Pregnancy-associated glycoprotein concentrations during pregnancy and the postpartum period in Azawak Zebu cattle.

Specific RIA systems were developed and used to measure pregnancy-associated glycoprotein (PAG) concentrations during gestation and the postpartum period in Azawak Zebu cows. Twelve females were palpated per rectum and diagnosed as pregnant. Blood samples were taken at 5-10-day intervals from approximately Week 8 of gestation until Week 10 postpartum (pp). One Zebu cow (Z15) initially diagnosed as pregnant showed PAG concentrations lower than the assay sensitivity (<0.20 ng/ml) and did not calve. Another cow (ZSand) showed abnormally high PAG concentrations during gestation and was excluded from the general PAG profile. The 10 other Zebu cows exhibited a very similar PAG profile. In these animals, concentrations increased progressively from Week 8 to 35 of gestation (from 6.0+/-4.2 to 196.0+/-34.8 ng/ml), remaining relatively constant until Week 39 (210.8+/-74.8 ng/ml), when they increased sharply to reach their highest level (1095.6+/-607.2 ng/ml) at around parturition. After delivery, PAG concentrations declined significantly (P<0.05) until Week 2 postpartum (348.4+/-85.6 ng/ml) and slowly until Week 10 postpartum. Our results revealed that the PAG pattern in Zebu cattle was similar to those of taurine breeds during the first two trimesters of pregnancy, but differed in the peripartum period.

Isolation and partial characterization of three pregnancy-associated glycoproteins from the ewe placenta.

Pregnancy-associated glycoproteins (PAGs) are synthesized in the outer epithelial layer of the placenta in artiodactyls. In this work, three novel ovine PAGs were isolated from late-pregnancy fetal cotyledons and characterized biochemically. The isolation procedure included acid and ammonium sulfate precipitations and anion and cation exchange chromatographies. The isolated PAGs have different NH(2)-terminal amino acid sequences (RGSXLTILPLRNMRDIVY, ISRVSXLTIHPLRNIMDML, and RGSNLTIHPLRNIRD) and apparent molecular masses (55, 57, and 59 kDa). Each shows several isoforms with different pI values. The three proteins share high sequence identity with each other and with other ovine, bovine, and caprine PAGs. They have not been described previously. The ovPAG-59 sequence differs from the previously identified ovPAG-4 sequence (determined by DNA cloning and sequencing) at only one position among the 15 N-terminal residues. The newly characterized ovPAGs and the procedure used to isolate them will be helpful in producing new antisera for investigating PAG secretion in pregnant ewes.

The monitoring of bovine pregnancies derived from transfer of in vitro produced embryos.

Both an increased rate of embryonic, foetal and perinatal losses, and the occurrence of deviations in foetal and placental development are associated with bovine pregnancies obtained from in vitro produced embryos. This thus requires for a more accurate and frequent monitoring of foetal and maternal functions during pregnancies. Such approaches will enable to establish the period during which these losses and deviations in development occur and to plan possible clinical interventions. This paper reviews some recent data on return rates, late embryonic and foetal losses in recipients after the transfer of either MOET, IVF or nuclear transfer embryos. Special attention is paid to the diagnostic value of measurements of pregnancy specific/associated proteins and progesterone in maternal plasma. Possibilities to measure foetal body sizes, size of placentomes and foetal heart rate by means of transrectal or transabdominal ultrasonography are illustrated with data from the literature and with recent results from our own large field study with MOET, IVP-co-culture and IVP-SOF embryos.