Investigation of the relationship between serum cytokine profile and vitamin d in calves with neonatal diarrhea

Diarrhea in calves in the neonatal period causes significant losses. Although there are many different causes of diarrhea in this period, the most important causes are infections of viral, bacterial and protozoal origin. It is vital for calves to have a functional immune system in the fight against these infections. The immune system is examined under two main headings as innate and adaptive immune systems. Cytokines synthesized by both innate and acquired immune system cells are involved in the development and regulation of the immune response against infectious agents. Based on the determination of circulating cytokine levels, an evaluation can be made about the functions of the immune system. In recent years, it has been determined that vitamin D has very important roles in both innate and acquired immune systems apart from its classical functions in calcium metabolism. There is no study in the literature investigating the relationship between vitamin D and cytokines in calves with diarrhea. In this study, it was aimed to investigate the relationship between vitamin D and serum cytokine profile in neonatal calf diarrhea caused by bacterial, viral and protozoal pathogens. The material of the study consisted of totally 40 calves from 5 different groups; E. coli (n=8), Rotavirus (n=8), Coronavirus (n=8), C. parvum (n=8) and Control (n=8) groups. Using blood samples taken from all animals, serum vitamin D levels were measured by liquid chromatography-mass spectrometry/mass spectrometry-liquid chromatography-mass spectrometry (LC-MS/MS) method, and serum cytokine levels were measured by ELISA method. The results of the study revealed that there was no statistically significant difference between the groups in terms of serum 25-D levels. However, serum 1.25-D level was higher in both E. coli and Coronavirus groups compared to the control group. TNF-α level did not differ in the E. coli group compared to the control group but it was lower in the rotavirus, coronavirus and C. parvum groups. While the concentrations of IFN-γ, IL-1β, IL-2, IL-4 and IL-17 were statistically higher in the E. coli group than in the control group, no significant difference was found in the other groups. While the IL-5 concentration increased in the E. coli group and decreased in the C. parvum group compared to the control group, however, there was no statistical difference in the other groups. It was determined that IL-6 concentration did not differ significantly in the E. coli and Coronavirus groups compared to the control group, but it was statistically lower in the Rotavirus and C. parvum groups compared to the control group. While IL-10 concentration was significantly lower in the Rotavirus group than in the control group, no significant difference was found in the other groups. IL-12 concentration increased in E. coli, Rotavirus and Coronavirus groups compared to the control group while there was no significant change in the C. parvum group. There was no statistically significant difference between the groups in terms of IL-13 concentrations. It was concluded that serum cytokines and vitamin D levels differ according to the type of etiological factor in calf diarrhea and that vitamin D may contribute to the development of the immune response in calf diarrhea. Key words: Neonatal Calf, Diarrhea, Cytokine, Vitamin D