Altrenogest treatment during the last week of lactation on ovarian traits and subsequent reproductive performance of primiparous and multiparous sows.

High-quality follicles result in larger corpora lutea (CL), producing more progesterone, and having a fundamental role in pregnancy maintenance. For some sows, follicular growth takes place during lactation, and follicle selection occurs under a catabolic environment. As altrenogest inhibits follicular development, this study aimed to evaluate follicular growth, CL size, estrus expression, and subsequent reproductive performance of sows treated with altrenogest during the last seven days of a three-week lactation. A total of 81 primiparous and 319 multiparous sows were allocated to two treatments: CONT (control group) and ALT (20 mg of altrenogest/day during the last seven days of lactation). Subsamples of 20 primiparous sows and 97 multiparous were randomly selected to evaluate follicular growth and 26 multiparous sows for serum progesterone analysis at day 21 of gestation. On day 21 of pregnancy, CL measurement was performed by ultrasound. Once in estrus, sows were post-cervically inseminated with pooled semen doses with 1.5 × 109 sperm cells at estrus onset and every 24 h during the standing reflex period. Sows not showing estrus until 10 days after weaning were considered in anestrus. The variables weaning-to-estrus interval, CL size, litter size in the subsequent cycle, and piglet birth weight were evaluated using the GLIMMIX procedure and compared using the Tukey-Kramer test. Anestrus, pregnancy, farrowing, and adjusted farrowing rate were evaluated as binary responses using logistic regression. Follicular size was analyzed as a repeated measure during treatment and after weaning. Treatment was considered as a fixed effect. During the treatment period, follicular size was smaller in ALT sows than CONT sows (3.29 vs. 3.52 mm; P < 0.001). However, after treatment, ALT sows showed a larger follicular size than CONT sows (5.30 vs. 5.03 mm; P ≤ 0.01). There were less ALT sows showing estrus than CONT sows on days three (1.03 vs. 4.57%) and four (55.38 vs. 68.02%) after weaning (P ≤ 0.05), respectively. At 21 days after insemination, ALT sows showed larger CL size and lower CL size variation (P < 0.01) than CONT sows. Anestrus rate, pregnancy rate, farrowing rate, adjusted farrowing rate, litter size in the subsequent cycle, piglet birth weight, litter birth weight, and birth weight variation did not differ between treatments (P ≥ 0.14). In conclusion, altrenogest treatment during the last week of lactation concentrated estrus expression on day five after weaning, larger follicle and CL sizes; however, with no improvement in reproductive performance.

First assessment of hoary fox (Lycalopex vetulus) seasonal ovarian cyclicity by non-invasive hormonal monitoring technique.

Reproduction is key to species survival, and reproductive physiology represents a high priority investigative area for conservation biology, as it provides a basic understanding of critical life-history traits, information that is helpful for the establishment of management strategies. Here, we generated knowledge about the reproductive endocrinology of the hoary fox (Lycalopex vetulus), a small canid (2.5-4 kg) endemic to open areas of the Brazilian Cerrado and listed in the Brazilian National List of Endangered species. Specifically, we utilized non-invasive hormone monitoring methods to assess oestrogen and progestagen metabolites from eight female hoary foxes housed in five zoological institutions in the state of São Paulo-Brazil. We observed the elevations of oestrogen and progestagen metabolites between July and September in six of the eight females. No significant evidence of ovarian activity was observed during other months. Two females, who shared the same enclosure, did not show a pattern of reproductive cyclicity. Based on these characteristics, we concluded that captive hoary foxes are seasonal monoestric, with the beginning of the oestrus cycle occurring mainly in July followed by 2 months of the luteal phase when conception does not occur. We suggest the dosage of faecal metabolites of estradiol and progesterone could be used to differentiate the reproductive period from a non-reproductive period in Lycalopex vetulus females, providing relevant information about their reproductive biology that may contribute to species conservation and management strategies, such as increased ex situ reproductive success.

Supplemental progesterone during early pregnancy exerts divergent responses on embryonic characteristics in sows and gilts.

