Serum progesterone profile in prepubertal Hampshire gilts following boar contact and hormone treatment

Abstract

Healthy prepubertal Hampshire gilts (18) randomly divided into 3 equal groups to monitor the serum progesterone level after induction ofpuberty by boar contact and hormonal treatment. Gilts of group 1 were allowed direct contact with rotation of 2 vasectomized boars for 2 months or till exhibition of the oestrus, whichever was earlier. Gilts of group ~ were administered 400 IU PMSG followed by 200 IU HCG intramuscularly at around 165 days of age. The gilts of control group (group 3) were administered with sterile normal saline solution intramuscularly. The mean serum progesterone concentrations before treatment and on the day of oestrus were O.53±O.04 and O.46±O.02 ng/ml; O.48±0.06 and O.50±O.02 ng/ml and O.45±O.04 and O.40±O.03 ng/ml in gilts of group 1, 2 and 3 respectively. The mean serum progesterone concentration increased from 1.31±O.12, 1.86±O.7I and 1.13±O.03 ng.lml on the day 3 of oestrous cycle to the highest level of 9.90±O.33, 11.62±O.44 and 8.95±O.17 ng/rol on day 15 of oestrous cycle in the 3 respective groups. Thereafter, progesterone concentration decreased sharply from 1.72±O.05, 1.82±O.17 and 1.15±O.04 ng/ml on day 18 to O.48±O.03, O.48±O.03 and O.45±O.04 ng/ ml on the day of onset of next oestrus in group 1, 2 and 3 gilts, respectively.