Comparative Analysis of Serum Calcium, Vitamin D, and Parathyroid Hormone in Pregnant and Non-Pregnant Arabian Mares

Document Type : Original Article

Authors

1 Department of Animal Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran

2 Department of Veterinary, Shk.C., Islamic Azad University, Shahrekord, Iran

Abstract

This study aimed to investigate serum concentrations of calcium, vitamin D [25-hydroxyvitamin D3; 25(OH)D3], and parathyroid hormone (PTH) in Arabian mares in Iran, establish reference intervals for these parameters, and assess the potential effects of pregnancy and parity. Blood samples were collected from 30 clinically healthy Arabian mares, divided into three groups based on pregnancy and parity: non-pregnant mares (n = 10), pregnant mares in their first to third parity (n = 10), and pregnant mares in their sixth to sixteenth parity (n = 10). Serum calcium was measured using a colorimetric method, while vitamin D and PTH concentrations were determined using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using one-way ANOVA, with P < 0.05 considered statistically significant. Mean serum concentrations of calcium, vitamin D, and PTH in all mares were 11.06 ± 0.89 mg/dL, 6.15 ± 1.2 ng/mL, and 24.57 ± 17.38 pg/mL, respectively. Pregnancy did not significantly affect serum concentrations of calcium, vitamin D, or PTH (P > 0.05). Parity had no significant effect on serum concentrations of calcium, PTH, or vitamin D (6.87 ± 1.47 ng/mL in mares in their sixth to sixteenth parity vs. 5.77 ± 0.73 ng/mL in mares in their first to third parity, P = 0.06). Serum calcium, vitamin D, and PTH concentrations remain relatively stable throughout pregnancy in Arabian mares, reflecting effective homeostatic regulation. Parity did not have a significant impact on these parameters. These results provide valuable reference data for monitoring mineral metabolism and guiding nutritional management in breeding mares.

Keywords

Main Subjects

References

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Veterinary and Comparative Biomedical Research
Volume 3, Issue 2
June 2026
Pages 9-16

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