Pregnancy-Associated Glycoproteins Profile and PAGs/P4 Ratio Biomarker to Diagnosis Pseudopregnancy in Dairy Goats

Pseudopregnancy (PPG) is a common reproductive disorder in dairy goats, characterized by the accumulation of sterile fluid in the uterus and persistence of a corpus luteum, leading to temporary infertility and reduced farm efficiency. This study mainly aimed to determine the profile of pregnancy-associated glycoproteins (PAGs) in dairy goats, and to evaluate the potential of the PAGs/P4 ratio as a novel biomarker for PPG diagnosis. A total of 605 Saanen and crossbreed goats were evaluated via transabdominal ultrasonography, at 34.5 ± 0.5 days after bucks´ removal, in four intensive dairy farms, and presenting an overall incidence of 7.8%. Blood samples from PPG (n = 47), non-pregnant (NPG; negative control; n = 11) and pregnant (PG; positive control; n=10) does were collected for PAG and P4 analysis. Plasmatic levels of PAGs of PPG was similar (0.08 ± 0.02) to NPG (0.13 ± 0.04; p >0.05), but lower than PG group (1. 45 ± 0.04 S-N OD; p <0.001). PAGs/P4 ratio was lower in PPG (0.01 ± 0.11; p < 0.001)) than in NPG (0.24 ± 0.23) and PG (0.18 ± 0.23) groups. The sensitivity and specificity of this biomarker to diagnosis PPG was 98.8% and 100%, respectively. The area under the survival curve (AUC) was 99.6 for cut-off of 0.04 and 97.9% of sensibility and specificity. This study suggests that the PAGs/P4 ratio can serve as a reliable biomarker for PPG diagnosis, helping to distinguish it from pregnancy and non-pregnancy, and improving reproductive management in dairy goats.