The relationship between concentrations of vitamin D-binding protein (DBP) in serum and colostrum of mares and in serum of their foals in the neonatal period.

This research investigates the relationship between the levels of vitamin D-binding protein (DBP) found in the serum and colostrum of mares, and in the serum of their newborn foals. The results show that the DBP concentration in newborn foals is influenced by factors unique to the foal, independently of their mother’s DBP levels, her age, or number of previous births.

Study Design

• The researchers aimed to understand whether the serum DBP level in mares is connected to the levels of this protein in colostrum (first milk produced during lactation) and in the serum of their offspring.
• The study included 77 mares for serum collection, 72 mares for colostrum collection, and 69 thoroughbred foals for blood sample collection. Various factors such as the mare’s age, their number of prior births, the delivery month, and the feeding of colostrum to the foals were considered.
• Blood from the foals was collected from the umbilical vein during birth, and from the external jugular vein 36-48 hours after birth. Colostrum was obtained from the mares after delivery, and their blood was sampled 36-48 hours after birth.
• The DBP concentration was measured using an enzyme-linked immunosorbent assay (ELISA), a test that checks for specific proteins in a sample.

Findings

• There was no dependency between the DBP concentrations in the serum of the newborn foals and those in the mother’s serum, her age, or the number of foals she had previously given birth to.
• The DBP level in colostrum had a lower concentration compared to the mare’s serum and showed no correlation with the mare’s serum levels.
• Feeding colostrum to the foals had no impact on the DBP level in their serum.

Conclusions

• The results indicate that serum DBP concentration in newborn foals is determined by factors that directly affect the foal, independently of the mare’s DBP levels, her age, or her number of prior births.
• The lack of connection between the plasma and colostrum levels of DBP suggests that this protein might be independently synthesized in the mammary gland or that there exists specific transportation mechanisms in the mammary gland, which regulate the levels of DBP in colostrum and blood.