291 An evaluation of soybean meal inclusion rate in pigs fed from wean to market

Abstract

Abstract Soybean meal (SBM) supply may result in decreased relative costs of SBM compared with other ingredients. Net energy of SBM closer to the NE of corn has been reported which may increase its relative value in formulations (Boyd and Gaines, 2023). To evaluate the effect of SBM level in two common diet formulation strategies, Corn-DDGS-SBM (DDGS) or Corn-SBM (SBM) in wean-to-market pigs (WTM). A total of 540 pigs (PIC X Duroc, 18 d of age, 5.3 kg) were weaned and blocked by body weight (BW) and sex for allocation. Six dietary treatments were assigned to 90 pens to give 15 replications per treatment in a randomized complete block design (RCBD). Individual BW for average daily gain (ADG) and pen feed disappearance (ADF) were collected every 2 wk for 18 wk and carcass data were collected at average market weight of 129 kg (18 to 20 wk after placement). The mash diets were formulated to a SID lysine:NE target in 7 phases using current NE estimates for SBM, 2087 Kcal/kg, and to meet or exceed NRC requirements (2012). The NE level used for DDGS was 2,343 Kcal/kg. The treatments consisted of Low (LO), Medium (MED), and High (HI) SBM levels by providing 0.5%, 0.25% and no added lysine (AA) in SBM- or DDGS (30%)-based diets. Data were analyzed using pen as the experimental unit for performance data and the pig as the experimental unit for carcass data. Data were analyzed using the MIXED procedure (SAS Inst. Inc., Cary, NC) and P < 0.05 was considered significant and 0.05 ≤ P < 0.10 considered a tendency. The ADF tended to be less from wk 0 to 18 for pigs fed SBM than DDGS diets. SBM diets increased wk 6 BW and ADG compared with DDGS (P < 0.05). HI and MED SBM additions increased wk 6 BW and wk 0 to 6 ADG vs LO SBM (P < 0.05). SBM diets increased wk 14 and 18 BW, gain to feed ratio (G:F) and ADG compared with DDGS (P < 0.05) except for MED in DDGS diets, which was not different. HI and MED SBM additions increased wk 14 and 18 BW and 0 to 18 wk ADG vs LO SBM (P < 0.05). Carcass data indicated SBM diets increased hot carcass weight by 2 kg, loin depth, back fat and calculated lean weight, compared with DDGS (P < 0.05). LO SBM resulted in more back fat, less loin depth and lean weight compared with the use of HI or MED SBM (P < 0.05). SBM improved growth, feed and caloric conversion, and increased carcass value in high-performance WTM pigs compared with the use of DDGS. MED and HI SBM level tended to improve ADG and carcass characteristics.