Abstract
This experiment has been carried out in order to examine the possibility of use of Euvestin sol (diethylstilbene+diethylstilbestrol) instead of Euvestin oil (diethylstilbene) for the convenience of practical application in the induction of lactation, fy investigating the levels of estrogen in the blood of goats treated with Euvestin sol or oil, and the relation between their levels and lactation results induced by Euvestin injection.
Animals used were five virgin goats, and among them, three were injected intramuscularly with Euvestin sol and the others were subcutaneously with Euvestin oil. Free and protein bound estrogen levels in the blood were measured by the mice intravaginal assay method. Milking was done once a day from the day of the first injection. As the lactation results, total milk yield, average daily yield, maximum period, duration of lactation and average butter fat percentage were measured.
The results obtained are summarized as follows:
( 1 ) Pretty remarkable differences were shown among free and protein bound estrogen levels in the blood at the time of the first injection. Thereafter, free estrogen levels increased and maintained in comparatively high levels about from 12th to 15th day and afterwards decreased, excepting D. Concerning to protein bound estrogen, no definite tendency was seen. Both free and protein bound estrogen levels on the 23rd day were lower than those at the time of first injection.
( 2 ) In either Euvestin sol or oil group, no relation was found between results of induced lactation and estrogen levels in the blood.
( 3 ) There was no difference in total milk yield and other characters, owing to the conditions and injection methods of Euvestin.
( 4 ) From the results of this experiment, the use of Euvestin sol for induced lactation seems to be plausible.
