Ovarian response after four continuous administrations of gonadotrophin in beef cattle.

Analysis relating to corpora lutea and two continuous administrations of PMSG in beef cattle.

Recent advances in the superovulation in cattle.

The variability in the superovulatory response continues to be one of the most frustrating problems with embryo transfer in cattle. The removal of LH from pituitary extracts has tended to reduce the variability in response, and several studies involving the use of the purified porcine pituitary extract. Folltropin-V are reviewed. The major source of variability in the superovulatory response in...

Effect of progesterone concentration and duration of proestrus on fertility in beef cattle after fixed-time artificial insemination.

The objective was to determine the effect of plasma progesterone concentration and the duration of proestrus during growth of the ovulatory follicle on fertility in beef cattle. Heifers (N = 61) and postpartum cows (N = 79) were assigned randomly to four groups in a two-by-two design involving luteal-phase versus subluteal-phase plasma progesterone concentrations and normal versus short proestr...

Effects of large follicle aspiration on superovulatory response of beef cows

The effects of large follicle aspiration before and during superovulation on the ovarian response of beef cows were investigated using a crossover design. The removal of the largest follicle before superstimulation without assessment of functional dominance by serial examination of follicle development did not improve ovarian response. Similarly, the removal of large follicles on 1 day or 3 day...

Cortisol and Postpartum Luteal Function in Cattle

The present study investigated serum cortisol in response to postpartum ovarian resumption and luteal function. Postpartum ovarian resumption was detected based on a rise in progesterone (P4) concentrations during three weeks after calving. Twenty two Holstein cows in a semi-closed dairy farm in Qena city, Egypt were used. The study was carried out from late March to early June; the period char...