ISSUE FOCUS FEED & ADDITIVE MAGAZINE April 2025 39 able energy (ME) estimates in their 2012 ingredient matrix tables. In visiting with members of NRC's committee, they elected to use the Noblet NE equations (Noblet and van Milgen, 2004) over other systems. Thus, the calculated NRC (2012) NE of SBM relative to corn is stated at 78% (2,087 kcal/kg). With additional FGAA becoming economically feasible for use in swine and poultry diets, considerable work on using these newer FGAA (L-valine (Val), L-isoleucine (Ile) and L-Arginine (Arg) has been completed. A recent trial was conducted by Cemin et al. (2020) evaluated varying levels of SBM from very low to high diets supplemented with FGAA to meet NRC (2012) recommendations. The authors used NRC (2012) NE estimates to calculate total dietary NE and then calculate caloric efficiency (CE, calculated by multiplying total feed intake × energy content of the diet (kcal/kg) and dividing by total gain). In evaluating all their data points, they estimated the NE of SBM at 105% of corn and 120% or higher using different methods. In reviewing the trials suggesting NE value of SBM is higher that provided by corn, we have concerns with the trial designs. Authors balanced AA ratios to lysine down to histidine, but did not account for phenylalanine, tyrosine nor arginine in their formulation. Additionally, they conclude all the change in CE is due to NE of SBM alone, which is doubtful. We theorized that the NE of SBM is not greater than that of corn and that some essential amino acids (EAA) may have been limiting or in previous work conducted. We designed our trial to look at varying levels of SBM within the proven EAA to lysine ratios to be non-limiting on growing-finishing pig performance. MATERIAL AND METHODS A total of 2,153 pigs (PIC 337 × 1050; initially 28.8± 0.47 kg) were used in a 112-d growth trial. The study was conducted in two barns at a commercial research finishing site in southwest Minnesota. The barns were naturally ventilated and double-curtain-sided with totally slatted floors. Each pen was equipped with a 5-hole stainless steel dry self-feeder and a bowl waterer for ad libitum access to feed and water. All diets were manufactured at the Hord Farms West Feed Mill (Pipestone, MN) and were in mash form. Daily feed additions to each pen were accomplished using a robotic feeding system (FeedPro; Feedlogic Corp., Wilmar, MN) that recorded feed deliveries for individual pens. The protocol used in this experiment was approved by the Kansas State University Institutional Animal Care and Use Committee. Pigs were housed in mixed gender pens with 26 or 27 pigs per pen across two barns. Pens of pigs were blocked by initial BW and allotted to 1 of 4 dietary
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