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Data from 129,575 Nellore cattle born between 1993 and 2006, belonging to the Jacarezinho cattle-raising farm, were used to estimate genetic parameters for scrotal circumference measured at 9 (SC9), 12 (SC12), and 18 (SC18) mo of age and testicular volume measured at the same ages (TV9, TV12, and TV18) and to determine their correlation with weaning weight (WW) and yearling weight (YW), to provide information for the definition of selection criteria in beef cattle. Estimates of (co)variance components were calculated by the REML method applying an animal model in single- and multiple-trait analysis. The following heritability estimates and their respective SE were obtained for WW, YW, SC9, SC12, SC18, TV9, TV12, and TV18: 0.33 ± 0.02, 0.37 ± 0.03, 0.29 ± 0.03, 0.39 ± 0.04, 0.42 ± 0.03, 0.19 ± 0.04, 0.26 ± 0.05, and 0.39 ± 0.04, respectively. The genetic correlation between WW and YW was …