Metabolic changes in early lactation and impaired reproductive performance in dairy cows Ruurd Jorritsma, Theo Wensing, Theo A.M. Kruip, Peter L.A.M. Vos and Jos P.T.M. Noordhuizen Vet. Res., 34 1 (2003) 11-26 DOI: 10.1051/vetres:2002054