Effects of FGA and PMSG on follicular growth and LH secretion in Suffolk ewes

Noël, B; Bister, Jean‐Loup; Pierquin, B; Paquay, R.

doi:10.1016/0093-691x(94)90181-h

Cited by 55 publications

(26 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This observation is surprising because the ewes treated with progestagens also received 500 IU eCG at sponge removal. Treatment with eCG is known to enhance the recruitment of small follicles [28], to improve the synchrony of estrus [29,30], to increase ovulation rates during the breeding season [28,29,31], and to enable the induction of estrous activity during the anovulatory season [32]. In this study, lambing rates (1.8-1.9) and litter sizes (1.9-2.0) were higher than those reported in previous investigations (0.7-1.1 and 1.1-1.7, respectively) [20,27,33].…”

Section: Discussionmentioning

confidence: 99%

Reproductive performance of Lacaune dairy sheep exposed to artificial long days followed by natural photoperiod without and with additional progestagen treatment during the nonbreeding season

et al. 2015

View full text Add to dashboard Cite

This study compared the reproductive performance of Lacaune dairy ewes exposed to a light program and subsequent male introduction without (n = 36) or with (n = 36) an additional 6-day progestagen treatment during the nonbreeding season. All ewes were exposed to extended day length (16 hours light and 8 hours darkness) for 77 days during winter (December 15 until March 2) followed by increasing natural photoperiod. At the end of the photoperiodic treatment, three blood samples were collected 6 days apart for progesterone (P4) analysis to determine cyclic activity. One half of the ewes were additionally subjected to a 6-day progestagen treatment in combination with PGF2 and eCG at insert withdrawal. Rams fitted with marking harnesses were introduced to females for 45 days and marked ewes recorded. Ewes exposed to the light program only were joined 40 days after the end of photoperiodic treatment, and ewes with additional progestagen treatment were joined 1 day after insert removal (40-44 days after the end of photostimulation). Lambing data were recorded and fertility (percentage of ewes lambing, lambing rate, and litter size) assessed to the first service period and overall. Mean serum P4 concentrations were similarly (P > 0.05) low in both groups (0.4-0.7 ng/mL vs. 0.4-0.6 ng/mL). On the basis of elevated P4 levels (>1 ng/mL), evidence of luteal activity was found in 27.8% of the ewes at the end of the light program. Estrus response was equally high (97.2%) and estrus distribution highly synchronized in progestagen-treated ewes (91.7% within 4 days). In ewes exposed to the light program only, estrous activity was recorded within 4 days (six ewes), from Day 8 to Day 17 (17 ewes) and from Day 19 to Day 25 (12 ewes) after joining. The percentage of ewes that lambed to the first service period was higher (P < 0.05) in ewes exposed to the light program only than that in the group additionally treated with progestagen/PGF2 /eCG (94.4% vs. 69.4%). Overall, the percentage of lambing ewes was similar in both groups (97.2% and 94.4%), and lambing rates (1.4-1.9) and litter sizes (1.9-2.1) were high and not influenced (P > 0.05) by the treatment. In conclusion, this study reports that exposition of Lacaune ewes to artificial long days followed by natural day length and male introduction is highly effective to induce fertile estrous activity during the nonbreeding season and offers a reliable and practical alternative to hormonal manipulation for out-of-season breeding in sheep. a b s t r a c tThis study compared the reproductive performance of Lacaune dairy ewes exposed to a light program and subsequent male introduction without (n ¼ 36) or with (n ¼ 36) an additional 6-day progestagen treatment during the nonbreeding season. All ewes were exposed to extended day length (16 hours light and 8 hours darkness) for 77 days during winter (December 15 until March 2) followed by increasing natural photoperiod. At the end of the photoperiodic treatment, three blood samples were collected 6 days apart for progesterone (...

show abstract

Section: Discussionmentioning

confidence: 99%

Reproductive performance of Lacaune dairy sheep exposed to artificial long days followed by natural photoperiod without and with additional progestagen treatment during the nonbreeding season

et al. 2015

View full text Add to dashboard Cite

show abstract

“…However, also the White Alpine Sheep kept in flocks B and C had a greater litter size than reported in earlier studies. In the present study, eCG was used to enhance the recruitment of small follicles (Noel et al, 1994), increase ovulation rates (Boland et al, 1981;Noel et al;, Leyva et al, 1998a and improve the synchrony of estrus (Boland et al, 1981;Cline et al, 2001) and may be the reason for the high prolificacy observed to the first service period. P4 concentrations were determined at insert application to confirm cyclicity, at insert removal to detect subluteal progesterone values in ewes treated with Eazi-breed™ CIDR ® G and 14 days later to verify ovulation.…”

