Medroxyprogesterone priming and response to the ram effect in Corriedale ewes during the nonbreeding season

Ungerfeld, Rodolfo; Suárez, Gonzalo; Carbajal, B.; Silva, Leticia; Laca, Mariana; Forsberg, M.; Rubianes, E.

doi:10.1016/s0093-691x(02)01302-x

Cited by 39 publications

(14 citation statements)

References 19 publications

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“…We have observed similar outcomes in a previous experiment done under laboratory conditions [5], but we obtained different results when the ewes from the same flock were stimulated under field conditions in the same anestrous period (Exps. 1 and 2 from [28]). Sheep show a stress response after transportation [29], and during adaptation to a new environment [30].…”

Section: Discussionmentioning

confidence: 97%

Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17?

Ungerfeld

Dago

Rubianes³

et al. 2004

Reprod. Nutr. Dev.

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-Anestrous ewes respond to the introduction of rams with either an ovulation within 2-3 days that may be followed by luteal phases of normal or short length, with delayed ovulations (5-6 days later), or with the luteinization of follicles. The aim of this work was to study the relationship between the growth status of the largest follicle present when rams are introduced and the type of ovarian response in non-treated ewes and in ewes treated with estradiol-17β before ram introduction. Thirteen anestrous Corriedale ewes were divided into 2 groups: E2 (n = 7) and C (n = 6). The E2 ewes received a single dose of 50 µg estradiol-17β 5 days before the introduction of the rams to synchronize the onset of their follicle waves, while C ewes remained untreated. When the rams were introduced, all E2 ewes had the largest follicle in a growing stage in contrast with the C ewes (3 out of 6; P < 0.05). Five C and 4 E2 ewes ovulated after the introduction of the rams (Day 3.4 ± 0.4 for C vs. 4.8 ± 0.3 for E2 ewes, respectively, P < 0.05). Only one ewe from each group developed a normal luteal phase; 4 C and 3 E2 ewes had short luteal phases. One C ewe and 2 E2 ewes had short luteal phases originating from follicles that did not ovulate. After the first luteal phase, all ewes returned to anestrus without a second ovulation or luteal phase. The remaining E2 ewe did not ovulate or show any changes in progesterone serum concentrations. We conclude that the growth status of the largest follicle alone does not determine the ovarian responding pattern of anestrous ewes to the ram effect. follicular dynamics / ultrasound / ram stimulus / ovulation / non-breeding season

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Section: Discussionmentioning

confidence: 97%

Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17?

Ungerfeld

Dago

Rubianes³

et al. 2004

Reprod. Nutr. Dev.

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“…Furthermore, short ovarian cycles result in scattered lambing because estrouses occur 18-21 and 24-27 days after introduction of rams. A pretreatment with 20 mg of progesterone (P4) on the day of ram introduction or 3 d before prevents short cycles, so that the first silent ovulation is followed by a normal cycle, with a single peak of estrus 18-21 days after the introduction of rams [6][7][8][9][10]. Estrus behaviour occurs at the first induced ovulation if ewes are treated with progestagen, such as fluorogestone acetate (FGA), using subcutaneous implants or intravaginal sponges [6,11].…”

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confidence: 99%

Progesterone Plus PMSG Priming in Seasonally Anovulatory Lactating Sarda Ewes Exposed to the Ram Effect

