Pregnancy-Associated Glycoprotein and Progesterone Concentrations during Pregnancy Failure in Bedouin Goat from the Southwest of Algeria

Selecting specific aptamers that bind to ovine pregnancy-associated glycoprotein 7 using real serum sample-assisted FluMag-SELEX to develop magnetic microparticle-based colorimetric aptasensor

The pregnancy-associated glycoproteins (PAGs) have been widely used as biomarkers for the early diagnosis of pregnancy in cattle and sheep. This study aimed to obtain the single-stranded DNA aptamers that specifically bound to ovine pregnancy-associated glycoprotein 7 (ovPAG7) with high affinity (K_d = 9.8-32.4 nM) using real serum sample-assisted FluMag-systematic evolution of ligands by exponential enrichment (SELEX). Subsequently, the selected aptamers were applied to fabricate an ultrasensitive colorimetric aptasensor for ovPAG7 detection based on functionalized magnetic microparticles and hybridization chain reaction. Under the optimized conditions, the colorimetric aptasensor exhibited a broad linear range (0.2-500 ng mL^-1), low detection limit (0.081 ng mL^-1), good recovery rate (94.5-109.1%), and high repeatability (relative standard deviation of 4.02-8.16%) in ovPAG7-spiked serum. Furthermore, this aptasensor was applied to measure the ovPAG7 in serum samples of ewes for pregnancy diagnosis. Blood samples were collected from Chinese Merino ewes on days 22, 28 after artificial insemination (AI) for ovPAG7 detection, respectively. Transrectal ultrasonography diagnosis of pregnancy 45 days after AI was the reference (gold) standard for all PAG tests. Diagnostic sensitivity, specificity, and accuracy of the proposed aptasensor were 95.8, 87.5, and 92.5% at day 22 and 95.8, 90.6, and 93.7% at day 28, respectively. The degree of agreement (Kappa) between developed aptasensor and ultrasonography diagnosis 22 and 28 day after AI were higher than 0.8. These results illustrated that the aptasensor was proved to be a sensitive, reliable and cost-effective way of measuring PAG and might be a useful means of pregnancy detection in ewes.

Endocrine, energy, and lipid status during parturition and early lactation in indigenous goats native to the Algerian Sahara

Background and Aim:

Goats are widely distributed in southwest Algeria. The Saharan goat is perfectly adapted to the harsh conditions of arid areas, and it is characterized by resistance to long photoperiod and reduced metabolic needs, allowing the survival of its offspring by maintaining lactation. Several studies have demonstrated that parturition and lactation are critical periods that induce hormone, energy, and lipid status changes in mammals. However, the relationship between the blood biochemical parameters of parturition control and lactation functions in the Algerian Saharan goat has not been thoroughly documented. Therefore, this study assesses hormone and metabolite levels during parturition and early lactation in Saharan goats reared in arid areas.

Materials and Methods:

Experiments were performed on 14 multiparous female goats, and blood samples were collected during parturition, 4 days postpartum (D1PP-D4PP), and during the first 12 weeks of lactation (W1-W12) to analyze prolactin, cortisol, glucose (GLU), total proteins (TP), cholesterol (CHO), triglycerides (TGs), total lipids (TL), low-density lipoproteins (LDLs), high-density lipoproteins (HDLs), and very LDLs (VLDLs).

Results:

Statistical data analysis revealed a significant (p<0.05) increase in plasma prolactin concentrations at W1 after parturition, reaching maximum values at W3 and W9, and remained high until W12 of lactation. Plasma cortisol levels were high at parturition, reaching two peaks at W3 and W9, and then decreased at W5, W7, and W12 of lactation. No significant changes were found in serum GLU levels during the first 7 weeks of lactation compared with parturition day; then, the levels became significantly (p<0.05) lower at W8, W11, and W12 of lactation. Plasma TP increased significantly (p<0.05) at D3PP, W1, and W4, then decreased significantly (p<0.05) at W8. In addition, this decrease coincided with that of GLU production. Serum CHO, TGs, TL, LDLs, and VLDLs, were low at parturition and high at D4PP and during the first 3 months of lactation. Furthermore, HDL levels were low at D3PP, 1^st, and 3^rd months and high at the 2^nd month of lactation.

Conclusion:

This study emphasized the impact of parturition and the 1^st weeks of lactation on endocrine and metabolic changes in indigenous goats living in the Algerian Sahara Desert. These results can be used to monitor and improve farming management and understand physiological adaptive strategies, mainly lactation function sustainability, of this goat living in marginal zones.