Section: Discussionmentioning

confidence: 99%

Comparison of 6-day progestagen treatment with Chronogest® CR and Eazi-breed™ CIDR® G intravaginal inserts for estrus synchronization in cyclic ewes

Fleisch¹,

Werne²,

Heckendorn³

et al. 2012

Small Ruminant Research

View full text Add to dashboard Cite

The aim of this study was to compare the efficacy of two different short-term progestagen treatments for estrus synchronization in cyclic ewes. A total of 292 ewes of 3 flocks (A-C) on different farms were treated for 6 days with Eazi-breed™ CIDR® G (n = 145) or Chronogest® CR (n = 147) vaginal inserts in combination with 0.125 mg Cloprostenol and 300IU eCG at device removal. Blood samples were taken for progesterone (P4) determination at insert application and removal as well as 14 days later. One day after insert removal rams fitted with marking harnesses were joined to ewes for 35 days and marked ewes recorded daily. Lambing data were recorded and fertility to first service period and overall assessed. Results show that 24-96 h after insert removal 98.8% and 89.4% of the synchronized ewes in the flocks B and C were in estrus. Estrus response was not affected by the type of progestagen treatment and was lower (P < 0.05) in nulli-(82.1%) than in pluriparous (97.5%) ewes. Type of progestagen treatment did not affect fertility, but flock and parity influenced the percentage of ewes that lambed as well as the lambing rate. Overall more ewes (P < 0.001) lambed in flock A compared to flocks B and C (93.0 vs. 72.5 and 59.1%). In nulliparous animals the percentage of ewes that lambed was higher to the first service (P < 0.05) period but lower (P < 0.001) to the overall service period compared to pluriparous animals (51.5% vs. 49.3% and 64.7% vs. 84.2%). Lambing rates were higher in flock A than in flocks B and C to first service period and overall (1.3 ± 1.4, 0.9 ± 1.0, and 0.7 ± 1.0, P < 0.01 and 1.9 ± 1.1, 1.3 ± 0.9, and 1.0 ± 1.0, P < 0.001) and in nulliparous overall lower than in pluriparous ewes (1.1 ± 1.1 and 1.6 ± 1.1, P < 0.01). Serum P4 concentrations measured 14 days after insert removal were higher in the Chronogest® CR than in the Eazi-breed™ CIDR® G group (6.8 ± 4.1 ng/mL vs. 5.7 ± 3.3 ng/mL). Ewes of flock A had higher P4 values compared to ewes of flocks B and C (8.3 ± 4.1 ng/mL vs. 4.5 ± 1.5 ng/mL and 3.8 ± 1.7 ng/mL) and nulliparous lower P4 concentrations than pluriparous ewes (4.5 ± 2.2 ng/mL vs. 6.7 ± 4.0 ng/mL). In conclusion, a 6-day treatment with Chronogest® CR and Eazi-breed™ CIDR® G with prostaglandin and eCG at insert removal resulted in high estrus response and similar fertility in cyclic ewes. AbstractThe aim of this study was to compare the efficacy of two different short-term progestagen treatments for estrus synchronization in cyclic ewes. A total of 292 ewes 72.5 and 59.1%). In nulliparous animals the percentage of ewes that lambed was higher to the first service (P<0.05) period but lower (P<0.001) to the overall service period compared to pluriparous animals (51.5 vs. 49.3% and 64.7 vs. 84.2%).Lambing rates were higher in flock A than in flocks B and C to first service period and overall (1.3±1.4, 0.9±1.0, 0.7±1.0, P<0.01 and 1.9±1

show abstract

“…Os métodos mais utilizados para a indução e sincronização de estro e estimulação do crescimento folicular em ovelhas envolvem progesterona (P4) e/ou progestágenos e a administração intramuscular de eCG (gonadotrofina sérica de égua gestante). Entretanto, a primeira barreira é a diminuição na taxa de fertilidade, que está estreitamente relacionada com a grande variabilidade no tempo e no número de ovulações, sendo que parte dessa variação pode ser atribuída à quantidade total de folículos em crescimento presentes no ovário antes do tratamento (Noel et al, 1994).…”

