β-carotene and vitamin E in the dairy industry: blood levels and influencing factors – a case study in Flanders

Abstract

In this case study performed in Flemish dairy herds, it is shown that lactation stage, farm type (grazing (fresh grass) or zero-grazing) and season are interrelated factors associated with circulating β-carotene (bC) and Vitamin E (VitE) concentrations. The iCheck bC is an easy applicable cow-side test to evaluate a cow’s bC status. One third of the dairy cows in the study had deficiencies in circulating bC and VitE, especially cows in early lactation and cows from zerograzing farms. Fresh grass in the diet could not resolve the early post-partum decline in plasma bC and VitE. However, the bC and VitE statuses of dry cows were significantly better on grazing farms. These findings can help updating antioxidant recommendations since it is clear that there is a need for optimization of antioxidant nutritional management in the Flemish dairy industry in order to feed for optimal dairy cow health.