Effect of human chorionic gonadotrophin on dominant follicles in cows: formation of accessory corpora lutea, progesterone production and pregnancy rates

Rajamahendran, R.; Sianangama, P.C.

doi:10.1530/jrf.0.0950577

Cited by 114 publications

(71 citation statements)

References 31 publications

(36 reference statements)

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“…However, only 54% of cows ovulate in response to GnRH given in mid-luteal phase (Vasconceles et al 1999) and the ovulatory capacity of the dominant follicle at this time may be dependent upon whether cows have two or three waves of folliclular growth. Treatment with human chorionic gonadotropin hormone 7 d after AI (Rajamahendran and Sianangama 1992) improved pregnancy rates in dairy cows. Post-AI treatment with GnRH is likely to be more effective on day 7 than day 14 because 96% of cows ovulate in response to GnRH given in the early (day 5 to day 9) luteal phase (Vasconceles et al 1999).…”

Section: Effects Of Day 14 Post-ai Gnrhmentioning

confidence: 95%

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The effects of gonadotrophin releasing hormone in prostaglandin F_2α-based timed insemination programs for beef cattle

Small¹,

Ambrose²,

McCaughey³

et al. 2001

Can. J. Anim. Sci.

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R. 2001. The effects of gonadotrophin releasing hormone in prostaglandin F 2α α -based timed insemination programs for beef cattle. Can. J. Anim. Sci. 81: 335-343. Trials were conducted in the spring (May; n = 324) and fall (October; n = 132) with crossbred continental-type beef cows assigned on the basis of parity and postpartum interval to one of three timed-AI treatments and one of two post-AI treatments. The timed-AI treatments were: (DPG) double (14 d apart) PGF 2α (Lutalyse ® ) and AI (day = 0) 72 h after the second PGF 2α (day -3); (OVS) Ovsynch ® with the second GnRH (Factrel ® ) at 48 h and AI at 66 h; and (BRC) the same as OVS except that the second GnRH was given at the time of AI. Half of the cows within each treatment were given GnRH on day 14. Plasma progesterone concentrations were determined for the day of the first injection and on days -3, 0, 14, and 21. Timed-AI pregnancy was diagnosed by ultrasonography at day 42 and confirmed at calving. For DPG, OVS and BRC, PGF 2α responder rates were 75.9, 51.4 and 71.3%, respectively, in spring (P < 0.05) and 70.4, 70.4 and 59.1% in fall (P > 0.05), and AI pregnancy rates were 28.7, 44.9 and 44.4% in spring (P < 0.05) and 25.0, 40.9 and 43.2% in fall (P > 0.05). Post-AI GnRH had no significant effect on pregnancy or conception rates or day 21 progesterone. The use of GnRH in the PGF 2α based timed-AI program improved pregnancy rates and the BRC treatment was as effective as OVS. Neither postpartum interval nor initial progesterone concentration influenced (P > 0.05) the effect of GnRH on AI pregnancy rate, and GnRH had no effect (P > 0.05) on twinning rate or gender ratio.

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Section: Effects Of Day 14 Post-ai Gnrhmentioning

confidence: 95%

“…Post-AI progesterone supplementation using progesterone-releasing devices (Savio et al 1993) or GnRH (Rettmer et al 1992) or human chorionic gonadotropin (Rajamahendran and Sianangama 1992) have been used to enhance luteal function. These treatments have been reported to either increase or have no effect on pregnancy rates.…”

mentioning

confidence: 99%

The effects of gonadotrophin releasing hormone in prostaglandin F_2α-based timed insemination programs for beef cattle

Small¹,

Ambrose²,

McCaughey³

et al. 2001

Can. J. Anim. Sci.

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“…However, circulating P4 remained lower, even after hCG treatment, in lactating cows compared with normally ovulating heifers. Eight studies that evaluated the effect of hCG on P4 concentrations from days 4 to 7 after AI in lactating dairy cows reported significant increases in circulating P4 concentrations after treatments with different doses of hCG: 3300 IU (Schmitt et al, 1996;Santos et al, 2001), 2500 IU (Stevenson et al, 2007b;Vasconcelos et al, 2011); 1500 IU (Walton et al, 1990;Hanlon et al, 2005; Kendall et al, 2009) or 1000 IU (Rajamahendran and Sianangama, 1992). Thus, treatment with hCG on day 5 after AI produces a consistent, fairly rapid (3 days delay) increase in circulating P4 in lactating dairy cows.…”

mentioning

confidence: 99%

Physiological and practical effects of progesterone on reproduction in dairy cattle

