An automatic eye surface-fundus double imaging system for estimation of vitamin A levels in Japanese Black Cattle

Blood vitamin A levels during fattening have a crucial influence on beef marbling. As an alternative of conventional blood assays, eye imaging method has been raised as a potential non-invasive way to monitor vitamin A levels in cattle. However, current image capture systems merely acquire cattle eye surface images, which cannot adequately reflect the chromatic information of eye retina that indicates vitamin A level changes. Based on previous research, we propose a novel, automatic double imaging system that combined two illuminating system as well as the installation of polarising filters to eliminate eye surface reflection and consequently, obtain clear fundus images. This greatly facilitated subsequent image processing and feature extraction for vitamin A prediction. The proposed imaging system demonstrated a stronger correlation between vitamin A levels and chromatic features in fundus images than previous systems. An improved classification (accuracy 82%) of vitamin A deficiency level than previous study (56.6%) strongly supports this system's advantage. Being non-invasive cost-effective and rapid, this double imaging system is expected to play an important role in precision livestock farming as well as clinical diagnosis in veterinarian.