Effects of plasma progesterone concentrations on LH release and ovulation in beef cattle given GnRH

Colazo, M.G.; Kastelic, John P.; Davis, Hannah M.; Rutledge, M.; Martı́nez, M.F.; Small, J. A.; Mapletoft, R.J.

doi:10.1016/j.domaniend.2006.11.004

Cited by 85 publications

(69 citation statements)

References 36 publications

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“…These results indicated that CIDR insertion with GnRH treatment on day 0 probably does not affect intermediate ovulation induced by GnRH in heifers without functional CL on day 0, however CIDR tends to suppress intermediate ovulation in heifers with functional CL on day 0 together with existent CL. This may due to that high P 4 concentration from both CIDR and CL reduce GnRH-induced LH concentration and ovulatory responses [3]. In the present study, P 4 concentrations on day 7 in heifers with functional CL on day 0 in both CIDR-treated group and No-CIDRtreated group were tended to be higher than in heifers without functional CL on day 0.…”

Section: Discussionsupporting

confidence: 49%

Efficacy of Intravaginal Progesterone Administration as an Additional Treatment on Two Types of Timed AI Protocols in a Commercial Herd of Holstein Heifers

Iwakuma

Narahashi

Kitahara

et al. 2008

The Journal of Veterinary Medical Science

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ABSTRACT. Reproductive performance of two types of timed artificial insemination (TAI) protocols with or without intravaginal progesterone insert (CIDR) was investigated in a commercial herd of Holstein heifers. A total of seventy-four heifers with 14.4 months of age were allocated to two groups; Ovsynch (n=44) and estradiol benzoate (EB) used Heatsynch (EB-Heatsynch, n=30), and each group was additionally divided into two subgroups with CIDR insertion from day 0 to 7 (n=36) and without CIDR group (n=38). Blood was collected for progesterone (P 4 ) analysis and ovarian finding was monitored with ultrasonography. Heifers in CIDR-treated group resulted in higher pregnancy rate as compared to No-CIDR-treated group (63.9% vs 21.1%, P<0.01). Heifers with functional corpus luteum (CL) on day 0 resulted in significantly higher pregnancy rate in CIDR-treated group than No-CIDR-treated group (day 0: 67.9% vs 13.0%, P<0.01). CIDR insertion suppressed the intermediate ovulation during the first 7 days and the period from the second GnRH or EB administration to TAI as compared to No-CIDR-treated group (first 7 days: 33.3% vs. 52.6%; P<0.05, before TAI: 11.1% vs. 37.0%; P<0.05). In conclusion, the selected TAI protocols with CIDR provided acceptable pregnancy rate and contributed to the economical improvement by shortening the average age of first calving approximately for 2.5 months as compared to the previous management without TAI protocols.

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Section: Discussionsupporting

confidence: 49%

Efficacy of Intravaginal Progesterone Administration as an Additional Treatment on Two Types of Timed AI Protocols in a Commercial Herd of Holstein Heifers

Iwakuma

Narahashi

Kitahara

et al. 2008

The Journal of Veterinary Medical Science

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“…During low P 4 concentrations, LH pulsatility is enhanced, resulting in prematuration of oocytes. These oocytes can be fertilized but do not have development competence (22)(23)(24).…”

Section: Conception Ratementioning

confidence: 99%

Efficacy of repeatedly used CIDR device in cattle reproduction: a metaanalysisreview of progesterone concentration and conception rate

Chacher¹,

Çolak²,

Hayırlı³

2017

Turk J Vet Anim Sci

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In order to reduce estrus synchronization cost, utilization of residual progesterone (P 4 ) in the used controlled internal drug release (CIDR) device upon sanitization can be possible. Two datasets were compiled from 8 and 7 research articles involving 3434 (2653 heifers + 771 lactating cows + 10 ovariectomized cows) and 7301 cattle (3879 heifers + 3422 lactating cows) to evaluate blood P 4 concentration and conception rate, respectively, in response to repeatedly used CIDR devices after sanitization via autoclaving and disinfection. As the number of CIDR usages increased, blood P 4 concentration decreased linearly (y = -0.484X + 3.135, R 2 = 0.99, P < 0.001). Blood P4 concentration (1.52 vs. 2.20 ng/mL; P < 0.002) and conception rate (40.76 vs. 32.96%, P < 0.05) for lactating cows were lower than those for heifers. The sanitization method did not affect blood P4 concentration, but reused CIDR device subjected to disinfection was associated with reduced conception rate. In summary, depending upon the initial P4 load (1.38-1.90 g), the CIDR device could be used twice in lactating cows and four times in heifers after autoclaving to achieve target blood P4 concentrations.

