Efficacy and limitations of different approaches to anticipate the diagnosis of pregnancy in cattle oleh M.P. Palhão, C.R.B. Guimarães, J.F.J.F.M. Lima, M.R. Mendonça, C.A.C. Fernandes, J.P. Neves, J.A.D. Garcia, M.M. Gioso, M.A. Miglino, J.H.M. Viana