Sereno, J.R.B. et al. 2001. Age and weight estimate on the first breeding in the Brazilian Pantanal heifers. Pesquisa Agropecuaria Brasileira. 36, 12 (Dec. 2001), 1561–1565. DOI:https://doi.org/10.1590/S1678-3921.pab2001.v36.6291.