Effect of uterine ecbolic drugs on progesterone level in postpartum normally calved cows

Normally calved 36 pluriparous cows divided into four experimental groups I, II, III and IV (control) and on day two postpartum, they were treated with of 25 mg PGF2α, 50 IU oxytocin, 5 mg methylergometrine maleate and 5 ml normal saline, I/M respectively. All the groups were inserted with Controlled Internal Drug Release Device (CIDR) on day 45–55 postpartum. In all the groups, significant elevation of serum progesterone was noticed from day 2 to day 30 postpartum followed by a drastic reduction on the day of induced oestrum and a sharp rise on day 10 post AI in pregnant and non-pregnant cows.