The Level of Prolactin, Serum Amyloid A, and Selected Biochemical Markers in Mares Before and After Parturition and Foal Heat.
Authors: Krakowski Leszek, Brodzki Piotr, Krakowska Izabela, Opielak Grzegorz, Marczuk Jan, Piech Tomasz
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Krakowski et al. (2020) tracked prolactin, serum amyloid A (SAA), and key biochemical markers across the perinatal window in 14 Polish Coldblood mares, collecting blood samples at two weeks pre-partum, 24 hours post-delivery, during foal heat (day 9), and nine days after ovulation. Prolactin peaked dramatically within 24 hours of foaling before declining significantly during oestrus and post-breeding, whilst SAA remained within normal reference ranges overall but showed a noteworthy elevation by day 9 post-partum—a timing that warrants consideration when interpreting acute phase responses in early lactation. Total cholesterol, aspartate aminotransferase, and total protein all increased substantially at 24 hours post-delivery, then normalised by foal heat, whereas magnesium, phosphate, and calcium demonstrated no meaningful fluctuations throughout the sampling period. The fertility outcome of 43% pregnancy rate during foal heat aligns with typical commercial breeding expectations, and the absence of clinical abnormalities suggests these biochemical shifts represent normal physiological adaptation rather than pathological concern. For practitioners, these findings establish baseline reference data for the periparturient mare and suggest that moderate transient elevations in liver enzymes and acute phase proteins immediately post-foaling, when accompanied by normal electrolyte status and clinical presentation, are reassuring indicators of uncomplicated recovery rather than harbingers of metabolic or inflammatory disease.
Read the full abstract on PubMed
Practical Takeaways
- •Monitor prolactin and SAA levels as biomarkers during the perinatal period—elevated SAA on day 9 post-foaling may indicate inflammatory response requiring attention
- •Expect transient increases in cholesterol, AST, and total protein immediately after delivery as normal physiological changes; these normalize by foal heat
- •Electrolyte supplementation is not indicated for mares during normal perinatal periods, as serum levels remain stable without intervention
Key Findings
- •Prolactin levels peaked 24 hours after delivery (highest) and were lowest during foal heat and 9 days after ovulation
- •Serum amyloid A remained within normal ranges except for a significant increase on day 9 after foaling
- •Total cholesterol, AST, and total protein increased significantly 24 hours post-delivery but decreased during foal heat and after ovulation
- •Electrolyte levels (Mg2+, P+, Ca2+) remained stable throughout the perinatal period with no significant changes
- •Pregnancy rate during foal heat was 43% with no health disturbances observed during normal perinatal period