Progesterone (P4) plays a key role in pregnancy establishment and maintenance; during early pregnancy, P4 stimulates the production and release of uterine secretions necessary for conceptus growth prior to implantation; therefore, exogenous P4 supplementation may improve embryo development. This study evaluated the effects of supplementation during early pregnancy with long-acting injectable progesterone or altrenogest on embryonic characteristics of sows and gilts. Thus, a total of 32 sows and 16 gilts were used. On day 6 of pregnancy sows and gilts were allocated to one of the following groups: non-supplemented; supplemented with 20 mg of altrenogest, orally, from days 6 to 12 of pregnancy; supplemented with 2.15 mg/kg of long-acting injectable progesterone on day 6 of pregnancy. Animals were killed on day 28 of pregnancy, and ovulation rate, embryo survival, embryo weight, crown-to-rump length, uterine glandular epithelium and endometrial vascularization were assessed. Treatments had no effect on pregnancy rate, embryo survival or endometrial vascular density (P > 0.05). Non-supplemented gilts presented larger and heavier embryos compared to gilts from supplemented groups (P < 0.05). Sows in the altrenogest group presented larger and heavier embryos compared to non-supplemented sows and sows supplemented with long-acting injectable progesterone. In conclusion, supplementation of sows and gilts with progestagen from day 6 of pregnancy can be used as a means to improve embryo survival without deleterious effects.

Altrenogest en cerdas primíparas: efecto sobre la aparición de celo y el tamaño de la camada

El objetivo del presente trabajo fue evaluar el efecto del tratamiento con Altrenogest sobre la aparición de celo y el tamaño de la camada en cerdas primíparas. Setenta y dos hembras (Landrace x Yorkshire) con un peso promedio de 155 ± 5 kg se asignaron aleatoriamente en dos grupos: GT = grupo tratamiento (n=36), al cual se le aplicó un protocolo de sincronización de celo con Altrenogest durante 18 días (20 mg/día) sobre el alimento y GC = grupo control (n=36). Se registró la concentración de los celos del grupo tratamiento para medir la eficacia del progestágeno. El número de lechones nacidos vivos (LNV), muertos (LNM) y totales (LNT) fue registrado en ambos grupos para su comparación a través de un ANOVA, usando el software estadístico INFOSTAT. No se encontraron diferencias significativas para el número de LNM y LNT, mientras que el número de LNV se vio favorecido por el tratamiento (p<0.05). El 91% de los celos se concentraron entre el cuarto y quinto día de finalizado la administración del progestágeno. Podemos concluir que el tratamiento con Altrenogest en cerdas primíparas, mejoró el número de LNV a la vez que logra concentrar eficazmente la presentación de celos entre los días 4 y 6 post-tratamiento.

The objective of this study was to evaluate the effect of Altrenogest administration on estrus manifestation and litter size of primiparous sows. Seventy-two primiparous sows (Landrace x Yorkshire) with a weight of 155 ± 5 kg were randomly assigned to two groups: 1) GT or treatment group (n=36) that received Altrenogest administration during 18 days (20 mg./day) in the food and 2) GC or control group (n=36). Estrus manifestation was recorded as well as number of piglets born alive, stillborn and litter size. ANOVA was used for mean comparisons using INFOSTAT statistical software. No differences between treatments were observed for number of stillborn and litter size whereas number of piglets born alive was increased by Altrenogest administration (p<0.05). Estrus manifestation was observed between fourth and sixth day following Altrenogest treatment. We can conclude that the treatment of Altrenogest in primiparous sows improved the number of piglets born alive and synchronized estrus.

Use of human intravaginal tampon embedded with natural progesterone induces synchronous estrus in Santa Inês ewes / Uso de tampão intravaginal humano embebido com progesterona humana para indução e sincronização de estro em ovelhas Santa Inês

Este estudo avaliou a eficiência de três protocolos de indução de estro síncronizado em ovelhas da raça Santa Inês. Vinte e quatro ovelhas adultas foram equitativamente distribuídas em três grupos, de acordo com ordem de parto, peso corporal (kg) e escore da condição corporal. As ovelhas receberam implante vaginal de progesterona natural por seis dias mais 37,5µg de d-cloprostenol laterovulvar e 300UI de eCG i.m., 24 horas antes da remoção do dispositivo. Ovelhas controle receberam CIDR330mg de progesterona, e as demais receberam dispositivo absorvente intravaginal humano, tamanho mini, embebido com 200 (OB200) ou 400mg (OB400) de progesterona. Coletas de sangue foram feitas nos momentos D0 (antes da inserção dos dispositivos), D0+6h e diariamente, até um dia após retirada do dispositivo (D7). A progesterona (ng/mL) foi semelhante (P>0,05) em todos os tratamentos ao longo do período experimental, exceto no dia da remoção do dispositivo, quando as ovelhas controle (2,5±0,3) tiveram progesterona superior (P<0,05) às ovelhas OB200 (0,6±0,1) e OB400 (1,2±0,4). O percentual de animais em estro (100,0, 62,5 e 100,0%) foi semelhante (P>0,05) e o intervalo para o estro (46,3±3,9a, 26,4±4,5b e 31,2±5,8a,b) foi diferente (P<0,05) entre os animais dos grupos controle, OB200 e OB400, respectivamente. A taxa de concepção das ovelhas foi de 50,0% (4/8) para cada grupo (P>0,05). Dispositivos humanos e fonte de progesterona podem ser usados para induzir o estro sincronizado em ovelhas Santa Inês.(AU)