Temporal changes in circulating progesterone and pregnancy-associated glycoprotein concentrations in Jakhrana goats with failed pregnancy

This study aimed to evaluate the changes in circulating Progesterone (P4) and Pregnancy-Associated Glycoprotein (PAG) during pregnancy interrupted by abortion and to identify the better predictor of abortion risk in Jakhrana goats. Pluriparous goats (18) were involved in the study. Out of 15 pregnant goats, 3 goats were aborted during the third or fourth months of pregnancy. In the normal pregnancy, mean P4 concentration (13.96±0.27 ng/mL) remained unchanged throughout gestation whereas, the PAG level increased during early pregnancy and reached to the highest level (S-N=2.14±0.40) on day 51 of gestation. In non-pregnant goats, the P4 (0.3±0.03 ng/mL) and PAG (0.06±0.03) were significantly lower compared to the goats with maintained or failed pregnancy. In goats with the failed pregnancy, the PAG level started to decline about 12 days before the drop in P4 concentration (day 33.0±2.1 vs 21.3±3.5, before the occurrence of abortion). The mean PAG level in goats with failed pregnancy (0.33±0.03) was 4.8-folds lower compared to the animals with maintained pregnancy (1.58±0.08). In conclusion, the P4 and PAG concentrations in maternal circulation are changed by the pregnancy status and abortion. Plasma PAG is a more reliable predictor for the high risk of pregnancy failure than the P4 concentration in goats.

Temporal changes in plasma profile of pregnancy-associated glycoprotein, progesterone and estrone sulfate associated with fetal number during early- and mid-pregnancy in goats

This study was designed to investigate plasma profile of pregnancy-associated glycoprotein (PAG), progesterone (P4) and estrone sulfate (E₁S) during early- and mid-pregnancy. The goal was to explore the relationships with values for reproductive variables, to detect the most reliable predictor variable, and to identify the most desirable time point for blood collection for determining fetal number in goats. After ultrasonographic examination at d35-40 post-mating, blood sampling of 15 pregnant goats (total 18) was continued until d114. The PAG profile was characterized by gradual increase during early pregnancy from d26 to d51 and thereafter concentrations were relatively constant until d114 of gestation. The effect of fetal number on plasma PAG, P4 and E₁S was first evident on d28, d51 and d26, respectively. During mid-pregnancy, does with twins had a greater (P < 0.05) PAG (S-N = 2.54 ± 0.12 compared with 1.59 ± 0.11), P4 (18.91 ± 0.67 compared with 14.51 ± 0.47 ng/mL) and E₁S (16.34 ± 0.76 compared with 11.32 ± 0.44 ng/dL) as compared with does with a singleton fetus. Plasma PAG but not P4 and E₁S was positively correlated with fetal number and birth weight of kids during early pregnancy. Multivariate linear regression and discriminant function analyzes allowed for identification of plasma PAG as the most reliable predictor for fetal number and birth weight of kids. Furthermore, d58 was the most suitable single time point for prediction of fetal number using PAG as a biomarker. In conclusion, plasma profile of PAG, P4 and E₁S was affected by fetal count. Plasma PAG was identified as the most reliable predictor variable of fetal number and birth weight of kids as compared to plasma P4 and E₁S.

Analysis of the energetic metabolism in cyclic Bedouin goats (Capra hircus): Nychthemeral and seasonal variations of some haematochemical parameters in relation with body and ambient temperatures

Several studies have examined changes in some haematochemical parameters as a function of the different physiological status (cyclic, pregnant and lactating) of goats, but no relevant literature has exhaustively investigated these variations from anestrous to estrous stages in cyclic goats. In this paper, we report nychthemeral and seasonal variations in ambient and body temperatures, and in some haematochemical parameters (glycemia, cholesterolemia, triglyceridemia, creatininemia and uremia) measured during summer, winter and spring, in seven (7) experimental cyclic female Bedouin goats (Capra hircus) living in the Béni-Abbès region (Algerian Sahara desert). Cosinor rhythmometry procedure was used to determine the rhythmic parameters of ambient temperature and haematochemical parameters. To determine the effect of time of day on the rhythmicity of the studied parameters, as well as their seasonality, repeated measure analysis of variance (ANOVA) was applied. The results showed that in spite of the nychthemeral profile presented by the ambient temperature for each season, the body temperature remained in a narrow range, thus indicating a successful thermoregulation. The rhythmometry analysis showed a circadian rhythmicity of ambient temperature and haematochemical parameters with diurnal acrophases. A statistically significant effect of the time of day was shown on all studied haematochemical parameters, except on creatininemia. It was also found that only uremia, cholesterolemia and triglyceridemia followed the seasonal sexual activity of the studied ruminant. This study demonstrated the good physiological adaptation developed by this breed in response to the harsh climatic conditions of its natural environment.