A preliminary study on digital quantification of ocular attributes in cattle as potential non- invasive predictors of anemia

Abstract Background Various non-invasive indicators such as ocular attributes have been tested and validated in respect to assessment of anemia and vitamin A deficiency in human medical sciences with promising results. However, regarding veterinary diagnostics/prognostics, there is a paucity of literature for photometric assessment of anemia in cattle. The present preliminary study is the first account of digital quantification of various ocular attributes in cattle (n = 36) carried out with an objective to unearth the potential of these attributes (RGB analysis and morphometry of eye balls, and color of palpebral conjunctiva) as non-invasive predictors of RBC count, hemoglobin (Hb) and packed cell volume (PCV). Results Results showed that green (r = 0.571), blue (r = 0.706), yellow (r = 0.624), black (r = 0.712) and whiteness (r = 0.778) of cattle eye were positively and significantly (P ≤ 0.05) correlated to Hb with an adjusted r-square value of 0.67, indicating 67.0% predictability for overall model. Similarly, red (r= -0.536), green (r= -0.565), magenta (r= -0.409), yellow (r= -0.563), black (r = 0.700) and whiteness (r= -0.805) were highly correlated (P ≤ 0.05) to Hb with a strong overall model predictability of 67.6%. The associations with RBC count were, however, weaker and non-significant (23% predictability). Conclusions It is concluded that various ocular attributes of cattle, particularly blue, yellow, black, whiteness and lightness, could serve as non-invasive indicators of Hb and PCV, assisting in detecting of anemia. The palpebral conjunctiva color chart developed through this preliminary data could function as an on-field point-of-care testing (POCT) tool for predicting Hb and PCV levels in cattle. Future research should involve larger sample sizes and explore additional non-invasive indicators for use in veterinary diagnostics/prognostics.