PSVI-25 Bioforensics: what can be learned from near infrared spectroscopy of cattle nasal surface tissue?

Forensic scientists have long recognized the value of unique patterns in human fingerprints as a means of identification. Recently, biochemical information associated with sweat and other exudates from human skin have also proved to be informative. Characteristics such as sex, age, and tobacco or drug use can be gleaned from fingerprints. Like human fingerprints, cattle nose prints are also individually unique, and their nasal surface tissue is covered by similar exudates. We hypothesized that cattle nasal surface chemistry will be influenced by internal homeostasis or departure therefrom. Our objective was to apply portable near infrared (NIR) spectroscopy to examine cattle nasal surface chemistry in groups with known or expected physiologic, and or metabolic differences. Near infrared spectra (1000-2500 nm) were obtained with an ASD Field Spec Pro equipped with a fiber optic probe from: 1) mature free ranging beef cows (n = 25) in fall of 2023 and 2024, 2) growing beef calves (n = 7 steers, 7 heifers) at two ages (3 and 7 months), and 3) weaned beef calves (n = 15) before and after transportation (~6 hours) from a pasture to a dry lot facility. Nasal plate NIR spectra were collected by placing the probe directly on the nasal surface tissue during routine health or management-oriented working events. Differences in spectra between groups were determined by principal component and partial least squares (PLS) regression procedures. Statistical significance was set at P < 0.05. Results for PLS predicted group membership are presented in Table 1. In all 3 studies, nasal surface tissue chemistry (as indicated by NIR spectra) was different between the treatment groups and can be attributed to differences in nutritional state, sex, or stress response. Cattle nasal surface chemistry is thus indicative of internal metabolic and physiologic processes. Future studies will be designed to discern individual animal differences due to pre-clinical respiratory infections and or feed efficiency.