Prepartum progestagen supplementation in swine: a strategy to facilitate piglet care and prevent early parturition / Suplementação de progestágenos no pré-parto em suínos: estratégia para facilitar assistência aos leitões e evitar partos precoces

Gestation length in swine has a considerable amplitude and both early and delayed parturition are common. This variation increases the occurrence of unassisted farrowing and could lead to a wide-ranging age at weaning for piglets born from one batch. Supervision of sow parturition is crucial to reduce mortality of neonate piglets. To facilitate assistance, induction of farrowing using prostaglandin F2α (PGF) has been widely used in batch farrowing systems, whereby synchronization would concentrate the time of farrowing, allowing for better organization of employees. However, a viable alternative method that can be implemented to manage farrowing is to sustain high progestagen levels in the final days of gestation and, consequently, prevent early parturition. Efficient techniques to delay farrowing such as using oral progestagen supplementation have been previously described, but are only recently being considered for commercial use. The present manuscript reviews publications regarding delaying parturition and discusses the use of intravaginal devices (IVDs) containing progestagen. There is limited data addressing the effect of progestagen treatment during gestation on productive and reproductive performance. Therefore, future studies should focus on improving synchronization protocols following progestagen supplementation and evaluating piglet viability and sow fertility, before widely using progestagen supplementation to manipulate parturition.(AU)

Como a duração da gestação de suínos pode ter ampla variação, é comum a ocorrência de partos antecipados ou gestações prolongadas. Isso aumenta as chances de partos sem assistência e leva a uma grande variação de idade dos leitões dentro do lote de produção. Portanto, a supervisão do parto é indispensável para reduzir as perdas neonatais. Para facilitar o auxílio aos leitões, a indução do parto com prostaglandina F2α (PGF) é eficaz e amplamente utilizada, sendo indicada para concentrar os partos em momentos mais adequados, preferencialmente durante o horário com maior disponibilidade de colaboradores. Uma alternativa viável é manipular o momento do parto, através da manutenção de níveis plasmáticos elevados de progestágeno durante o final da gestação, a fim de evitar partos antecipados. Formas eficientes de evitar o parto através de suplementação oral de progestágenos foram descritas há décadas, mas apenas recentemente tem sido cogitada a utilização comercial. A presente revisão aborda estudos disponíveis na literatura relacionados ao protelamento do parto, incluindo a utilização de dispositivos intravaginais (DIVs) impregnados com progestágeno. São poucos os dados disponíveis relacionados ao uso de progestágenos na gestação com índices produtivos e reprodutivos. Portanto, alguns pontos ainda devem ser melhor avaliados, especialmente com relação à determinação da sincronia dos partos após o fim da suplementação com progestágenos, à viabilidade dos neonatos e à fertilidade subsequente das fêmeas antes da ampla adoção desta técnica.(AU)

Prepartum progestagen supplementation in swine: a strategy to facilitate piglet care and prevent early parturition / Suplementação de progestágenos no pré-parto em suínos: estratégia para facilitar assistência aos leitões e evitar partos precoces

ABSTRACT: Gestation length in swine has a considerable amplitude and both early and delayed parturition are common. This variation increases the occurrence of unassisted farrowing and could lead to a wide-ranging age at weaning for piglets born from one batch. Supervision of sow parturition is crucial to reduce mortality of neonate piglets. To facilitate assistance, induction of farrowing using prostaglandin F2α (PGF) has been widely used in batch farrowing systems, whereby synchronization would concentrate the time of farrowing, allowing for better organization of employees. However, a viable alternative method that can be implemented to manage farrowing is to sustain high progestagen levels in the final days of gestation and, consequently, prevent early parturition. Efficient techniques to delay farrowing such as using oral progestagen supplementation have been previously described, but are only recently being considered for commercial use. The present manuscript reviews publications regarding delaying parturition and discusses the use of intravaginal devices (IVDs) containing progestagen. There is limited data addressing the effect of progestagen treatment during gestation on productive and reproductive performance. Therefore, future studies should focus on improving synchronization protocols following progestagen supplementation and evaluating piglet viability and sow fertility, before widely using progestagen supplementation to manipulate parturition.

