Ovarian follicular dynamics after cauterization of the dominant follicle in anestrous ewes

Martinez-Garcia, J.A.; Sánchez-Torres, María Teresa; Cordero, José Luis; Mendoza, G.D.; Garcia-Bojalil, C.M.; Garcia-Winder, M.

doi:10.1016/j.anireprosci.2005.12.018

Cited by 4 publications

(3 citation statements)

References 37 publications

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“…Os valores observados para a taxa de crescimento estão de acordo com os resultados obtidos no trabalho de Toosi et al (2010) em ovelhas (0,9 a 1,3 mm/dia). Martínez-García et al (2007) sugeriram que o aumento na taxa de crescimento em alguns folículos acontece depois da diminuição nas concentrações de progesterona no sangue.…”

Section: Resultsunclassified

Efeito do tempo da aplicação de prostaglandina na resposta folicular em ovelhas durante o ciclo estral

Uribe-Velásquez

Souza²,

Osório

2011

R. Bras. Zootec.

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RESUMO -Avaliou-se a resposta ovariana, usando ultrassonografia transretal, à aplicação de duas injeções de prostaglandina (PGF 2α ) em diferentes intervalos. Foram utilizadas 14 fêmeas ovinas da raça Bergamácia durante a estação reprodutiva, sendo que todas receberam uma dose intramuscular de um análogo de PGF 2α . As ovelhas foram distribuídas em dois grupos (n = 7). Em um dos grupos, a PGF 2α foi administrada sete dias (PG7) e, no outro, nove dias (PG9) depois da ovulação, quando o folículo dominante da onda 2 encontrava-se nas fases de crescimento e platô, respectivamente.Examinaram-se os ovários diariamente, utilizando-se um ultrassom Aloka 500, provido de um transdutor linear transretal de 7,5 MHz. A ultrassonografia foi iniciada um dia antes da segunda aplicação de prostaglandina até o dia 10 depois da ovulação em ambos os grupos. Amostras de sangue foram colhidas, via punção jugular, a cada dia, para quantificação de progesterona. As concentrações plasmáticas de progesterona mostraram-se menores no PG7 quando comparado com o PG9, imediatamente antes do tratamento com a PGF 2α (4,10 ± 0,17 vs 4,91 ± 0,29 ng/mL; respectivamente). A média do diâmetro máximo atingido pelo folículo dominante da onda 2 foi maior no grupo tratado PG7 comparado com o PG9 (5,5 ± 0,19 vs 4,29 ± 0,26 mm). Houve efeito do dia nos folículos totais. A quantidade de folículos pequenos (2-2,5 mm) foi maior (4,57 ± 0,78 versus 8,42 ± 1,36) no dia 6, nos grupos PG7 e PG9, respectivamente, mas não foram observadas mudanças nos folículos médios (3-3,5 mm) entre os grupos tratados. A proporção de folículos grandes (4 mm) aumentou depois da luteólise; os valores foram menores nas ovelhas tratadas no PG7 e mantiveram-se estáveis no tempo no PG9.Em ovelhas com rápida e completa luteólise, a ovulação ocorre no folículo dominante da onda 2 em fêmeas tratadas sete ou nove dias após a ovulação.Palavras-chave: folículo dominante, onda folicular, progesterona (P 4 ), sincronização, ultrassonografia Effect of time of prostaglandin administration on follicular response in ewes during oestrous cycleABSTRACT -The purpose of this study was to evaluate ovarian response, using transrectal ultrasonography, to two injections of Prostaglandin F 2α (PGF 2α ) given at different intervals. Fourteen Bergamasca ewes were injected with an i.m. dose of PGF 2α during the breeding season. Ewes were randomly alloted in two groups (n = 7) which received PGF 2α 7 d (PG7) or 9 d (PG9) after ovulation (when the dominant follicle of wave 2 was expected to be in the growth and plateau phase, respectively). Ovaries were examined daily with transrectal ultrasonography Aloka 500 with 7.5 MHz linear array transducer. Ultrasonography started 1 day prior to the second PG injection and ended 10 d after ovulation for both groups.Jugular vein blood samples were collected daily for progesterone assay. Plasma P 4 concentration was lower in PG7 than in PG9, immediately before PGF 2α treatment (4.10 ± 0.17 vs 4.91 ± 0.29 ng/mL, respectively). Mean maximum diameter size attained by the dom...

