Economic impact of value added production as based on Texas A&M Ranch to Rail data

This experiment utilized steer data from the 1997--1998 Texas A&M Ranch to Rail program (N = 889). The response variable, net income (NET), was analyzed for coded preconditioning traits (class variables) in an analysis of variance (R2 = 0.05) and a simple regression analysis for feedyard and carcass characteristics (covariables) produced an R2 of 0.90. All class and covariables were combined in a regression analysis (R2 = 0.92). Models of covariables were evaluated with the use of a stepwise regression analysis. Preweaning implant (PREIMP) (P < 0.0003), preweaning external parasite control (PREEXT) (P < 0.05), and preweaning vaccination (PREVACC) (P < 0.007) yielded expected means that indicated benefits of PREIMP and PREEXT were not realized by NET, but PREVACC had a positive return in NET by reducing feedyard medicine costs. From the stepwise analysis, the single best predictor of NET was marbling score (MARB) (R2 = 0.42). However, MARB was not important when the best two-variable model which showed hot carcass weight (HCW) and yield grade (YG) as most significant (R2 = 0.46). Stepwise regression to higher order models indicated the eight-variable model with kidney pelvic heart fat (KPH), feedyard arrival weight (INWT), dressing percentage (DP), value assigned entering the feedyard (VALCWT), medicine costs (NED), total feed costs (TOTFDCOS), HCW, MARB, and YG produced the best results with the lowest number of variables (R2 = 0.88). Positive regression coefficients were seen in DP, MARB, and HCW. The variables INWT, VALCWT, MED TOTFDCOS, and YG received negative regression coefficients. In this study, NET was increased when calves received PREVACC and did not receive PREIMP or PREEXT because there was no carry-over effect for PREIMP and PREEXT. Steers that had a lighter INWT, lower VALCWT, MED, and TOTFDCOS, numerically lower YG, higher DP and MARB, and heavier HCW showed a higher NET. Results indicate steers must have efficient feedyard growth while YG, DP, and HCW are controlled through the feedyard and MARB is selected for genetically to enhance net income in fed steers.