When using hormonal treatments to stimulate animal reproduction, it is of interest to
identify possible hormone residues in milk. Progesterone levels were herein determined in
the milk of CIDR-treated goats. A total of 18 animals were synchronized with prostaglandin;
once in estrus, they were treated with the vaginal CIDR device for a period of 15 days
(CIDR group, n = 9) or left untreated (control, n = 9). A third group of pregnant goats (90–120
days of pregnancy, n = 9) was used to compare milk progesterone values under different
physiological conditions. Progesterone levels were determined in a daily sample of milk
taken for 15 days after estrus from both the CIDR and control groups, and for 8 days from
pregnant goats. Mean milk progesterone levels in the CIDR group were not higher than
in controls or pregnant animals (P > 0.05). Total amount of milk progesterone showed no
significant differences between groups (P > 0.05). In conclusion, milk progesterone levels
of CIDR-treated goats did not exceed those of dioestrous or pregnant animals. Assuming
that progesterone levels in milk of naturally cycling or pregnant animals are safe for human
consumption, then the milk of CIDR-treated goats should also be safe.
© 2012 Elsevier B.V. All rights reserved.