Section: Introductionunclassified

“…Aplicando eCG no dia zero do ciclo estral em ovelhas (dia da ovulação), Noel et al (1994) constataram, por laparoscopia, que houve um aumento no recrutamento dos folículos pequenos e na taxa de ovulação. Comparando também a sincronização usando apenas eCG vs progestágenos por 14 dias mais a eCG em ovelhas, durante a estação reprodutiva, Evans & Robinson (1980) não encontraram efeitos significativos no desenvolvimento folicular total, corpo lúteo e as concentrações plasmáticas de P 4 e E 2 , observando também que a administração excessiva da eCG (800 a 1000 UI) resultou em luteinização prematura, devido aos efeitos luteinizantes da eCG, somados à grande quantidade de E 2 produzido pelos folículos grandes (> 5 mm), estimulando prematuramente a hipófise, com a conseqüente liberação de LH.…”

Section: Introductionunclassified

Respostas endócrinas e ovarianas associadas com o folículo dominante da primeira onda folicular em ovelhas sincronizadas com CIDR ou PGF2alfa

et al. 2002

View full text Add to dashboard Cite

RESUMO -Os efeitos de prostaglandina (PGF 2 a) vs CIDR e eCG (gonadotrofina coriônica eqüina) na dinâmica folicular da primeira onda e sua relação com as concentrações plasmáticas de P 4 e E 2 foram investigadas em ovelhas cíclicas. Foram utilizadas 14 fêmeas ovinas da raça Bergamascia; o Grupo 1 (G1) foi submetido a duas aplicações de PGF 2α e o Grupo 2 (G2), tratado com CIDR durante 14 dias, sendo que, no momento de sua retirada, administraram-se 500 UI de eCG. A dinâmica folicular ovariana foi monitorada por meio de ultrasom. Monitoraram-se todos os folículos ≥ 2mm e mapeou-se sua posição diariamente, observando-se o desenvolvimento individual de cada folículo. Desde o dia anterior à aplicação da segunda dose de PGF 2α (G1) e desde a administração de eCG (G2) até o décimo dia do ciclo estral, foram coletadas amostras de sangue para análise de P 4 e E 2 . Houve diferença significativa nas concentrações plasmáticas de P 4 e E 2 entre os tratamentos. A sincronização de estro e ovulação, utilizando CIDR + 500 UI de eCG, incrementou a quantidade de folículos recrutados, além de aumentar o diâmetro máximo e a taxa de crescimento dos folículos grandes na primeira onda folicular.Palavras-chave: dinâmica folicular, estradiol (E 2 ), ovinos, progesterona (P 4 ), ultra-sonografia Endocrine and Ovarian Response Associated with the First-Wave Follicle Dominant in Sheep Synchronized either CIDR or PGF 2αABSTRACT -The effect of prostaglandin (PGF 2 a) vs CIDR and eCG (equine chorionic gonadotrophin) on follicular dynamic of wave 1 and its relation with P 4 and E 2 plasma concentrations were investigated in cyclic ewes. Fourteen Bergamascia ewes were used, Group 1 (G1) synchronized by two i.m. injections of PGF 2α and Group 2 (G2) treated for 14 d with CIDR and 500 IU of eCG at dispositive withdrawal on day 14. Ovarian follicular dynamics were ultrasonically monitored. All the ovarian follicles ≥ 2 mm were measured, and their relative locations were recorded on an ovarian map in order to follow the sequential development of each individual follicle. Blood samples for P 4 and E 2 determination were collected daily from 1 d before the second injection of PGF 2α (G1) and administration of eCG (G2) until day 10 after ovulation of the cycle. There were significant differences in P 4 and E 2 plasma concentrations between treatments. The CIDR + eCG (500 IU) treatment enhanced the recruitment of smaller follicles and enhanced the maximum diameter and growth rate of large follicles during wave 1.

show abstract

Effects of FGA and PMSG on follicular growth and LH secretion in Suffolk ewes

Cited by 55 publications

References 27 publications

Reproductive performance of Lacaune dairy sheep exposed to artificial long days followed by natural photoperiod without and with additional progestagen treatment during the nonbreeding season

Reproductive performance of Lacaune dairy sheep exposed to artificial long days followed by natural photoperiod without and with additional progestagen treatment during the nonbreeding season

Comparison of 6-day progestagen treatment with Chronogest® CR and Eazi-breed™ CIDR® G intravaginal inserts for estrus synchronization in cyclic ewes

Respostas endócrinas e ovarianas associadas com o folículo dominante da primeira onda folicular em ovelhas sincronizadas com CIDR ou PGF2alfa

Contact Info

Product

Resources

About