Todini

Malfatti

Barbato

et al. 2007

Journal of Reproduction and Development

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Abstract. The aim of this trial was to evaluate the effectiveness (fertility and lambing) of priming with a single injection of progesterone plus PMSG in anovulatory lactating Sarda ewes subjected to the ram effect (RE) in spring. Thirty ewes (P4 group) were i.m. injected with 30 mg progesterone and 500 IU PMSG 36 h before ram introduction (d 0). This treatment was compared to a 12-day treatment with fluorogestone acetate intravaginal sponges that was followed by injections of 350 IU PMSG upon sponge withdrawal (FGA group, n=30). All ewes responded to RE, showing plasma progestrone concentrations >1 ng/mL between d 6 and 12 (FGA) or 6 and 9 (P4). Eighty-nine percent of the P4 ewes conceived at first ovulation, and 11% conceived following a short estrus cycle. Lambings occurred on d 150.4 ± 3.9, and the lambing rate was 100%. The fertility of the FGA ewes was 83% for the induced ovulation and was 7% for the second ovulation after a normal cycle. The FGA ewes lambed on d 149.8 ± 4.4, and the lambing rate was 83%. Two abortions were recorded for the FGA ewes, which had higher prolificacy than the P4 group (2.2 ± 0.8 vs. 1.8 ± 0.4, respectively; P<0.05). Both fertility and the lambing rate were high in both groups, with a high degree of estrus synchronization, and there were no significant differences between the groups. We concluded that priming of lactating Sarda ewes in spring with P4+PMSG before RE is an effective and competitive method (cheaper and more practical than FGA+PMSG) of inducing fertile ovulations in these ewes. Key words: Estrus induction, Fertility, Progesterone priming, Prolificacy, Sheep (J. Reprod. Dev. 53: [437][438][439][440][441] 2007) h e " r a m e f f e c t " ( R E ) i s a n a t u r a l a n d i n e x p e n s i v e m e t h o d f o r c o n t r o l o f t h e reproductive activity in sheep [1]. The sudden introduction of rams to seasonally anovulatory ewes induces ovulations without estrus within 2 to 4 days. This silent ovulation is followed by either an ovarian cycle of normal duration (16-17 days) and a second ovulation associated with estrus behaviour or by an ovarian cycle of short duration (6 days) followed by a second silent ovulation. In this latter case, ovulation and estrus occur after a cycle of normal duration [2,3]. With "deep" anoestrous the percentage of short cycles is high, and anoestrus can follow the induced ovulations. The "depth" of anoestrus for a given flock in a given period could be measured as the percentage of females spontaneously ovulating, and it determines a wide range of variations in female responsiveness to RE [4]. RE is very effective in the Merinos and Mediterranean breeds of ewes, which show a shorter anoestrus period that is less deep

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“…Las hembras escogidas, para utilizar en ambas fases del proyecto, fueron ovejas de pelo, cruces de diversas razas, dado que, en Costa Rica, no se contaba con suficientes animales puros en el momento experimental. Además, cumplían con los requisitos de inclusión: Condición corporal entre 2,5 y 3,5 (Thompson & Meyer 1994;Scott 2007); no preñadas, con al menos un parto (Espinoza et al 2003;Ungerfeld et al 2003) y sin anormalidades uterinas ecográficamente detectables. Se excluyó las hembras en lactancia, debido al riesgo de estar en anestro o presentarlo posteriormente.…”

Section: Animalesunclassified

“…Se introdujo un hilo de algodón para extraerlas (Fukui et al 1987;Espinoza et al 2003). Las esponjas se desinfectaron con etanol al 90%; se dejaron secar en cámara de flujo laminar; luego se impregnó la superficie con 60 mg de MAP (Laboratorios Afford, obtenidos de Laboratorios Calox, Costa Rica) (Fukui et al 1999;Zarwaki 2001;Ungerfeld et al 2003;Barrett et al 2004;Catalano et al 2005;Catalano et al 2007;Santos et al 2010); diluidos en 1 mL de etanol al 90%; dispersando el fármaco, en forma lineal, sobre la superficie (Robinson et al 1968). Posteriormente, se secaron, en una cámara de flujo laminar con protección de la luz solar.…”

