Development of universal near-infrared spectroscopy calibrations in feed derived from animal sources

Citation

Jancewicz LJ. 2025. Development of universal near-infrared spectroscopy calibrations in feed derived from animal sources. In Treiber K, Brooks M, D’amato-Anderson J, Nylander J, Eds. Proceedings of the Sixteenth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Oklahoma City, OK.

Abstract

Zoological institutions frequently rely on animal-derived feeds to meet the complex nutritional needs of carnivores and omnivores. These feeds, including fish, vary significantly in moisture, protein, and fat content due to species, season, and handling, yet are rarely tested due to the cost and time required for traditional laboratory analysis. Near-infrared spectroscopy (NIRS) offers a rapid, environmentally safe, non-destructive alternative once robust calibrations are established. Building on prior work demonstrating comparable performance between high-cost and handheld NIRS instruments, we refined our current effort to focus fish, which are easily homogenized for spectral consistency. A total of 256 scans were collected, and 50 samples were analyzed for moisture, protein, crude fat, fiber, and ash. Preliminary principal component analysis (PCA) showed clear separation among fish samples based on fat content, with the first three components explaining 97.13% of the variance in the spectra (Figure 1). In addition to proximate analysis, we will conduct fatty acid analysis on all samples to provide deeper insight into lipid quality. While not included in the initial calibration, fatty acid profiles will be used to explore their potential contribution to future predictive models and to inform zoo nutrition programs where essential fatty acid content is a concern. The finalized calibration will support routine feed quality assessment and improving nutritional precision across zoo collections.

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