RESUMO: Como a duração da gestação de suínos pode ter ampla variação, é comum a ocorrência de partos antecipados ou gestações prolongadas. Isso aumenta as chances de partos sem assistência e leva a uma grande variação de idade dos leitões dentro do lote de produção. Portanto, a supervisão do parto é indispensável para reduzir as perdas neonatais. Para facilitar o auxílio aos leitões, a indução do parto com prostaglandina F2α (PGF) é eficaz e amplamente utilizada, sendo indicada para concentrar os partos em momentos mais adequados, preferencialmente durante o horário com maior disponibilidade de colaboradores. Uma alternativa viável é manipular o momento do parto, através da manutenção de níveis plasmáticos elevados de progestágeno durante o final da gestação, a fim de evitar partos antecipados. Formas eficientes de evitar o parto através de suplementação oral de progestágenos foram descritas há décadas, mas apenas recentemente tem sido cogitada a utilização comercial. A presente revisão aborda estudos disponíveis na literatura relacionados ao protelamento do parto, incluindo a utilização de dispositivos intravaginais (DIVs) impregnados com progestágeno. São poucos os dados disponíveis relacionados ao uso de progestágenos na gestação com índices produtivos e reprodutivos. Portanto, alguns pontos ainda devem ser melhor avaliados, especialmente com relação à determinação da sincronia dos partos após o fim da suplementação com progestágenos, à viabilidade dos neonatos e à fertilidade subsequente das fêmeas antes da ampla adoção desta técnica.

Oxidative status and fertility of ewes supplemented coffee pulp during estrous ¤ synchronization and early pregnancy / Estado oxidativo y fertilidad en ovejas suplementadas con pulpa de café durante la sincronización estral y gestación temprana / Estado oxidativo e fertilidade nas ovelhas suplementadas com a polpa de café durante sincronização do estro e gestação inicial

Summary Background: it is known that coffee pulp can modify the oxidative status and fertility in dairy cows. Objective: to evaluate the effect of dietary supplementation with coffee pulp on the antioxidant capacity, lipid oxidation and reproductive characteristics of ewes during estrous synchronization and early gestation. Methods: forty Dorset-Suffolk crossbred ewes with 3 or 4 parturitions were allocated to two treatments: T0 (n = 21), ewes supplemented with 450 g of a control feed; and T1 (n = 19), ewes supplemented with 450 g of the feed with 25% coffee pulp. Supplementation began 14 days before estrous synchronization and ended 25 days after breeding. During estrous synchronization, progestogen (CIDR, Controlled Internal Drug Release) was inserted and left in situ for 11 days. Eighteen hours later, estrous detection began with the aid of rams. Blood samples were collected at different times of synchronization and during early pregnancy to determine antioxidant capacity, lipid oxidation and blood progesterone concentration. Pregnancy diagnosis was performed 30 and 60 days after CIDR removal. Results: supplementation with coffee pulp did not affect estrous onset, estrous response or progesterone concentration, but fertility decreased from 100 to 78.95%. The antioxidant capacity measured using the FRAP technique was greater in coffee pulp supplemented ewes only before progestogen insertion. Coffee pulp did not modify lipid oxidation; however, this variable was affected by sampling time, decreasing after progestogen removal to its lowest values at 22 days into pregnancy. Conclusion: although supplementation with coffee pulp at 25% in the concentrate increased antioxidant capacity of ewes before insertion of progestogen, it is not recommended to use this percentage during synchronization or early pregnancy since it can negatively affect gestation rate.

