Effect of crestar administration on oestrus response in postpartum anoestrous cows

Abstract

The oestrus responses following Crestar administration with gonadotrophin in postpartum anoestrous cows was studied. In the treatment group, 9 out of 10 postpartum anoestrous cows exhibited oestrus between 22.00 to 37.50 hr after removal of Crestar ear implant. The control cows exhibited natural oestrus between 66 to 160 days of placebo treatment. The mcan duration of oestrus was 19.11 ± 0.34 and 15.40 ± 2.15 hr in the treatment and control groups. respectively. with no significant difierence. All cows of both the groups ovulated (100%) following onset of ocstrus. In the treatment group. out of 9 cows induceed to oestrus 33.33, 55.56 and 11.11 % showed intense, moderate and weak symptom of oestrus rcspectively. Tile corresponding percentage in the control group were 20, 40 and 40 respectively. Status of the genital tract at hormonally induced oestrus was similar with naturnl oestrus in postpartum indigenous cows.