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Section: Resultsunclassified

Efeito do tempo da aplicação de prostaglandina na resposta folicular em ovelhas durante o ciclo estral

Uribe-Velásquez

Souza²,

Osório

2011

R. Bras. Zootec.

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“…Souza et al (2011) using a 10-day protocol with MAP, 0.5mL of cloprostenol (Prolise TM ), and 100 IU of eCG for every 10 kg of body weight, obtained an intermediate mean follicular growth rate of 1.35 ± 0.5 mm/day. Martínez-García et al (2007) suggested that increased growth rates in some follicles occur after progesterone concentrations decrease in the blood. Plasma progesterone levels in the present study were determined 7 days after ovulation.…”

Section: Discussionmentioning

confidence: 99%

Use of hormonal subdoses applied in Bai Hui acupuncture in estrus synchronization protocols for goats

Souza

Araújo

Biscarde

et al. 2019

SCA

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The objective of this study was to evaluate the efficacy of delivering reduced doses of hormones via the Bai Hui acupoint in estrus synchronization in goats. A total of 40 goats received intravaginal sponges with medroxyprogesterone acetate for 7 days. The goats were then randomly distributed into 5 treatment: T1 - application of 132.5 ?g of cloprostenol and 300 IU of equine chorionic gonadotropin (eCG), both by intramuscular injection (IM); T2 - application of 39.75 ?g cloprostenol at the Bai Hui acupoint, and 300 IU of eCG by IM; T3 - application of 132.5 ?g of cloprostenol by IM, and 90 IU of eCG at the Bai Hui acupoint; T4 - application of 39.75?g of cloprostenol and 90 UI of eCG, both in Bai Hui and T5 acupuncture: application of 39.75?g of cloprostenol and 90 UI of eCG, both applied in false acupoint. The goats were subjected to an estrus synchronization protocol and monitored for estrus detection, coverage and evaluation of reproductive parameters to detect entry into estrus. The data were subjected to normality tests, followed by appropriate statistical analyses of each variable. There was no significant difference (P > 0.05) in the percentage of animals in estrus (95.00 ± 11.18%), interval between sponge removal and beginning of estrus (49.72 ± 8.93 h), interval between sponge removal and end of estrus (76.84 ± 11.98 h), duration of estrus (27.08 ± 8.68 h), size of the largest follicle (6.82 ± 0.44 mm), interval between sponge removal and ovulation (78.28 ± 10.82 h), time from ovarian onset to estrus (28.52 ± 5.44 h), follicular growth rate (0.86 ± 0.29 mm/day), number of ovulations (1.32 ± 0.23), plasma progesterone concentration at 7 days after ovulation (10.28 ± 1.65 ng.mL-1), and gestation rate at 30 days after the beginning of estrus (75 ± 12.5%). However, the cost of the synchronization protocol per animal was 43.42% lower in treatments 4 and 5 (30% of the doses) than in treatment 1 (100% of the dose). Ovulation and estrus were efficiently synchronized with the use of 39.75 ?g of sodium cloprostenol and 90 UI of eCG, applied at the Bai Hui acupoint or at a false acupoint.

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“…Data from this study demonstrated that in mares even P4 blood concentrations maintained above 5ng/mL for four consecutive days were not capable of inhibited the dominant follicle, but these high P4 plasma levels also caused lower follicular growth rate. The growth rate of the ovulatory follicle, in non-E2 treated group from experiment 3, increased from 1.83 ± 0.15 to 2.98 ± 0.2 after the exogenous source of P4 was removed.Uribe-Velásquez et al (2008) reported that the growth inhibition of the dominant follicle possibly occurred because P4 exerts negative feedback on the hypothalamus and pituitary gland, resulting in release regulation of gonadotropins Martínez-García et al (2007). also suggest that the increase in growth rate in some follicles occurs after the decrease in blood P4 concentrations.During estrus, the dominant follicle develops and secretes E2.…”

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confidence: 99%

>b<Hormonal strategies for follicular atresia induction and stimulation of emergence of a new follicular wave in mares>/b<

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Ovarian follicular dynamics after cauterization of the dominant follicle in anestrous ewes

Cited by 4 publications

References 37 publications

Efeito do tempo da aplicação de prostaglandina na resposta folicular em ovelhas durante o ciclo estral

Efeito do tempo da aplicação de prostaglandina na resposta folicular em ovelhas durante o ciclo estral

Use of hormonal subdoses applied in Bai Hui acupuncture in estrus synchronization protocols for goats

>b<Hormonal strategies for follicular atresia induction and stimulation of emergence of a new follicular wave in mares>/b<

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