Resumen Antecedentes: se sabe que la pulpa de café puede modificar el estado oxidativo y la fertilidad en vacas lecheras. Objetivo: evaluar los efectos del suministro dietario de pulpa de café y su capacidad antioxidante, oxidación lipídica, y características reproductivas en ovejas durante la sincronización del estro y la gestación temprana. Métodos: cuarenta ovejas cruzadas Suffolk x Dorset de 3 y 4 partos fueron asignadas a dos grupos: T0 (n = 21), suplementación con 450 g de alimento (grupo testigo); y T1 (n = 19), suplementación con 450 g de alimento con 25% de pulpa de café. La suplementación inició 14 días antes de la sincronización del estro y terminó 25 días después del apareamiento. El progestágeno (CIDR, Dispositivo Intravaginal de Liberación Controlada) fue insertado en los animales por 11 días. Dieciocho horas después de su retiro se inició la detección de estros. Se muestreó a diferentes tiempos después de la sincronización y durante la gestación temprana para determinar capacidad antioxidante, oxidación lipídica y concentración de progesterona. El diagnóstico de preñez se realizó 30 y 60 días después de la remoción del CIDR. Resultados: la suplementación con pulpa de café no afectó el inicio del estro, la respuesta al estro ni la concentración de progesterona. Sin embargo, la fertilidad disminuyó de 100 a 78,95%. La capacidad antioxidante, medida mediante la técnica FRAP, fue mayor en ovejas suplementadas con pulpa de café, pero solo antes de la inserción del progestágeno. La pulpa de café no modificó la oxidación lipídica; sin embargo, si fue modificada por el tiempo de muestreo, decreciendo desde la remoción del progestágeno hasta los 22 días de preñez. Conclusión: aunque la suplementación del concentrado con 25% de pulpa de café incrementó la capacidad antioxidante antes de la inserción del progestágeno, no se recomienda ese porcentaje durante la sincronización y gestación temprana, ya que redujo el porcentaje de gestación de las ovejas.

Resumo Antecedentes: a polpa de café pode modificar o estado oxidativo e a fertilidade em vacas leiteiras. Objetivo: avaliar a polpa de café na capacidade antioxidante, oxidação da gordura e nas características reprodutivas das ovelhas durante sincronização do estro e gestação inicial. Métodos: quarenta ovelhas cruzas Suffolk e Dorset de 3 e 4 nascimentos foram agrupadas no T0 (n = 21), suplementação com 450 g de alimento controle e T1 (n = 19), suplementação com 450 g de alimento com 25% de polpa de café. A suplementação iniciou 14 dias antes da sincronização do estro e terminou 25 dias depois do acasalamento. O hormônio progestina (CIDR, dispositivo intravaginal de libertação controlada de fármaco) foi inserido por 11 dias. Dezoito horas depois da retirada iniciouse a detecção do estro. Fizeram-se amostras de diferentes tempos do período e da gestação inicial para determinar a capacidade antioxidante, oxidação dos lipídeos e concentração de progesterona. Realizou-se o diagnóstico de gestação 30 e 60 dias depois de remover o CIDR. Resultados: a suplementação com a polpa de café não afetou o início do estro, a resposta ao estro e a concentração de progesterona, mas a fertilidade decresceu de 100 a 78,95%. A capacidade antioxidante que foi medida pela técnica de FRAP foi maior nas ovelhas suplementadas com a polpa de café somente antes da inserção do progestágeno. A polpa de café não modificou a oxidação dos lipídeos; no entanto, estes foram modificados pelo tempo de amostra, decrescendo depois de remover o progestágeno até 22 dias de gestação. Conclusão: ainda que a polpa de café a 25% de concentração incrementa a capacidade antioxidante antes da inserção do progestágeno, não é recomendado este percentual para as ovelhas durante a sincronização do estro e a gestação inicial, já que decresce a porcentagem de gestação.

Oestrogens and Progestagens: Synthesis and Action in the Brain.

When steroids, such as pregnenolone, progesterone and oestrogen, are synthesised de novo in neural tissues, they are more specifically referred to as neurosteroids. These neurosteroids bind specific receptors to promote essential brain functions. Pregnenolone supports cognition and protects mouse hippocampal cells against glutamate and amyloid peptide-induced cell death. Progesterone promotes myelination, spinogenesis, synaptogenesis, neuronal survival and dendritic growth. Allopregnanolone increases hippocampal neurogenesis, neuronal survival and cognitive functions. Oestrogens, such as oestradiol, regulate synaptic plasticity, reproductive behaviour, aggressive behaviour and learning. In addition, neurosteroids are neuroprotective in animal models of Alzheimer's disease, Parkinson's disease, brain injury and ageing. Using in situ hybridisation and/or immunohistochemistry, steroidogenic enzymes, including cytochrome P450 side-chain cleavage, 3ß-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase, cytochrome P450arom, steroid 5α-reductase and 3α-hydroxysteroid dehydrogenase, have been detected in numerous brain regions, including the hippocampus, hypothalamus and cerebral cortex. In the present review, we summarise some of the studies related to the synthesis and function of oestrogens and progestagens in the central nervous system.