Section: Preparación De Las Esponjasunclassified

“…La técnica de sincronización más aceptada, a nivel mundial, en esta especie, incluye el uso de esponjas impregnadas con progestágenos para uso intravaginal, con o sin la adición de otras hormonas, tales como prostaglandinas y sus análogos y gonadotropina coriónica equina (eCG) (Robinson et al 1968;Fukui et al 1987;Fukui et al 1999;Simonetti et al 2000;Zarwaki et al 2001;Espinoza et al 2003;Ungerfeld et al 2003;Barret et al 2004;Wulster-Radcliffe et al 2004;Catalano et al 2005;Dogan & Nur 2006;Catalano et al 2007;Martínez-Tinajero et al 2007;Hernández-Olivos 2010;. Según los autores citados, el progestágeno más utilizado es la medroxiprogesterona acetato (MAP).…”

Section: Introductionunclassified

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Medroxiprogesterona acetato para la elaboración de dispositivos intravaginales caseros usados en la sincronización del estro en ovinos de pelo: Evaluación de su eficacia, sus efectos secundarios y comparación con un dispositivo comercial en hatos de Costa Rica.

González

Luna-Tortós²

2017

Ciencias Veterinarias

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Medroxiprogesterona acetato para la elaboración de dispositivos intravaginales caseros usados en la sincronización del estro en ovinos de pelo: Evaluación de su eficacia, sus efectos secundarios y comparación con un dispositivo comercial en hatos de Costa Rica. Resumen El objetivo del trabajo fue determinar la eficacia farmacológica y los efectos secundarios de un dispositivo intravaginal de fabricación casera elaborado con acetato de medroxiprogestrona para la sincronización del estro en ovinos de pelo. Se incluyeron un total de 78 hembras adultas, multíparas y ciclando en un estudio de dos etapas. En la primera etapa se utilizaron 18 animales con el objetivo de analizar la eficacia y los efectos secundarios del dispositivo de elaboración casera. En la segunda etapa se utilizaron 60 hembras divididas aleatoriamente en dos grupos: (G1) dispositivo casero (n-30), (G2) dispositivo comercial (n-30). El fin de esta etapa fue comparar la tasa de sincronización de celos y la tasa de concepción por monta natural. Para la sincronización se colocó el dispositivo con 60mg de acetato de medroxiprogesterona durante 12 días, con inyección de 200 UI de eCG y 5 mg de dinoprost trometamina al retirar del dispositivo. Se evaluaron andrológicamente 13 machos, de los cuales 4 fueron descartados por ser insatisfactorios y se utilizaron 8 machos satisfactorios durante ambas fases del estudio. En ambas etapas la presentación de celo fue nula durante la presencia del dispositivo y 100% presentaron celo 48 horas después de su retiro. Los efectos adversos en la primera etapa fueron: Vaginitis leve al día 12 en todas las hembras, 3 presentaron adherencias, 2 hembras con aumento de fibrinógeno el día 12 y una disminución general de los leucocitos. En la segunda etapa no hubo diferencias en la sincronización entre los grupos, la tasa de concepción fue de 80,0% y 76,7% en G1 y G2, respectivamente. Basado en los resultados de este trabajo, el dispositivo intravaginal de fabricación casera es efectivo para la sincronización del estro en ovinos de pelo y para la obtención de altas tasas de preñez por monta natural.Palabras clave: Sincronización del estro, ovinos, medroxiprogesterona acetato. AbstractThe goal of our study was to determine the pharmacological efficacy and adverse effects of a homemade intravaginal device containing medroxyprogesterone acetate for estrus synchronization in hair ewes. A total of

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Medroxyprogesterone priming and response to the ram effect in Corriedale ewes during the nonbreeding season

Cited by 39 publications

References 19 publications

Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17?

Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17?

Progesterone Plus PMSG Priming in Seasonally Anovulatory Lactating Sarda Ewes Exposed to the Ram Effect

Medroxiprogesterona acetato para la elaboración de dispositivos intravaginales caseros usados en la sincronización del estro en ovinos de pelo: Evaluación de su eficacia, sus efectos secundarios y comparación con un dispositivo comercial en hatos de Costa Rica.

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