Effect of GnRH Analogue, PMSG and Progesterone on Induction of Oestrus in Postpartum Anoestrus Jersey Crossbred Cows (Bos Taurus)

A study was conducted to evaluate the effect of GnRH analogue, PMSG and progesterone on induction of oestrus in postpartum oanestrous cattle bearing inactive ovaries. The animals were divided into four groups viz. group I, II, III and IV. Group I and II were treated with GnRH (Receptal 5ml) and PMSG (Folligon 500IU ). Group III animals were treated with Hydroxyprogesterone caproate (proluton depot 500 mg) in two occasions at 7 days interval. Group IV was treated with normal saline. The number of cows came into oestrus were 3/5(60.00%), 2/5(40.00%), 2/5(40.00%) and 1/5(20.00%) in group I, II, III and IV respectively. Onset of oestrus was 20.00±1.15, 10.00±1.00, 4.50±0.50 and 17.00 days. The size of the follicles attained on day of oestrus was 11.54±0.37, 12.70±0.60, 11.11±1.19 and 9.86 mm in group I, II, III and IV respectively. Results indicated that the postpartum anestrous cow could be brought into oestrus earlier with largest follicular size (12.70±0.60 mm).