Desafios fisiológicos da reprodução de felídeos selvagens / Physiological challengesin reproduction ofwild felids

O sucesso das técnicas de reprodução assistida (ARTs) em felídeos selvagens ainda é baixo, com taxas de prenhez inferiores a 10% após o uso da inseminação artificial (IA) ou da fertilização in vitro/transferência de embriões (FIV/TE). Considerando-se as pequenas populações isoladas mantidas em cativeiro e as dificuldades logísticas e sanitárias relacionadas com o transporte de animais vivos, a aplicação dessas técnicas de reprodução com eficiência torna-se essencial para o manejo reprodutivo ex situ de felídeos. Um dos desafios a ser vencido é a variabilidade no mecanismo de ovulação entre espécies, sendo que algumas apresentam ovulações espontâneas com maior frequência. Essa variabilidade traz, como consequência, respostas também muito distintas após a aplicação de gonadotropinas exógenas para indução do desenvolvimento folicular e da ovulação. Uma alternativa para melhorar a consistência das respostas endócrino-ovarianas é a utilização de progestinas previamente ao protocolo hormonal. Novas alternativas vão surgindo para tornar os procedimentos de reprodução assistida em felídeos mais práticos e efetivos. O treinamento de equipes habilitadas para realizar tais procedimentos, nas diversas regiões, é essencial para o manejo reprodutivo das populações em cativeiro, a fim de sempre maximizar a manutenção da diversidade genética.

The success of assisted reproduction techniques (ARTs) in wild felids is still low, with pregnancy rates below 10% after the use of AI or IVF/ET. Considering the small isolated populations kept in captivity, and logistical and sanitary difficulties related to the transport of live animals, the application of these reproduction techniques effectively becomes essential for the reproductive management of captive felid populations. One of the challenges to overcome is the variability in the mechanism of ovulation between species: some of which exhibit spontaneous ovulations more frequently. This variability also brings, as a consequence, very different responses after application of exogenous gonadotropins to induce follicular development and ovulation. One alternative for improving the consistency of endocrine-ovarian response is the use of progestins prior to the hormonal protocol. New alternatives emerge to make assisted reproduction in felids more practical and effective. Training qualified teams to perform such procedures, in different regions, is essential to the reproductive management of captive populations, always aiming to maximize the maintenance of genetic diversity.

Desafios fisiológicos da reprodução de felídeos selvagens / Physiological challengesin reproduction ofwild felids

O sucesso das técnicas de reprodução assistida (ARTs) em felídeos selvagens ainda é baixo, com taxas de prenhez inferiores a 10% após o uso da inseminação artificial (IA) ou da fertilização in vitro/transferência de embriões (FIV/TE). Considerando-se as pequenas populações isoladas mantidas em cativeiro e as dificuldades logísticas e sanitárias relacionadas com o transporte de animais vivos, a aplicação dessas técnicas de reprodução com eficiência torna-se essencial para o manejo reprodutivo ex situ de felídeos. Um dos desafios a ser vencido é a variabilidade no mecanismo de ovulação entre espécies, sendo que algumas apresentam ovulações espontâneas com maior frequência. Essa variabilidade traz, como consequência, respostas também muito distintas após a aplicação de gonadotropinas exógenas para indução do desenvolvimento folicular e da ovulação. Uma alternativa para melhorar a consistência das respostas endócrino-ovarianas é a utilização de progestinas previamente ao protocolo hormonal. Novas alternativas vão surgindo para tornar os procedimentos de reprodução assistida em felídeos mais práticos e efetivos. O treinamento de equipes habilitadas para realizar tais procedimentos, nas diversas regiões, é essencial para o manejo reprodutivo das populações em cativeiro, a fim de sempre maximizar a manutenção da diversidade genética.(AU)

