Skin carotenoid levels in lactating dairy cows as measured using multiple spatially resolved reflection spectroscopy.

This research communication describes a pilot study measuring skin carotenoid levels of lactating dairy cows. Carotenoids are natural antioxidants, involved in cell communication and immune function, protecting against oxidative stress. They are precursors of vitamin A, important for reproduction efficiency, growth and male fertility. Therefore, easy-to-use, inexpensive methods to measure carotenoids in cattle would provide interesting data for farmers to monitor the health and nutritional status of their herds. In this study, we used a commercially available sensor based on multiple spatially resolved reflection spectroscopy (MSRRS), intended for human use, to measure the carotenoid content in bovine skin in three research herds in France, Ireland and Scotland. Carotenoid levels were measured by applying the sensor to the teat barrel, avoiding pigmented areas of skin. Mean sensor values differed significantly between herds and between diets, with pasture-based animals showing significantly higher carotenoid levels. Our results suggest that MSRRS can be used to accurately to measure skin carotenoids in cows. However, further calibration in bovines is needed to improve of the accuracy of the MSRRS sensor in cattle.