Pregnancy-specific protein B, progesterone concentrations and embryonic mortality during early pregnancy in dairy cows

Abstract

Pregnancy-specific protein B (PSPB) and progesterone concentrations were determined by RIAs in venous plasma during early pregnancy after 177 artificial inseminations (AI) performed in 76 cows and 71 heifers. The females were bled at 24, 26, 30\p=n-\35 days and \m=~\70 days (for non-returns to oestrus) after AI. In non-pregnant females without extended CL maintenance (progesterone < 1\m=.\5 ng/ml on Day 24) and or showing a normal time of return to oestrus (Group 1, N = 63), PSPB concentrations were undetectable whatever the stage after AI except in 2 cows. In pregnant animals (N = 83; Group 2) progesterone concentrations were > 10 ng/ml from Day 24 to the time of rectal palpation and PSPB concentrations rose continuously from 0\m=.\42\m=+-\0\m=.\07 (s.e.m.) ng/ml (Day 24) to 4\m=.\06 \ m=+-\ 0\m=.\3 ng/ml (time of rectal palpation). No coefficient of correlation between PSPB and progesterone concentrations was significant whatever the day of gestation studied. In cows with extended luteal function and subsequently found to be non-pregnant (late embryonic mortality) PSPB was undetectable (N = 21; Group 3) or detectable (N = 10; Group 4) at Days 24, 26 and/or 30\p=n-\35of pregnancy. At 24 and 26 days after AI progesterone concentrations were intermediate between those of Groups 1 and 2. At Day 24 females of Group 4 had higher progesterone concentrations than those of Group 3 (P < 0\m=.\05), but no differences between these two groups existed at subsequent stages after AI. Animals of Group 4 had lower PSBP concentrations than those of Group 2 between Days 24 and 30\p=n-\35 (P < 0\m=.\025) but at the time of rectal palpation PSPB values fell to undetectable levels in all but 1 cow of Group 4. We conclude that (1) most pregnancy failures in cows are due to nonfertilization or early embryonic death and if AI is performed after 70 days post partum >95% of these females have no detectable PSPB concentrations; (2) peripheral progesterone concentrations are lower at Days 24\p=n-\26after AI in cows with late embryonic mortality than in pregnant cows; (3) only 30% of non-pregnant females with extended luteal function (late embryonic mortality) have detectable PSPB levels which are lower than in pregnant cows; and (4) in pregnant animals there is no correlation between PSPB and progesterone concentrations. This suggests that under physiological conditions PSPB has no major effect on progesterone production or vice versa.

Pregnancy-specific protein B and progesterone concentrations in French Alpine goats throughout gestation

“…As previously shown by Thorburn & Schneider (1972) and Thibier et al (1980), progesterone values between 21 and 24 days in those goats were close to or lower than 1 ng/ml. Although constantly low, plasma PSPB concentrations in the 7 non-pregnant goats were detectable, contrary to findings for cows (Humblot et al, 1988a). The goats were sampled a long time after the previous kidding and this rules out possible interference with post-partum secretion of PSPB.…”

Effects of acetoacetate and d-β-hydroxybutyrate on bovine in vitro embryo development in serum-free medium

“…All embryos were transferred to the uterine horn adjacent to a corpus luteum. Pregnancy diagnosis was established by plasma progesterone determination on Day 21, bovine Pregnancy-Speci®c Protein B (bPSPB) [18] on Day 30 and ultrasonographic scanning after Day 50.…”

Recent Possibilities for the Diagnosis and Pharmacological Control of Pregnancy Loss in Dairy Cow

“…These findings indicate that the presence of bPSPB and bPAG1 in the plasma of cows during early stages of the postpartum period may limit their use under field conditions. If only these cows are selected for the protein tests which are inseminated after day 50 [31] or day 70 [32][33][34], post calving interference with the residual bPSPB and bPAG1 in the peripheral circulation during the postpartum period can be minimal. A further limitation after LEM is that protein levels may remain above the threshold level, although the concentration of both proteins decreases steadily [35,36].…”

“…According to a recent study in herds with a high incidence of EFM of a non-infectious nature at PD (days [28][29][30][31][32][33][34], treatment at the time of PD with progesterone in cows with one corpus luteum and with GnRH in cows with two or more corpora lutea should offer considerable benefits [102]. …”

“…It is generally accepted that FR in healthy dairy cattle is of the order of 85 to 90% [1] and the CR is presently around 33 to 41%. The CR has decreased from 66% since 1951, to about 50% until 1975, and further more until recently to about 33.1% in Spain [2], 33.4% in Israel [3], 37% in Canada [4] or 41% in Japan [5]. Therefore 44% to 58% of pregnancies are lost during gestation.…”