The success of assisted reproduction techniques (ARTs) in wild felids is still low, with pregnancy rates below 10% after the use of AI or IVF/ET. Considering the small isolated populations kept in captivity, and logistical and sanitary difficulties related to the transport of live animals, the application of these reproduction techniques effectively becomes essential for the reproductive management of captive felid populations. One of the challenges to overcome is the variability in the mechanism of ovulation between species: some of which exhibit spontaneous ovulations more frequently. This variability also brings, as a consequence, very different responses after application of exogenous gonadotropins to induce follicular development and ovulation. One alternative for improving the consistency of endocrine-ovarian response is the use of progestins prior to the hormonal protocol. New alternatives emerge to make assisted reproduction in felids more practical and effective. Training qualified teams to perform such procedures, in different regions, is essential to the reproductive management of captive populations, always aiming to maximize the maintenance of genetic diversity.(AU)

Brief communication: effect of post-mating progestagen administration on pregnancy rate in crossbred goats following an induced estrus

Los celos inducidos con progesterona o progestagenos son de menor fertilidad en comparación con los celos naturales. Sin embargo, la administración postmonta de progesterona ha sido reportada por incrementar el desarrollo embrionario y la tasa de preñez; por lo tanto, el propósito de este estudio fue evaluar el efecto de la administración postmonta de un progestageno sobre la tasa de preñez en cabras mestizas tropicales luego de un celo inducido con acetato de medroxiprogestrona (MAP) durante el periodo temprano postparto. La inducción del celo se inicio el día 31,3 ± 1,7 postparto mediante la utilización de esponjas intravaginales impregnadas con 60 mg de MAP durante 14 días y al momento del retiro de las esponjas se aplicaron 500 UI de eCG, vía intramuscular. El celo fue detectado cada seis horas a partir de 24 horas de retiradas las esponjas. El servicio se realizó por monta natural con dos machos enteros. Cinco días luego de la monta, las cabras servidas fueron distribuidas de forma aleatoria en dos grupos, el grupo control (n=18), sin tratamiento; y el grupo MAP (n=18), que recibió una esponja con 60 mg de MAP por 14 días. El diagnóstico ultrasonográfico de preñez se realizó a los 50 días postmonta. El tratamiento con MAP no afectó la tasa de preñez, con 44,4 por ciento (8/18) en el grupo MAP, mientras que en el grupo control fue de 55,5 por ciento (10/18), P>0,05. En conclusión, el tratamiento con una esponja impregnadas con 60 mg de MAP entre los días 5 y 19 postmonta no afectó la tasa de preñez luego de un celo inducido durante el período postparto temprano en cabras mestizas tropicales.

Estrus induced with progesterone or progestagens have low fertility compared to natural estrus. However, post-mating progesterone administration has been reported by increases embryo development and pregnancy rate; therefore the aim of this study was to evaluate the effect of post-mating progestagen administration on pregnancy rate after medroxyprogesterone acetate (MAP) induced estrus in crossbred goats. Estrus induction was started at 31.3 ± 1.7 days post-partum with intra- vaginal sponges impregnated with 60 mg of MAP during 14 days and at time of sponge removal were applied 500 IU of eCG intramuscular. Estrus was detected every 6 hours from 24 hours onwards after sponge withdrawal. Goats were naturally mated with two entry bucks. Five days post-mating, mated goats were randomly assorted into two groups, control group (n=18), without any treatment, and MAP group (n=18), receiving a sponge with 60 mg of MAP for fourteen days. Ultrasonographyc diagnosis of pregnancy was performed at day 50 post-mating. MAP treatment, did not affect the pregnancy rate, with 44.4% (8/18) in MAP group, while in control group was 55.5% (10/18), P>0.05. In conclusion, MAP treatment with a sponge impregnated with 60 mg of MAP between days 5 and 19 post-mating did not affect the pregnancy rate after progestagen induced estrus during the early post-partum period in crossbred tropical goats.

