Pharmacological treatments to support luteal function and prevent precocious luteolysis

Administration of GnRH and hCG post insemination

Administration of hCG (4-6d after AI) and GnRH (11-12d after AI) are well established as methods to improve fertility in cattle herds, through prevention of early embryonic mortality.

Both treatments aim at elimination of the pro-luteolytic effect of oestradiol and benefit from the formation of additional corpora lutea and increased production of progesterone.

There are some differences in the timing of these two approaches:

Timing of the administration of GnRH and hCG post insemination
TreatmentFollicular turnoverLuteal function and P4 levelsResults - timing
hCG at 4-6d post AIPrevention of precocious luteolysis - elimination of early luteal phase follicles still growing  after AI.Increase in P4 levels thanks to the creation of accessory corpora lutea

Direct stimulation of CL function (LH effect)
The result measured as decrease of oestradiol levels and increase in progesterone levels approx. 6-7d post AI
GnRH at 11-12d post AIPrevention of precocious luteolysis - elimination of early luteal phase follicles still growing  after AI.Increase in P4 levels thanks to the creation of accessory corpora lutea
The result measured as decrease of oestradiol levels and increase in progesterone levels approx. 12-13d post AI

For more details see:

top

Supplementation of exogenous progesterone/progestagens

Administration of exogenous progesterone or progestagens to improve theluteal environment for the developing embryo have so far met with limited success.

Factors limiting success of the method are:

  • uncertainty about the best time to initiate the treatment
  • wide discrepancy of the recommended dose
  • administration route: majority of products available on the market are intravaginal devices

Reported results of the use of progesterone for early pregnancy maintenance

results on use of progestagens

top