... marked decline atcalving in serum concentrations of vitamins Aand E, and in Zn in agreement with earlier re-ports (Johnston & Chew 1984, Goff & Stabel1990, Weiss et al. 1990, Xin et al. ... formation, changes in dry matter intake, and ruminal metab-olism around calving. Decreased levels of vitamins A and E, and of Zn at calving mighthave negative implications for the functions of the immune ... werecollected in the morning, using Vacutainer®tubes (Becton Dickinson Vacutainer Systems,Meylan, France), one month before estimatedcalving, at calving (within 24 hours after calv-ing) and one...