Disease & heat resistance

Variation in Vitamin D Concentration and Vitamin D Receptor Expression in Holstein Dairy Heifers Classified Based on Their Estimated Breeding Values of Immune Responses

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Abstract

Nutritional status plays a critical role in shaping immune competence in dairy cattle, with vitamin D emerging as a key regulator of both innate and adaptive immunity. Beyond its established role in calcium metabolism and bone health, vitamin D modulates immune function through its effects on cellular differentiation, cytokine production, and antimicrobial peptide expression. The objective of this study was to investigate the association between serum vitamin D concentrations and immune response (IR) phenotypes in Holstein dairy heifers classified as high, average, or low immune responders based on their estimated breeding values (EBVs) for antibody-mediated (AMIR) and cell-mediated (CMIR) immune responses.Twenty-four Holstein heifers previously phenotyped for immune responsiveness using the High Immune Response (HIR) technology were analyzed. Serum vitamin D concentrations were quantified using a validated commercial enzyme-linked immunosorbent assay (ELISA). Statistical analyses using general linear and mixed models evaluated the effects of AMIR, CMIR, and their interaction on serum vitamin D levels. Low immune responders exhibited the highest vitamin D concentrations, whereas high responders had the lowest. The continuous model including AMIR, CMIR, and their interaction was significant (R² = 0.33; P = 0.0403), with CMIR demonstrating a stronger association than AMIR. Heifers classified as high AMIR and CMIR responders had the lowest mean serum vitamin D (~59 and ~57 ng/mL, respectively), while low responders averaged ~80-83 ng/mL, supporting an inverse relationship between IR phenotype and circulating vitamin D.These findings suggest that heightened immune activation may increase intracellular utilization of vitamin D, potentially influenced by differential expression of the vitamin D receptor (VDR) and vitamin D binding protein (DBP). VDR, a nuclear receptor, mediates the genomic effects of vitamin D by regulating transcription of immune-related genes. Variability in vitamin D Receptor (VDR) expression may be an influencing factor and is currently under investigation. Genetic polymorphisms in these proteins may underlie observed differences in vitamin D metabolism across immune phenotypes. Furthermore, vitamin D enhances both antibody- and cell-mediated responses by supporting T- and B-cell differentiation and antimicrobial peptide production, reinforcing its immunomodulatory role.This study provides novel insight into the molecular and physiological links between genetic immune potential and vitamin D metabolism in dairy cattle. Understanding how immunogenetic traits influence vitamin D utilization and receptor expression is expected to inform targeted breeding and nutritional strategies to enhance immune competence, disease resistance, and overall herd productivity.

Keywords: 2026

How to Cite:

Hanna, K., Wagter-Lesperance, L., Gallo, N. & Mallard, B., (2026) “Variation in Vitamin D Concentration and Vitamin D Receptor Expression in Holstein Dairy Heifers Classified Based on Their Estimated Breeding Values of Immune Responses”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285983. doi: https://doi.org/10.31274/wcgalp.23830

Rights: 1