Efecto de los días postparto, predominio racial, número de partos y época del año sobre la respuesta reproductiva de vacas mestizas en anestro tratadas con un progestágeno intravaginal más ecg y pgf2a / Effect of days postpartum, breed, parity and season on reproductive performance of anestrous crossbred cows treated with an intravaginal progestagen plus ecg and pgf2a

Para evaluar el efecto de los días postparto al tratamiento (DPP), predominio racial (PR), número de partos (NP) y época del año (E) sobre la ciclicidad y fertilidad de vacas mestizas en anestro tratadas con esponjas intravaginales (EI) impregnadas con Medroxi-acetato progesterona (MAP) más una inyección de eCG y PGF2a; se condujo un experimento en una finca ubicada en un bosque húmedo-tropical en el municipio Machiques de Perijá-Zulia, Venezuela. Se seleccionaron 72 vacas mestizas Bos taurus × Bos indicus primíparas (47) y multíparas (25) entre 45 y 108 días postparto (DPP) y condición corporal (CC) entre 3 y 3,5. Las vacas recibieron el siguiente esquema hormonal: Día 0: inserción de la EI, inyección de 5 mg de 17b-Estradiol y 50 mg de MAP im; Día 6: 500 UI de eCG y 25 mg de PGF2a im; Día 8: retiro de la EI; Día 9: 1 mg de 17b-Estradiol im. Un grupo fue tratado antes de los 70 DPP (MAP < 70DPP; n = 25) y otro después de los 70 DPP (MAP > 70DPP; n = 47). Se estudió la tasa de sincronización (TS), fertilidad al primer servicio (F), fertilidad global (FG), Intervalo Tratamiento-Concepción (ITC), Intervalo Parto-Concepción (IPC) y periodo de sincronización (PS). Las variables TS, F, y FG se analizaron con PROC LOGISTIC, SAS; mientras que ITC, IPC y PS con PROC GLM, SAS. No se encontró efectos del PR y NP sobre la TS, F, FG, ITC, IPC y PS. Las vacas con PR Bos indicus presentaron mayor F y FG en el grupo MAP < 70DPP comparada con MAP > 70DPP (F: 81,8 vs 43,7%; FG: 84,6 vs 45,5%). La TS fue mayor en las vacas tratadas en la época lluviosa comparada con la seca (96,4 vs 69,8%). La F solo fue mayor en la época lluviosa cuando las vacas fueron tratadas antes de 70DPP vs MAP > 70DPP (87,5 vs 42,1%). El PS fue menor en la época seca (36,9 h) vs la época lluviosa (48,8 h). El IPC fue menor en MAP < 70DPP (95,8 días) comparado con MAP > 70DPP (148,3 días). En conclusión, los días postparto al momento de la aplicación de la EI fue el factor que más ...

An experiment was done to evaluate the effect of postpartum interval to treatment (DPP) breed (PR), number of calving (NP) and season (E) on ciclicity and fertility of anestrous crossbred cows treated with intravaginal sponges (EI) impregnated with progesterone medroxi acetate (MAP) plus im injection of eCG and PGF2a. The study was conducted in a farm located in a tropical rainforest in Machiques de Perijá, Venezuela. Seventy two primiparous (47) and multiparous (25) Bos taurus × Bos indicus crossbred cows, between 45 and 108 days postpartum (DPP) and body condition (CC) between 3.0 and 3.5. Cows were treated as follows: MAP; Day 0, EI insertion + 5 mg 17b-Estradiol and 50 mg MAP im; Day 6, 500 IU eCG and 25 mg PGF2a im; day 8 EI removed; day 9 1 mg 17b-Estradiol im. One group was treated before 70 DPP (MAP < 70DPP; n = 25) and another after 70 DPP (MAP > 70DPP; n = 47). Studied variables were: Synchronization rate (TS), first service conception rate (F), total pregnancy rate (FG), treatment to conception interval (ITC), calving to conception interval (IPC) and synchronization period (PS). Variables TS, F, and FG were analyzed with PROC LOGISTIC, SAS, while ITC, IPC and PS were analyzed with the PROC GLM, option SAS. Variables TS, F, FG, ITC, IPC and PS were not affected by PR and NP. Cows predominantly Bos indicus in MAP < 70DPP had greater (P < 0.05) F and FG than those in MAP > 70DPP (F: 81.8 vs 43.7%; FG: 84.6 vs 45.5%). The TS was greater (P < 0.01) in cows treated during the rainy season than those treated during the dry season (96.4 vs 69.8%). During the rainy season, cows in MAP < 70DPP had greater (P < 0.01) F than did those in MAP > 70DPP (87.5 vs 42.1%, respectively). The PS was shorter (P < 0.01) during the dry season (36.9 h) vs the rainy season (48.8 h). The IPC was shorter (P < 0.01) in MAP < 70DPP (95.8 days) compared to MAP > 70DPP (148.3 days). In conclusion, days to EI insertion after parturition was the most important ...