menores, va a depender de otros factores adicionales.

ABSTRACT 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.

RESUMEN Introducción: La citología vaginal directa es un método muy utilizado para la evaluación del ciclo estral de las ratas de laboratorio, pero la información acerca de los procedimientos e interpretación de los resultados aparece disgregada en la literatura, lo cual dificulta su empleo en los estudios de reproducción. Objetivo: Proponer un protocolo para la realización de la citología vaginal directa de ratas de laboratorio y la interpretación de los resultados. Material y métodos: Se combinó la información de la literatura y la experiencia de 10 años de estudios de reproducción, en los que se han empleado un total de 250 ratas Wistar hembras, siguiendo preceptos éticos establecidos. Se describen los procedimientos para la obtención de las muestras, mediante lavado vaginal, así como para su observación y análisis en estado húmedo, con microscopio óptico y cámara digital acoplada. Resultados: Se describen los tipos celulares principales presentes en el lavado vaginal y las características que permiten identificar cada fase o estado de transición del ciclo estral. Se discuten aspectos a considerar en la interpretación de los resultados, que incluye la relación con los cambios hormonales, los cuidados en la obtención de la muestra y la influencia de factores ambientales. Se muestran imágenes y figuras representativas para ilustrar el texto. Conclusiones: El trabajo constituye un protocolo para el estudio del ciclo estral de ratas de laboratorio, mediante la citología vaginal directa. Provee métodos no invasivos, sencillos y económicos, así como conocimientos esenciales para la interpretación de los resultados, que integran una guía de gran utilidad para los estudios experimentales de reproducción.