Analytical Assessment of Serum Calcium Homeostasis Regulatory Hormones in Periparturient Dairy Cows Supplemented with Anionic Salts in Kaduna State, North West Nigeria

Prepartum anionic salt supplementation is used in some commercial dairy systems to prevent clinical hypocalcaemia at calving by activating parathyroid hormone-mediated calcium homeostasis responses, yet its biochemical effectiveness has not been analytically evaluated in Nigerian dairy conditions. This study assessed serum calcium homeostasis regulatory hormones in periparturient Friesian-Zebu cows supplemented with anionic salts in Kaduna State, North West Nigeria. Sixty dairy cows were allocated to control and anionic salt-supplemented groups in the last four weeks prepartum. Serum total calcium, ionised calcium, parathyroid hormone, calcitonin, and 1,25-dihydroxyvitamin D3 were measured at three weeks prepartum, at calving, and at one, three, and seven days postpartum. Clinical monitoring for milk fever was conducted through the first week postpartum. Supplemented cows maintained higher ionised calcium concentrations at calving compared to controls and demonstrated earlier and more pronounced parathyroid hormone responses when calcium demands increased at the onset of lactation. Calcitonin concentrations were lower in supplemented cows at calving, suggesting less need to suppress calcium from non-dietary sources. Milk fever incidence was reduced from 30% in controls to 8% in supplemented cows. These analytical findings confirm that anionic salt supplementation activates parathyroid hormone-mediated calcium homeostasis mechanisms at parturition and supports its adoption as an evidence-based preventive intervention for hypocalcaemia in commercial Kaduna State dairy herds. Keywords: anionic salts, calcium homeostasis, parathyroid hormone, milk fever, periparturient cows.