Knowing residual feed intake (RFI) early in life of growing cattle represents an interesting opportunity as it would allow both precision feeding and genetic selection. However, measuring RFI is too expensive. Blood plasma biomarkers represent a cost-effective way to predict RFI and identify feed efficient cattle. Previous works have identified candidate RFI plasma parameters that enable differentiation between extreme phenotypes in young bulls. However, their genetic relationships to RFI need to be clarified. The aim of this study is to estimate the genetic parameters of 13 easily measurable plasma parameters identified as biomarkers of RFI in early-fattening young bulls and assess their genetic correlations with RFI. A total of 639 young bulls were fattened in four experimental farms and were fed ad libitum either grass or corn silage-based diet. Metabolites and plasma enzymes were analyzed during the early fattening stage of animals (303 ± 25 days of age) by spectrophotometric methods performed in an autoanalyzer. Wombat software was used to estimate genetic parameters. The plasma parameters significantly correlated with RFI were alanine aminotransferase (0.89 ± 0.26), aspartate aminotransferase (0.50 ± 0.32), creatinine (-0.46 ± 0.28), triglycerides (-0.44 ± 0.32) and total plasma proteins (-0.41 ± 0.36). Among these five plasma parameters, the heritability ranged from 0.15 to 0.34, while the heritability of RFI was 0.21 (± 0.10). These results pave the way for using blood plasma parameters as proxy to implement genomic evaluation of RFI.