title: Hormonal induction of lactation: estrogen and progesterone in milk.
abstract: Estrogen and progesterone in milk during the first 21 days of induced and postpartum lactation in Holstein cows and heifers were estimated by assay procedures. Lactation was induced with estradiol-17 beta and progesterone treatment for 7 days. Estrogen and progesterone in induced lactations differed from concentrations in postpartum lactations. In early lactation estrogen was higher in postpartum milk (521 +/- 103 pg/ml on day 1) than in induced milk (336 +/- 46 pg/ml on day 1), but after day 7 the reverse was true (192 +/- 33 pg/ml and 233 +/- 32 pg/ml on day 7). Progesterone remained higher in induced lactation through the first 21 days than in postpartum lactation with the exception of day 19. Progesterone in postpartum milk increased from 4 +/- 1 ng/ml on day 1 to 11 +/- 2 ng/ml on day 21. Progesterone in induced milk showed greater fluctuation (11 +/- 3 ng/ml on day 1 and 22 +/- 9 ng/ml on day 3) but gradually decreased to 12 +/- 2 ng/ml on day 21 (11 +/- 2 ng/ml on day 21 of postpartum lactation).
mesh_terms: D000818:Animals; D002417:Cattle; D004967:Estrogens / Q000032:analysis / Q000494:pharmacology*; D005260:Female; D007774:Lactation / Q000187:drug effects*; D008892:Milk / Q000032:analysis; D011247:Pregnancy; D011374:Progesterone / Q000032:analysis / Q000494:pharmacology*
chemical_list: D004967:Estrogens; D011374:Progesterone