Levels of estrogen and progesterone in milk of animals induced into lactation by reproductive steroids and thyrotropic releasing hormone
Agrawal, S.; Lakhchaura, B.D.; Atheya, U.K.; Dabas, Y.P.; Sud, S.C.; Mishra, D.P.
Indian Journal of Experimental Biology 31(6): 554-556
1993
ISSN/ISBN: 0019-5189 PMID: 8406603 Document Number: 410654
Cyclic, nonpregnant, non-lactating cattle were induced into lactation by s/c injections of estradiol 17-beta (0.1 mg/kg/day) plus progesterone (0.25 mg/kg/day) for 7 consecutive days, dexamethasone (20 mg/day) was administered on days 16-18 and thyrotropic releasing hormone (100 mu-g/day) on days 15, 22 and 29. Estradiol and progesterone levels were estimated in fat-free milk by RIA techniques. The milk of hormonally induced cattle had non-detectable levels ( lt 25 pg/ml) of estradiol while progesterone levels varied between 0.4 and 5.0 ng/ml. In contrast, the postpartum milk had 30-80 pg/ml of estradiol and 2-3 ng/ml of progesterone. The study, thus suggests that ovarian steroids used for induction of lactation are not excreted through the milk in any significant amount and consumption of such milk may not be a health hazard.