Impact of copper deficiency in cows on immune system function in offspring: a study using lymphocyte immunophenotyping

Abstract

Copper (Cu) deficiency is a common, often subclinical problem in dairy cattle herds that can adversely affect haematopoietic processes and immune function. This study aimed to evaluate the effect of hypocupraemia in cows on selected haematological parameters and identify the immunophenotype of calf lymphocytes. Material and Methods: The study included Holstein–Friesian cows and their calves aged two to six weeks, which were divided into two groups: a hypocupraemic group (17 cows and 17 calves) and a normocupraemic group (18 cows and 18 calves). Haematological and biochemical analyses were performed, and lymphocyte subpopulations (CD4⁺, CD8⁺, CD21⁺ and major histocompatibility complex (MHC) class II⁺ were determined by flow cytometry. Results: Cows with hypocupraemia exhibited reduced HGB and HCT values. Calves born to cows with Cu deficiency showed decreased erythrocyte indices, a reduced CD4⁺ : CD8⁺ ratio and a lower percentage of CD21⁺ B lymphocytes and MHC class II⁺ lymphocytes, indicating impaired immune function. In these calves, the CD4⁺ : CD8⁺ ratio was significantly lower compared to healthy cows and calves, suggesting an imbalance in T-lymphocyte subpopulations. Conclusion: The obtained results indicate that even moderate copper deficiency in pregnant cows may negatively influence the haematological and immunological status of their offspring. These findings underline the necessity of systematic monitoring of copper status in dairy herds in order to prevent subclinical deficiencies and their long-term consequences for calf health and immunity.