Treatment with hCG 4 or 6 days after TAI to improve pregnancy outcomes in repeat-breeding dairy cows

Alnimer, Mufeed A.; Shamoun, Ahmad I.

doi:10.1016/j.anireprosci.2015.03.016

Cited by 10 publications

(10 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Embryonic loss was not different among the groups, similar to the results of Tefera et al (2001) who reported that promoting luteal function post AI had no effect on embryonic mortality in lactating dairy cows. However, our results conflict with the other studies focused on hCG administration on day 4/5 post AI that reported beneficial effects in both RB cows (Alnimer and Shamoun 2015) and lactating dairy cows (for only summer months, Fischer-Tenhagen et al 2010).…”

Section: Discussioncontrasting

confidence: 99%

“…Thus, supporting pregnancy by inducing endogenous progesterone source as early as possible may result in improved fertility. Likewise, studies evaluating hCG administration on day 4 post TAI are limited in both lactating dairy cows (Tefera et al 2001;Fischer-Tenhagen et al 2010) and RB (Alnimer and Shamoun 2015) cows. Thus, more knowledge is needed about the effect of earlier administration of hCG on day 4 post TAI on dairy cows' fertility.…”

mentioning

confidence: 99%

See 1 more Smart Citation

The ovulatory response to human chorionic gonadotropin administration on day 4 post timed artificial insemination improved fertility in repeat breeder cows

et al. 2021

View full text Add to dashboard Cite

This study focused on determining the success of inducing endogenous progesterone source (by formation of accessory corpus luteum) by human chorionic gonadotropin (hCG) administration on day 4 post timed artificial insemination (TAI) and on evaluating the effect of the day of hCG administration (day 4 or 5 post TAI) on pregnancy rates in repeat breeder cows according to their responses to hCG administrations. Non-pregnant cyclic lactating Holstein dairy cows with more than three services despite no clinical reproductive abnormalities were enrolled in the study. All cows (n = 192) received the Ovsynch protocol (GnRH-7d-PGF2α-56h-GnRH-16/18h-TAI) and hCG administration (1500 IU, i.m.) was performed in group hCG4 (n = 64) on day 4 and in group hCG5 (n = 68) on day 5 post TAI. The control group (CON, n = 60) did not receive any hCG treatment. The responses (ovulation rate) to hCG (~64%) were similar on days 4 and 5 post TAI. Pregnancy per AI (P/AI) at 31 days was similar among the groups (48.3% in CON, 48.4% in hCG4, and 42.6% in hCG5). Regardless of the day of the treatment (hCG4 + hCG5), the cows had an ovulatory response to hCG (54.1%), and a greater P/AI (P = 0.007) at 31 days than those without a response (29.8%). The administration of hCG on either day 4 or 5 post TAI did not increase overall pregnancy rates, however, the ovulatory response to the post TAI hCG administration on day 4 improved fertility in repeat breeder cows. Further studies are needed with a larger number of animals to reveal this potentiallly beneficial effect.

show abstract

Section: Discussioncontrasting

confidence: 99%

mentioning

confidence: 99%

The ovulatory response to human chorionic gonadotropin administration on day 4 post timed artificial insemination improved fertility in repeat breeder cows

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In a recent large study, Nascimento et al (2013a) reported a modest increase of 3% (metaanalysis study; n = 4,397 cows) or 3.5% (manipulative study; n = 2,979 cows) in pregnancy rate following hCG administration 5 d after AI. A beneficial effect on pregnancy per AI has been reported in repeat-breeding dairy cows treated with hCG 6 d after AI (Alnimer and Shamoun, 2015). An early increase in P4 has been associated with improved pregnancy rates in cattle; however, administration of hCG on d 5 to 7 does not affect circulating P4 for several days, partly due to the time required for ovulation and accessory CL formation (Rizos et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Effect of human chorionic gonadotrophin administration 2 days after insemination on progesterone concentration and pregnancy per artificial insemination in lactating dairy cows

