Progesterone, estrogen, LH, FSH and PRL concentrations in plasma during the estrous cycle in goat

Progesterone, estrogen, LH, FSH and PRL variations in plasma were measured in 7 goats by RIA. Mean progesterone level was 0.0-0.8 ng/ml in estrus and 1-4 ng/ml in diestrus. Estrogen levels ranged from 10 to 20 pg/ml in diestrus; around estrus, a peak of 26.9 +/- 3.18 pg/ml was observed. LH values were 0.5-3.0 ng/ml with a preovulatory peak (40.7 +/- 10.12 ng/ml) 8 to 24 h after the onset of estrus. Except for a peak (14.0 +/- 3.09 ng/ml) coincident with LH surge, plasma FSH level ranged between 2 and 4 ng/ml. PRL level averaged 2-5 ng/ml in diestrus but high concentrations of this hormone were seen around estrus.