Progesterone and oestrogen concentrations in plasma of Barbary sheep (aoudad, Ammotragus lervia) compared with those of domestic sheep and goats during pregnancy

Abstract

Steroid hormone concentrations have been measured in the peripheral plasma of 3 Barbary sheep over 3 breeding seasons. During pregnancy mean progesterone values rose initially and after a small decline between Days 30 and 50, increased again and remained between 17 and 28 nmol/l until the last 2 days of pregnancy. Oestradiol-17 beta reached a peak of about 300 pmol/l during mid-pregnancy, increasing to over 400 pmol/l in the last 5 days of pregnancy. Oestrone sulphate began to increase in concentration from about Day 40 of pregnancy and reached a peak of about 19 nmol/l by Day 120. Following a slight decrease from Day 130, there was a further rise in values just before parturition. Values for these steroids in the Barbary sheep studied were between those expected for domestic sheep and goats.

Assessment of Progesterone Concentration Using Enzymeimmunoassay, for Early Pregnancy Diagnosis in Sheep and Goats

“…Robertson and Sarda (1971) proposed 0.5 ng/ml and Zarkawi (1997) 1.0 ng/ml (3.18 nmol/l), both using RIA for P 4 determination. Besides, mean P 4 concentration of pregnant ewes in the present experiments was higher than concentrations reported by other authors who have used either RIA (Shemesh et al 1979; Hamon and Heap 1990; Al‐Merestani et al 1999) or EIA (McPhee and Tiberghien 1987; Dickie and Holzmann 1992; Mukasa‐Mugerwa et al 1992) for P 4 determination between 10 and 35 days of pregnancy. These deviations between P 4 concentrations of pregnant ewes and between the proposed discriminatory levels as compared with other authors’ results, may be attributed to small differences of the reference range existing between RIA and EIA (Eckersall and Harvey 1987), although both methods have been proved accurate for P 4 determination.…”

Metabolic Profile of Pre-Pregnancy, Pregnancy and Early Lactation in Multiple Lambing Sakız Ewes

“…Similarly, Bekeova et al [16] reported that the progesterone concentration dropped sharply from 14 days before to 36 h after parturition. As reported by most investigators [15,[19][20][21]23] in the present study, plasma progesterone levels were significantly higher during pregnancy than in pre-pregnancy due to the progesterone secreted by the corpus luteum. Levels insignificantly increased on the 120th day of pregnancy.…”

“…In this study, plasma estradiol-17ß levels did not statistically differ during the different periods. These results are similar to those presented by Alaçam et al [18] but do not correspond to the findings of Henze et al [14], Hamon and Heap [15] and Bekeova et al [16]. These researchers reported that plasma estradiol-17ß concentrations changed during pregnancy.…”

“…Hamon and Heap [15] reported that during pregnancy mean progesterone values rose initially and after a small decline increased again between days 30 and 50. Similarly, Krajnicakova et al [19] determined that progesterone levels decreased significantly, reaching their lowest values on the day of insemination and increased with the progress of pregnancy, reaching maximum in the 5th month.…”

“…Hamon and Heap [15] determined that estradiol-17ß reached a peak of about 300 pmol/l during mid-pregnancy, increasing to over 400 pmol/l in the last 5 days of pregnancy. Bekeova et al [16] reported that the estradiol concentration declined steeply from 14 days before to 4 days after parturition, then varied at levels below those found 14 days before parturition, with slight rises on days 17 and 42 postpartum.…”