Induction of abortion and parturition with corticosteroids in dairy cattle
1977 Volume 23 Issue 3 Pages 85-92
Details
1977 Volume 23 Issue 3 Pages 85-92
Induction of abortion or parturition by glucocorticoid injection was investigated with 54 Holstein Friesians and one Shorthorn, which were raised in the Nemuro, Kushiro and Tokachi areas of Hokkaido. These were divided into four groups. In group I, there were 5 cows and one heifer at 60135 days of pregnancy; in group II, 13, heifers at 165240 days; in group III, 10 cows and one heifer at 250275 days, and in group IV, 21 cows and 4 heifers at 277338 days of pregnancy. To each cow or heifer, 10 to 20 mg dose of glucocorticoids (Dexamethasone or Betamethasone) was given intramuscularly 1 to 3 times, coupled with an injection of estriol 12.5 to 50 mg. Out of the 25 cases in group IV, 22 had abnormal fetuses, which seemed to have been induced by the maternal ingestion of Veratrum grandiflorum Loes. fil.
Jugular vein blood was collected from each of 3 cows in group III, 6 cows in group IV, and 8 cows in the control. The serum was subjected to radioimmunoassay for the determination of steroid hormones. Six cows were selected for analysis of milk production and twelve for reproductive efficiency from the treated groups and examined against the controls at the Dairy Farm at Obihiro University.
Results obtained were summarized as follows:
1. Parturitions or abortions were induced in all cows except 3 in group I, but retained placentae were observed in 67.3% of these cases.
2. With regard to serum steroid hormones around parturition, the only difference observed was that in group IV, serum estrogen concentration before parturition was characteristically lower than that of the other two groups.
3. In 6 cows of group III, the average milk yield after induced parturition was 600 kg less than the former parturition. However, the milk yields after the following parturition showed no appreciable change.
4. Reproductive efficiency did not show any observable change in cows after the induced parturition as compared with that of cows having norma parturition.
The present report indicates that abortion or parturition can be induced almost completely from 150 days to late pregnancy with one to three injections of 10 to 20 mg of glucocorticoids. With the exception of the high occurrence of retained placentae, there was no ill effect, but a little effect was found on either milk production in the succeeding lactation or on reproductive efficiency concerning the following cycle recurrence.
