Long term prostaglandin based-protocols improve the reproductive performance after timed artificial insemination in sheep

Fierro, S.; Viñoles, C.; Olivera-Muzante, J.

doi:10.1016/j.theriogenology.2016.11.031

Cited by 19 publications

(10 citation statements)

References 36 publications

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“…This has been strongly evidenced in the recent work of Fierro et al (2017) who concluded that long-term prostaglandin-based protocols with intervals between 12 and 16 days between the 2 injections enhance conception of ewes at cervical AI with fresh semen. For short intervals (7 days in this study), there is an altered progesterone profile during the luteal period preceding luteolysis which may depress the preovulatory events and the success of AI (Fierro et al 2017). As anticipated, the least conception rate was obtained with the single injection of PGF 2α .…”

Section: Discussionmentioning

confidence: 90%

“…When longer intervals between prostaglandin injections are applied, they result in longer periods of higher progesterone levels prior to mating, higher oestradiol plasma levels around the onset of estrus (Fierro et al 2016) and a higher fertilization rate (Fairnie et al 1977). This has been strongly evidenced in the recent work of Fierro et al (2017) who concluded that long-term prostaglandin-based protocols with intervals between 12 and 16 days between the 2 injections enhance conception of ewes at cervical AI with fresh semen. For short intervals (7 days in this study), there is an altered progesterone profile during the luteal period preceding luteolysis which may depress the preovulatory events and the success of AI (Fierro et al 2017).…”

Section: Discussionmentioning

confidence: 99%

“…The 2 inseminators randomly inseminated ewes in the 8 flocks irrespectively of the synchronization treatment. Ewes in all treatment groups were inseminated at 55 ± 1 h after the end of the hormonal treatment (Fierro et al 2017).…”

Section: Artificial Inseminationmentioning

confidence: 99%

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Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days

Besufkad

Betsha

Demis

et al. 2020

Journal of Applied Animal Research

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The study investigated, for fixed time artificially inseminated (AI) Menz ewes in field trials, the reproductive performance of prostaglandin-based treatments simultaneously to the standard 'P 4 +eCG' protocol. A total of 483 Menz ewes were assigned to either the 'P 4 +eCG' protocol, using progesterone impregnated intravaginal sponges in combination with equine chorionic gonadotropin (eCG) injection at sponge withdrawal, or the 'PGF s ' treatment where sheep received a single injection of prostaglandin or 'PGF 7 ' and 'PGF 11 ' where ewes were synchronized with 2 injections of prostaglandin 7 or 11 days apart, respectively. AI was implemented with fresh semen at 55 ± 1 h after the end of the hormonal treatment. Conception rate (CR; 60.87 ± 4.2) was highest for PGF 11 ewes (P < 0.05); PGF s ewes had the lowest CR (34.07 ± 4.1). Other factors did not affect variation in CR (P > 0.05). A higher proportion of ewes in the P 4 +eCG group yielded twins and triplets compared to the 3 prostaglandin-based protocols (P < 0.01). Nevertheless, a higher (P = 0.02) proportion (17.11 ± 4.3) of PGF 11 ewes yielded twins by comparison to their PGF 7 counterparts (2.50 ± 2.5). PGF-based protocol with 2 injections 11 days apart, preceded by a careful selection of non-pregnant ewes for cervical fixed-time AI, is a feasible reproductive management for sheep breeding programmes in Ethiopia.

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Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 99%

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Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days

Besufkad

Betsha

Demis

et al. 2020

Journal of Applied Animal Research

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“…Considering the production cost, prohibition on the use of castrated rams for estrus detection, and the full use of high-breeding-value rams, timed insemination is the optimal mating strategy ( 39 ). Combining previous research results and the data of ovulation time from CIDR measured in the three STH FecB genotype groups, it was recommended that fixed-time AI be performed between 48 and 60 h after CIDR removal ( 40 , 41 ).…”

Section: Discussionmentioning

confidence: 99%

Effects of FecB Mutation on Estrus, Ovulation, and Endocrine Characteristics in Small Tail Han Sheep

Wang

Guo

et al. 2021

Front. Vet. Sci.

