Plasma profiles of progesterone and total oestrogens in buffaloes (Bubalus bubalis) around parturition

Abstract

SummaryBlood samples were collected three times weekly for 21 days before and after calving (day 0) from 29 buffalo cows and 22 buffalo heifers. Plasma concentrations of progesterone and total oestrogens were quantified by validated radioimmunoassays. Ovarian activity and uterine involution were monitored by rectal palpation at the sampling times and extended up to 60 days postpartum. The concentration of plasma progesterone in cows declined from 3·0 ± 0·2 ng/ml (mean ± S.E.) during days 21–17 before calving to 2·1 ± 0·1 ng/ml at day −3, followed by a rapid fall during the last 3 days of gestation, reaching 1·2 ± 0·3 ng/ml at the day of parturition. In heifers, plasma progesterone values increased slightly from 2·9 ± 0·2 ng/ml at days 21–19 before parturition to 3·4 ± 0·3 ng/ml by day −1 and then fell sharply to 2·1 ± 0·1 ng/ml at calving time. During the postpartum period, plasma progesterone decreased gradually and reached baseline values after day 15 postpartum, when the residual corpus luteum of pregnancy had completely regressed in all the animals studied. The plasma concentrations of total oestrogens started to increase at day −15 in cows and day −5 in heifers from below 40 pg/ml to 122·5 ± 51 pg/ml for cows and 100·7 ± 3·4 pg/ml for heifers by day −1. This was followed by a sharp increase to 251·2 ± 17·3 and 240·5 ± 10·1 pg/ml in these animals at the day of calving. Immediately after parturition, total oestrogens dropped abruptly to the lowest values and remained below 30 pg/ml in all cows and heifers until the end of the sampling period. We concluded that female foetuses significantly (P < 0·05) increased the maternal total oestrogens. Moreover, animals having postpartum disorders had significantly higher values for progesterone (P < 0·05) and lower values for total oestrogens (P < 0·01) than those having normal puerperal periods, but the magnitude of this difference varied in samplings between cows and heifers.