1985 Volume 38 Issue 10 Pages 641-645
A progesterone releasing intravaginal device with an estradiol benzoate capsule (PRID) wasapplied to Holstein cows.
1) In 4 cows in postparturient anestrus PRID was inserted into the vagina for 12days and 25mg of prostaglandin F2α(PGF2α) was injected intramuscularly 24hours before the removal of PRID. All the cows, exceptone, showed standing estrus within 48hours after this removal. The estrous cows were inseminated artificiallyonce58hours after the removal and became conceived, except one.
2) In 8 cows showing an abnormal estrous cycle, PRID was inserted for 12days and superovulation treated with PMSG or FSH and PGF2α48hours before the removal of PRID. The mean numbers of ova collected and normal embryos per donor were 4.4 and 2.9, respectively, and 66% of ova collected from the donors with superovulation was judged as normal.
3) In 5 donor cows 1 to 4days after collection following the usual superovulation scheme (first) PRID was inserted for 14days. Superovulation was treated again with PMSG or FSH in combination with PGF2αtreatment 2days before the removal of PRID (second). The proportion of normal embryos was 65.5 and 40.0% in the first and second treatment, respectively.
In conclusion, the PRID treatment was effective for the recurrence of estrus in postpartum anestrus and for superovulation in cows showing an abnormal estrouscycle.