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The Booroola fecundity gene (FecB) has a mutation that was found to increase the ovulation rate and litter size in Booroola Merino sheep. This mutation is also associated with the fecundity of small-tail han (STH) sheep, an important maternal breed used to produce hybrid offspring for mutton production in China. Previous research showed that the FecB gene affects reproduction in STH sheep, based on litter size records. However, the effects of this gene on estrus, ovulation, and endocrine characteristics in these sheep remain unclear. Here, we analyzed the traits mentioned earlier and compared them among the three FecB genotypes of STH ewes using estrus synchronization. Overall, 53 pluriparous ewes were selected from among 890 STH ewes and subjected to FecB genotyping for experiments to characterize estrous and ovulation rates. FecB heterozygous (+B) ewes presented an earlier onset of estrus (42.9 ± 2.2 h) and a shorter estrous cycle (17.2 ± 0.2 days) (P ≤ 0.05). The ovulation rates increased with the increasing copy number of the B allele (P ≤ 0.01). Ovulation time showed no significant differences among the three FecB genotypes. The serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone, estrogen (E2), and progesterone (P4) were measured in 19 of the ewes. Serum concentrations of E2 and FSH dramatically varied around the time of behavioral estrus. In FecB mutant homozygous (BB) ewes, E2 concentration had two peaks, which were higher (P ≤ 0.05) than those of ++ genotypes. FSH concentration of BB ewes was higher (P ≤ 0.05) than that of the ++ ewes just after estrus. The expression of the estrogen receptor 1 (ESR1) gene in the +B genotype was higher than in the other genotypes. Based on the data for the reproductive performance of STH ewes with the three FecB genotypes, our study suggests that the development of follicles in ewes with the B allele is dependent on the response to FSH regulated by E2 in the early stage. +B ewes, exhibiting moderate ovulation and litter size and a shorter estrous cycle, can be highly recommended in sheep crossbreeding systems for commercial mutton production. Moreover, this study provides useful information to conserve better and use the genetic resources of STH sheep in China.

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“…However, this assumption should be primarily evaluated in the future in a separate study. Prostaglandin F 2 α at 12 days, 14 days or 16 days interval improved the reproductive performances of Corriedale ewes at cervical timed artificial insemination using fresh semen (Fierro, Viñoles, & Olivera‐Muzante, 2017).…”

Section: Discussionmentioning

confidence: 99%

Relationships among the corpus luteum, follicles and conceptus in sheep

Ali

Derar

2020

Anat Histol Embryol

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This study aimed to investigate the intra‐ and interovarian relationships among the corpus luteum (CL), the largest follicle (LF) and follicular population in non‐pregnant and between the conceptus and ovarian structures in pregnant ewes. In experiment 1, the follicular and luteal structures were examined in 538 reproductive systems of non‐pregnant Awassi ewes. The follicular population was categorised into small (SF), medium (MF) and large (LF) groups. Inter‐relationships between CL and follicular population and between LF and subordinate follicles were determined. In experiment 2, the location and number of conceptuses were identified and correlated with the ovarian structures in 58 reproductive systems of pregnant ewes. Effects of pregnancy status, stage of pregnancy, pregnancy side and conceptual number on follicular population were determined. The results showed that the right ovary was more active than the left ovary. CL had intraovarian positive effect on the number of medium and large follicles. LF had no local suppressive effect on the subordinate follicles. Side and stage of pregnancy and the conceptual number did not affect the follicular population. Accordingly, it can be concluded that the LF has no local suppressive effect on the subordinate follicles. The CL has intraovarian positive effect on the follicular population. Follicular population does not show remarkable changes during the first term of pregnancy. The present study probably provides information which may help in the understanding of the ovarian dynamics during pregnancy in sheep.

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Long term prostaglandin based-protocols improve the reproductive performance after timed artificial insemination in sheep

Cited by 19 publications

References 36 publications

Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days

Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days

Effects of FecB Mutation on Estrus, Ovulation, and Endocrine Characteristics in Small Tail Han Sheep

Relationships among the corpus luteum, follicles and conceptus in sheep

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