Serial non-invasive measurements of dermal carotenoid concentrations in dairy cows following recovery from abomasal displacement.

Maintaining the health of farm animals forms the basis for a sustainable and profitable production of food from animal origin. Recently, the effects of carotenoids on the oxidative status as well as on reproductive and immune functions in cattle have been demonstrated. The present study aimed at investigating dermal carotenoid levels in cattle recovering from abomasal displacement. For this purpose, serial in vivo measurements were undertaken using a miniaturized scanner system that relies on reflection spectroscopy (Opsolution GmbH, Kassel, Germany). In a first trial, repeated measurements of dermal carotenoid concentrations were performed on the udder skin of healthy non-lactating cattle (n = 6) for one month in weekly intervals. In a second trial, in vivo dermal carotenoid concentrations were determined in intervals in 23 cows following surgical treatment of abomasal displacement. The results show that dermal carotenoid concentrations, determined on a weekly basis over a period of one month, showed variations of up to 18% in the healthy individuals kept under constant conditions with respect to housing and nutrition. Repeated measurements during the recovery period following surgical treatment of abomasal displacement resulted in an increase in dermal carotenoid concentrations in 18 of 20 animals with a favourable outcome when compared with results obtained within 12 hours following surgery. The mean increase in dermal carotenoid concentrations in subsequent measurements was 53 ± 44%, whereas levels decreased (mean 31 ± 27%) in cattle with a fatal outcome.These results indicate potential applications for reflection spectroscopy for non-invasive early detection of changes in the dermal carotenoid concentrations as a reflection of the antioxidant status in an animal.