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“…According to Sartori et al (2001), the asynchrony of follicular growth and the size of dominant follicles at the time of the LH peak are factors that determine the variation in reproductive responses to different protocols, similar to the results obtained in the present study. Colazo et al (2008) conducted a study designed to evaluate the response to GnRH in the induction of LH release under high levels of P 4 in both heifers and cows and observed that elevated levels of plasma P 4 reduced the release of LH by the pituitary gland after GnRH administration in both heifers and cows, in a linear fashion. The effects of GnRH administration at the time of insemination are connected to the uniform induction of a pre-ovulatory surge of LH and the anticipation of ovulation in cows with delayed ovulation (SÁ FILHO et al, 2011).…”

Section: Resultsmentioning

confidence: 99%

Administration of GnRH on the day of fixed-time artificial insemination (FTAI) and melengestrol acetate (MGA) administration after ftai in non-suckling nelore cattle

Silva¹,

Leão²,

Rodrigues³

et al. 2015

Sem. Ci. Agr.

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The present study evaluated the effect of administering buserelin acetate (GnRH) at the time of fixedtime artificial insemination (FTAI), along with the effect of oral administration of melengestrol acetate (MGA) after FTAI on conception rates in non-suckling Nelore cattle. In Experiment I, the effect of GnRH application at the time of FTAI was evaluated, as was administration of MGA from the 13 th through the 18 th day following FTAI (D24 to D29 after the initiation of the FTAI protocol). Experiment I was performed in 215 non-suckling cattle of the Nelore breed, divided into four experimental groups: Control group: 56 cows subjected to FTAI without GnRH injection; GnRH group: 51 cows subjected to GnRH at the time of FTAI; MGA Group: 57 cows subjected to FTAI without the application of GnRH with mineral supplementation and the addition of 2.28 g of MGA ® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol; MGA and GnRH group: 51 cows subjected to GnRH injection at the time of FTAI, with mineral supplementation and the addition of 2.28 g of MGA ® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol. In Experiment II, the effect of providing MGA five to ten days after FTAI was evaluated in 196 non-suckling pluriparous Nelore cows, divided into two groups: Control group: 104 cows subjected to FTAI, not supplemented with MGA; treated group: 92 cows supplemented with the addition of 2.28 g of MGA ® Premix per cow per day from D15 to D20 after the initiation of the FTAI protocol. Diagnosis of gestation was carried out 45 days after FTAI. Both experiments were conducted using a completely randomised design and analysed via the SAS MIXED procedure. In Experiment I, the control group displayed a lower conception rate (32.1%) compared with the groups administered GnRH, MGA, and both MGA and GnRH, which were respectively provided with MGA after FTAI (45.6%), GnRH at the time of FTAI (50.9%), and the combination of the two treatments (50.9%) (P<0.05). In Experiment II, the control group displayed a higher conception rate (40.38%) compared with the group receiving MGA post-FTAI (18.48%) (P<0.05). It was concluded that the injection of buserelin acetate (GnRH) at the time of FTAI and the oral administration of MGA ® Premix from the 13 th to the 18 th day after FTAI increased the conception rates in non-suckling Nelore cattle. However, when MGA ® Premix was administered orally from the fifth to tenth day post-FTAI, conception rates in non-suckling Nelore cattle were reduced.

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Effects of plasma progesterone concentrations on LH release and ovulation in beef cattle given GnRH

Cited by 85 publications

References 36 publications

Efficacy of Intravaginal Progesterone Administration as an Additional Treatment on Two Types of Timed AI Protocols in a Commercial Herd of Holstein Heifers

Efficacy of Intravaginal Progesterone Administration as an Additional Treatment on Two Types of Timed AI Protocols in a Commercial Herd of Holstein Heifers

Efficacy of repeatedly used CIDR device in cattle reproduction: a metaanalysisreview of progesterone concentration and conception rate

Administration of GnRH on the day of fixed-time artificial insemination (FTAI) and melengestrol acetate (MGA) administration after ftai in non-suckling nelore cattle

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