Sánchez

Randi

Passaro

et al. 2018

Journal of Dairy Science

View full text Add to dashboard Cite

The aim of this study was to examine the effect of a single administration of human chorionic gonadotrophin (hCG) during the establishment of the corpus luteum (CL) on progesterone (P4) concentration and pregnancy per artificial insemination (P/AI) in lactating dairy cows. Postpartum spring-calving lactating dairy cows (n = 800; mean ± SD days in milk and parity were 78.5 ± 16.7 and 2.3 ± 0.8, respectively) on 3 farms were enrolled on the study. All cows underwent the same fixed-time AI (FTAI) protocol involving a 7-d progesterone-releasing intravaginal device with gonadotrophin-releasing hormone (GnRH) administration at device insertion, prostaglandin at device removal followed by GnRH 56 h later, and AI 16 h after the second GnRH injection. Cows were blocked on days postpartum, body condition score, and parity and randomly assigned to receive either 3,000 IU of hCG 2 d after FTAI or no further treatment (control). Blood samples were collected on d 7 and 14 postestrus by coccygeal venipuncture on a subset of 204 cows to measure serum P4 concentration, and pregnancy was diagnosed by ultrasonography approximately 30 and 70 d after FTAI. Administration of hCG caused an increase in circulating P4 concentrations compared with the control treatment on d 7 (+22.2%) and d 14 (+25.7%). The P/AI at 30 d after FTAI was affected by treatment, farm, body condition score, and calving to service interval. Overall, administration of hCG decreased P/AI (46.3% vs. 55.1% for the control). Among cows that did not become pregnant following AI, a greater proportion of control cows exhibited a short repeat interval (≤17 d) compared with cows treated with hCG (8.6% vs. 2.8%, respectively). In addition, the percentages of cows pregnant at d 21 (59.6% vs. 52.0%) and d 42 (78.3% vs. 71.9%) were greater in control than in hCG-treated cows. The overall incidence of embryo loss was 10.7% and was not affected by treatment. There was a tendency for an interaction between treatment and CL status at synchronization protocol initiation for both P4 concentration and P/AI. In conclusion, administration of hCG 2 d after FTAI increased circulating P4 concentrations. Unexpectedly, cows treated with hCG had lower fertility; however, this negative effect on fertility was manifested primarily in cows lacking a CL at the onset of the synchronization protocol.

show abstract

“…These hormones can also be used in combination with CIDR or PRID (Kendall et al 2009). It has been reported that hCG treatment on days 4, 5 or 6 in the cycle increased the blood progesterone concentrations and pregnancy rates (Kendall et al 2009;Alnimer and Shamoun 2015;Pandey et al 2016). In the present study, pregnancy rates numerically increased as a result of hCG alone or combined PRID.…”

Section: Discussionmentioning

confidence: 99%

Effect of progesterone, human chorionic gonadotropin and progesterone + human chorionic gonadotropin treatment on conception rates in repeat breeder cows

Alkan

Erdem

2020

Acta Vet. Brno

View full text Add to dashboard Cite

The aim of this study was to investigate the effects of hormonal support on the pregnancy rate in repeat breeder cows. Prostaglandin F2α + Ovsynch oestrus synchronization protocol was applied to the cows. Following the fixed time insemination (day 0), the cows were divided into 4 groups. In Group 1 (n = 42), progesterone releasing intravaginal device (PRID) was placed vaginally at 84 h and removed on the 9th day after the artificial insemination. In Group 2 (n = 40), the cows were administered human chorionic gonadotropin (hCG) on the 7th day. Group 3 (n = 45) was applied a combination of progesterone and hCG. Group 4 (n = 42) was not given any treatment. Blood samples were collected from all cows 4 times on days 3.5, 7, 12, and 18 to evaluate progesterone concentrations. The pregnancy rates were 40.47%, 37.50%, 44.44%, and 30.95% in Group 1, 2, 3, and 4, respectively (P > 0.05). In addition, in cows with progesterone concentrations <2 ng/ml on day 3.5, the pregnancy rates were found to be lower than in the cows with progesterone concentrations >2 ng/ml in Group 4 (P < 0.05). Progesterone supplementation in cows with progesterone concentrations < 2 ng/ml appeared to increase pregnancy rates (P < 0.05) in Groups 1 and 3. As a result, post-insemination hormonal applications in the repeat breeder cows did not increase the pregnancy rate. However, it was concluded that determination of progesterone concentrations on day 3.5 following artificial insemination and then hormonal support in the cows with low concentrations would increased the pregnancy rate.

show abstract

Treatment with hCG 4 or 6 days after TAI to improve pregnancy outcomes in repeat-breeding dairy cows

Cited by 10 publications

References 43 publications

The ovulatory response to human chorionic gonadotropin administration on day 4 post timed artificial insemination improved fertility in repeat breeder cows

The ovulatory response to human chorionic gonadotropin administration on day 4 post timed artificial insemination improved fertility in repeat breeder cows

Effect of human chorionic gonadotrophin administration 2 days after insemination on progesterone concentration and pregnancy per artificial insemination in lactating dairy cows

Effect of progesterone, human chorionic gonadotropin and progesterone + human chorionic gonadotropin treatment on conception rates in repeat breeder cows

Contact Info

Product

Resources

About