Depleted serum vitamin E concentrations precede left displaced abomasum in early-lactation dairy cows

摘要

Cows with left displaced abomasum (LDA), a costly disease occurring primarily in multiparous dairy cows during early lactation, have been reported to have 40% lower circulating concentrations of vitamin E. It is unknown, however, whether the lower circulating a-tocopherol concentrations precede LDA or remain after LDA. Using a nested case-control design, blood samples taken at d -21, -14, -7, -3, -1, 0, 1, 3, 7, 14, 21, 28, 35, 42, and 49 postpartum from 7 multiparous Holstein cows diagnosed with LDA between d 6 and 32 postpartum and 10 healthy Holstein cows from the same herd were analyzed for serum concentrations of α-tocopherol and indicators of energy and nutrient status and inflammation. In addition to indicators of negative energy balance and inflammation, lower serum a-tocopherol concentrations preceded LDA and persisted after LDA correction. At the last blood sampling before LDA diagnosis, cows had serum a-tocopherol concentrations 45% lower (5.0 ± 0.9 vs. 9.1 ± 0.9 μM) and a-tocopherol to cholesterol molar ratios 39% lower (1.90 ± 0.19 vs. 3.09 ± 0.26) than those of healthy cows. Serum a-tocopherol concentrations remained lower (＜10 vs. ～15 μM) up to d 49 postpartum in cows that had LDA. These findings indicate that lower serum a-tocopherol concentrations are a potential early indicator for the development of LDA in multiparous cows.