Follicular dynamics, estrous response and pregnancy rate following GnRH and progesterone priming with or without eCG during non-breeding season in anestrous Beetal goats

Hameed, Nasir; Khan, M. Islam; Ahmad, Waqas; Abbas, Mohamed S.; Murtaza, Ali; Shahzad, Muhammad; Ahmad, Nasim

doi:10.1016/j.smallrumres.2019.106026

Cited by 19 publications

(14 citation statements)

References 29 publications

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“…For breeding purposes, goats in standing oestrus were placed at random with one of six sexually active/fertile bucks with the goat to buck ratio being 1:7. Based on the findings of Hameed et al (2020), the mean interval of onset of oestrus after CIDR removal was 33.2 ± 2.0 and 57.0 ± 4.2 h in eCG and non-eCG-treated goats; therefore, the interval from CIDR removal to breeding was 72 h in the current experiment. The rationale for having 72 h breeding window (day −3 to 0) was to provide opportunity to all goats for the exhibition of oestrus and breeding in the presence of bucks.…”

Section: Experimental Design Oestrous Response and Natural Breedingmentioning

confidence: 67%

“…A sample size was calculated using the POWER procedure of SAS (SAS/STAT version 9.4; SAS Institute Inc.). The calculation was based on Hameed et al (2020), that administration of 400 IU of eCG was pre-ovulatory follicle (6.27 vs. 7.20 vs. 7.31 mm ± 0.07; p < .01) and corpora lutea (6.75 vs. 8.26 vs. 8.07 mm ± 0.42; p = .04) than CON. The mean follicular blood flow did not differ among treatments; however, the mean luteal blood flow was greater in L-eCGtreated goats (0.81 vs. 1.61 vs. 1.07 cm 2 ± 0.12; p = .001).…”

Section: Sample Size Calculationmentioning

confidence: 99%

“…The use of eCG has shown to be a more efficient strategy for induction of oestrus during LBS compared with GnRH (Robin et al, 1994;Santos-Jimenez et al, 2020); however, the information on optimizing the dose of eCG in LBS is still lacking in Beetal dairy goats. Hameed et al (2020) reported that administration of 400 IU of eCG improved the follicular dynamics, ovulation rate, plasma concentrations of P 4 and pregnancy rate in anestrous Beetal goats; nevertheless, the authors did not evaluate the effect of eCG on haemodynamics of ovarian structures, oestrous intensity and twinning and prolificacy rates.…”

Section: Introductionmentioning

confidence: 99%

“…The use of eCG has shown to be a more efficient strategy for induction of oestrus during LBS compared with GnRH (Robin et al, 1994; Santos‐Jimenez et al, 2020); however, the information on optimizing the dose of eCG in LBS is still lacking in Beetal dairy goats. Hameed et al (2020) reported that administration of 400 IU of eCG improved the follicular dynamics, ovulation rate, plasma concentrations of P 4 and pregnancy rate in anestrous Beetal goats; nevertheless, the authors did not evaluate the effect of eCG on haemodynamics of ovarian structures, oestrous intensity and twinning and prolificacy rates. Previous studies have reported that increased blood flow to ovarian structures is associated with larger pre‐ovulatory follicles and corpus luteum (CL) and high levels of steroid hormones resulting in an improvement in fertility in cattle (Abouelela et al, 2021; Caleb, 2017; Velho et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, characterization of the effects of eCG on ovarian haemodynamics and its potential impact on follicular development and luteal cell differentiation to synthesize P 4 would contribute to the mechanistic understanding of ovarian physiology during LBS in goats. It is known already that administration of eCG induces oestrus (Hameed et al, 2020); however, it is unclear if dose of eCG modulates the development of follicular and luteal tissue via enhanced perfusion of ovarian structures during LBS in acyclic Beetal goats.…”

Section: Introductionmentioning

confidence: 99%

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Effect of eCG dose on ovarian haemodynamics, hormonal profiles and prolificacy rate when oestrus was induced during low‐breeding season in Beetal goats

Sharif

Hassan

Arshad

et al. 2022

Reprod Domestic Animals

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The objectives of the experiment were to determine the effect of two doses of equine chorionic gonadotropin (eCG) in a standard synchronization protocol based on a short‐term progesterone (P4) priming on ovarian structures and haemodynamics, concentrations of steroid hormones and prolificacy rate when oestrus was induced during low‐breeding season (LBS) in Beetal dairy goats. We hypothesized that inclusion of eCG in a short‐term P4 priming‐based synchronization protocol would increase the blood perfusion to ovarian structures leading to enhance oestrous and ovulatory responses and prolificacy rate in goats. Forty‐two multiparous acyclic goats were blocked by body condition and, within block, assigned randomly to receive saline as control (CON), low eCG (L‐eCG; 300 IU) or high eCG (H‐eCG; 600 IU) dose. Initially, a controlled internal drug release (CIDR) device was placed in the anterior vagina on d −8, followed by removal of CIDR on d −3, concurrent with the administration of PGF2α and eCG according to their respective treatments. Goats were monitored for oestrous response. B‐mode and Doppler ultrasonography was performed with 12‐h interval, starting from day −3 until natural breeding (day 0), and then on days 5, 10, 15 and 20 post‐breeding to monitor follicular and luteal dynamics and blood flow, respectively. Blood was sampled at 0, 12, 24, 36 and 60 h after CIDR removal to quantify plasma concentrations of estradiol‐17β (E2), whereas plasma concentrations of P4 were assayed at days 5, 10, 15 and 20 after breeding. Pregnancy and prolificacy rates were determined at day 30 and 150 after breeding, respectively. Data were analysed with mixed‐effects models, and orthogonal contrasts were used to evaluate the effect of treatment [Con vs. (½ L‐eCG + ½ H‐eCG)] and dose of eCG (L‐eCG vs. H‐eCG). Data are presented in sequence as CON, L‐eCG, H‐eCG (LSM ± SEM). The oestrous intensity score (152.9 vs. 182.7 vs. 186.5 ± 15.1; p = .02) was greater in eCG‐treated goats as compared to CON. Administration of eCG reduced the intervals to standing oestrus (66.2 vs. 41.8 vs. 48.9 h ± 5.5; p = .05), breeding (70.2 vs. 44.4 vs. 45.4 h ± 4.5; p = .03) and ovulation (84.5 vs. 61.2 vs. 63.4 h ± 6.2; p = .05) compared with CON goats. The mean growth rate of pre‐ovulatory follicle was greater (1.11 vs. 1.49 vs. 1.45 mm ± 0.08; p = .01) in eCG‐treated goats resulting in an increased diameter of pre‐ovulatory follicle (6.27 vs. 7.20 vs. 7.31 mm ± 0.07; p < .01) and corpora lutea (6.75 vs. 8.26 vs. 8.07 mm ± 0.42; p = .04) than CON. The mean follicular blood flow did not differ among treatments; however, the mean luteal blood flow was greater in L‐eCG‐treated goats (0.81 vs. 1.61 vs. 1.07 cm2 ± 0.12; p = .001). The mean concentrations of E2 (4.03 vs. 5.21 vs. 4.78 pg/ml ± 0.42; p = .04) and P4 (4.85 vs. 6.39 vs. 6.22 ng/ml ± 0.34; p = .04) were greater in eCG‐treated goats. The twinning rate did not differ between treatments; nevertheless, prolificacy rate was greater (p = .04) in L‐eCG‐treated goats. Collectively, our data sugges...

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Section: Experimental Design Oestrous Response and Natural Breedingmentioning

confidence: 67%

Section: Sample Size Calculationmentioning

confidence: 99%