Wiltbank

Souza

Carvalho

et al. 2014

Animal

185

114

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The discovery of progesterone (P4) and elucidation of the mechanisms of P4 action have an important place in the history of endocrinology and reproduction. Circulating P4 concentration is determined by a balance between P4 production, primarily by the corpus luteum (CL), and P4 metabolism, primarily by the liver. The volume of luteal tissue and number and function of large luteal cells are primary factors determining P4 production. Rate of P4 metabolism is generally determined by liver blood flow and can be of critical importance in determining circulating P4 concentrations, particularly in dairy cattle. During timed artificial insemination (AI) protocols, elevations in P4 are achieved by increasing number of CL by creating accessory CL or by supplementation with exogenous P4. Dietary manipulations can also alter circulating P4, although practical methods to apply these techniques have not yet been reported. Elevating P4 before the timed AI generally decreases double ovulation and increases fertility to the timed AI. Near the time of AI, slight elevations in circulating P4, possibly due to inadequate luteal regression, can dramatically reduce fertility. After AI, circulating P4 is critical for embryo growth and establishment and maintenance of pregnancy. Many studies have attempted to improve fertility by elevating P4 after timed AI. Our recent meta-analysis and manipulative study indicated small fertility benefits (3% to 3.5%) mostly in primiparous cows. Thus, previous research has provided substantial insight into mechanisms regulating circulating P4 concentrations and actions. Understanding this prior research can focus future research on P4 manipulation to improve reproductive success. Keywords: progesterone, lactating dairy cows, fertility ImplicationsThis manuscript reviews effects of circulating progesterone (P4) on dairy cattle reproduction. Various methods to elevate P4 during growth of the preovulatory follicular wave have been shown to increase pregnancies/ artificial insemination (AI) and reduce double ovulation, providing methods to improve fertility and reduce twinning rate in lactating dairy cattle. Conversely, very low concentrations of P4 near AI are needed to optimize fertility. Finally, elevations of P4 after AI can impact embryonic development and also may elevate fertility. Thus, innovative strategies to optimize circulating P4 concentrations during selected reproductive periods enhance our management tools for improving reproductive efficiency of lactating dairy cows. Discovery of Progesterone (P4)The discovery of P4 begins with a clear description by Regnier deGraaf (1641-1673) of the corpus luteum (CL), calling them 'globules' and correctly surmising (for rabbits) that 'the number of globules equals the number of offspring from a particular mating ' (deGraaf, 1672 in (Jocelyn andSetchell, 1972)). A key discovery came in the laboratory of Gustav Born , an excellent histologist, who observed that the CL was a ductless gland and correctly advanced the idea that it was a gland of internal sec...

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“…In contrast, treatments of dairy cows at AI with hCG failed to stimulate conception rates under field conditions [69,70].…”

Section: Preventive Pharmaceutical Treatment At Aimentioning

confidence: 85%

Recent Possibilities for the Diagnosis and Pharmacological Control of Pregnancy Loss in Dairy Cow

Szenci¹

2015

JLS

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Abstract:One of the most recent techniques for the diagnosis of EP (early pregnancy) in cattle on the farm is B-mode ultrasonography. Under field conditions, acceptable results may be achieved with ultrasonography from days 25 to 30 post-AI. The reliability of the test greatly depends on the frequency of the transducer used, the skill of the examiner, the criterion used for a positive PD (pregnancy diagnosis) and the position of the uterus in the pelvic inlet. Pregnancy protein assays (PAG, PSPB) may provide an alternative method to ultrasonography for determining EP or LEM/EFM (late embryonic/early foetal mortality) in the cow. Although early pregnancy factor is the earliest specific indicator for fertilization, its detection is entirely dependend on the use of the RIT (rosette inhibition test), therefore its use in the field needs further inventions. Preventive pharmaceutical treatments with hCG (human chorionic gonadotropin), GnRH (gonadotropin realising hormone), PRID (progesterone-releasing intravaginal device) or CIDR (controlled internal drug release) inserts at different time periods at or post-AI may have some benefit in decreasing PL (pregnancy loss), however further examinations are warranted to determine how and when these treatments may influence PL in the field.

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Effect of human chorionic gonadotrophin on dominant follicles in cows: formation of accessory corpora lutea, progesterone production and pregnancy rates

Cited by 114 publications

References 31 publications

The effects of gonadotrophin releasing hormone in prostaglandin F_2α-based timed insemination programs for beef cattle

The effects of gonadotrophin releasing hormone in prostaglandin F_2α-based timed insemination programs for beef cattle

Physiological and practical effects of progesterone on reproduction in dairy cattle

Recent Possibilities for the Diagnosis and Pharmacological Control of Pregnancy Loss in Dairy Cow

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Effect of human chorionic gonadotrophin on dominant follicles in cows: formation of accessory corpora lutea, progesterone production and pregnancy rates

Cited by 114 publications

References 31 publications

The effects of gonadotrophin releasing hormone in prostaglandin F2α-based timed insemination programs for beef cattle

The effects of gonadotrophin releasing hormone in prostaglandin F2α-based timed insemination programs for beef cattle

Physiological and practical effects of progesterone on reproduction in dairy cattle

Recent Possibilities for the Diagnosis and Pharmacological Control of Pregnancy Loss in Dairy Cow

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Product

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The effects of gonadotrophin releasing hormone in prostaglandin F_2α-based timed insemination programs for beef cattle

The effects of gonadotrophin releasing hormone in prostaglandin F_2α-based timed insemination programs for beef cattle