Milk choline, alpha-tocopherol and neutrophil chemotaxis in the periparturient dairy

摘要

Lipotropic agents such as choline may be particularly beneficial in view of the changes in adipose and liver metabolism that occur during the transition from late pregnancy to early lactation (Piepenbrink and Overton, 2000). The lowered plasma non-esteri-fied fatty acid (NEFA) levels and NEFA/cholesterol ratio observed in rumen-protected choline (RPC)-supplemented cows at parturition suggests more efficient liver function and improved lipid metabolism in general (Pinotti et al., 2000). Lipid and. lipoprotein metabolism can also influence the availability of other nutrients. For example alpha-tocopherol is primarily transported in plasma by lipoproteins, and is preferentially incorporated into nascent very low-density lipoprotein (Dutta-Roy et al., 1994). Because choline is a vital component of lipoproteins, it is reasonable to postulate that choline availability may influence vitamin E status in the dairy cow. In agreement with this hypothesis, in a previous communication (Pinotti et al., 2000), an improvement in plasma levels of alpha-tocopherol was shown in periparturient dairy cows receiving rumen-protected choline.