NIR Aquaphotomics Milk Analysis Method Detects Johne’s Disease in Dairy Cows

New Milk-Based Diagnosis for Dairy Cattle

A team of scientists led by S. Behdad, R. Massudi, A. Pakdel, and colleagues has introduced a novel method to diagnose Paratuberculosis—also known as Johne’s disease (JD)—in dairy cattle using milk samples. Published in Scientific Reports (2025), the study leverages near-infrared spectroscopy (NIRS) and aquaphotomics to detect biochemical changes associated with the disease (1).

The research involved collecting milk samples from dairy cows at two stages: 60 days before and 100–200 days after calving. Animals were classified as positive or negative for JD based on three consecutive enzyme-linked immunosorbent assay (ELISA) tests of blood plasma and milk. This classification provided a robust reference for the spectroscopic analysis (1).

NIR Aquaphotomics Milk Analysis Method Detects Johne’s Disease in Dairy Cows © By Viktor -chronicles-stock.adobe.com

NIR Spectroscopy Meets Aquaphotomics

NIRS, was used to monitor subtle molecular changes in milk caused by Paratuberculosis. Aquaphotomics analyzes water molecular structures as sensitive indicators of biochemical changes in biofluids (1).

The combination of NIRS and aquaphotomics enabled researchers to track antibody levels indirectly by observing changes in the water spectral patterns of milk. “Water acts like a biosensor and amplifier,” the study noted, highlighting its ability to detect low-concentration biomarkers (1).

Applied Aquaphotomics

In this study, aquaphotomics was applied to analyze the water molecular structure in milk as a sensitive indicator of Paratuberculosis infection. By focusing on 12 specific water absorbance bands in the near-infrared range (1300–1600 nm), researchers were able to detect subtle perturbations in milk caused by antibodies and other biochemical changes associated with the disease. These water spectral patterns, visualized through aquagrams, acted as multidimensional biomarkers, capturing complex physiological responses in infected versus healthy cows. Using this approach, the team could accurately discriminate between healthy and infected animals, even outperforming traditional ELISA tests on milk samples, demonstrating that water’s spectral behavior reflects the overall state of the biological system (1–3).

High Accuracy Classification

Using chemometrics-based multivariate analysis, including principal component analysis (PCA) for unsupervised classification and quadratic discriminant analysis (QDA) and support vector machine (SVM) for supervised classification, the team achieved remarkable results.

Internal validation showed 100% accuracy for distinguishing healthy from infected animals across both NIR full-range spectra and the 12 water absorbance bands. External validation using blood plasma ELISA results as a reference achieved 100% sensitivity, outperforming milk ELISA tests. The water absorbance bands alone provided highly accurate classification, demonstrating the power of aquaphotomics as a non-invasive diagnostic tool (1).

Implications for Dairy Herd Health

Johne’s disease is a chronic, progressive infection caused by Mycobacterium avium subspecies Paratuberculosis (MAP). It affects intestinal health, milk and meat production, and fertility, resulting in significant economic losses in dairy herds. Traditional diagnostic methods—including ELISA tests, fecal PCR, and bacterial culture—can be time-consuming, invasive, and less sensitive, especially in early disease stages (1).

This study indicates that monitoring milk with NIR spectra and aquaphotomics provides a fast, accurate, and non-destructive alternative. The approach captures both biochemical and water-structural changes in milk, serving as a multidimensional biomarker for antibody presence and disease status (1).

Toward a Sustainable, Non-Invasive Strategy

Behdad and colleagues emphasize that their approach offers an easier sampling method than blood plasma while retaining higher diagnostic accuracy. The long-term goal is to develop a comprehensive, in vivo diagnostic strategy for the four stages of Johne’s disease, contributing to sustainable food production, herd genetic resource preservation, and global health monitoring (1).

References
(1) Behdad, S.; Massudi, R.; Pakdel, A.; et al. Milk NIR Spectroscopy and Aquaphotomics Novel Diagnostic Approach to Paratuberculosis in Dairy Cattle. Sci. Rep. 2025, 15, 19239. DOI: 10.1038/s41598-025-99421-x.

(2) Giovinazzo, S.; Brambilla, M.; Cattaneo, T. M. P.; Lazzari, A.; Bisaglia, C.; Muncan, J.; Tsenkova, R. Aquaphotomics and NIR Water Spectral Patterns in Dairy Production: A Review Exploring Potentials and Challenges. J. Dairy Res. 2024, 91 (3), 249–261. DOI: 10.1017/S0022029924000608.

(3) Tsenkova, R.; Munćan, J.; Pollner, B.; Kovacs, Z. Essentials of Aquaphotomics and Its Chemometrics Approaches. Front. Chem. 2018, 6, 363. DOI: 10.3389/fchem.2018.00363.