Fat digestibility in enzymatically treated soybean meal without and with choice white grease and vegetable oil

An experiment was conducted to measure the digestibility of fat by weanling pigs fed enzymatically treated soybean meal and either soybean oil or choice white grease. Two sources of enzymatically treated soybean meals were used (SBM-1 and SBM-2). These meals are similar with the exception that an emulsifier, lecithin, is included in SMB-2, but not in SBM-1. Soybean meal-1 contained 57.07% CP, 1.44% acidhydrolyzed ether extract (AEE), and 2.30 trypsin inhibitor units (TIU) per mg, and SBM-2 contained 53.60% CP, 3.73% AEE, and 1.50 TIU per mg. Two diets were formulated by mixing cornstarch, sugar, and each source of soybean meal. Two additional diets those were similar to the initial 2 diets with the exception that 6% choice white grease or 6% soybean oil was added to these diets were also formulated. Thirty-two weanling barrows (initial BW: 13.3 ± 0.8 kg) were randomly allotted to the 4 diets with 8 replicate pigs per diet in a 2 × 2 factorial design. Pigs were housed in metabolism cages. Pigs were fed experimental diets for 14 d with total collections of faeces during the final 5 d.

Feed intake and DM output were not different among treatments. The apparent total tract digestibility (ATTD) of DM and GE were not different among treatments regardless of soybean meal and fat source. The ATTD of AEE in SBM-1 and SBM-2 mixed with soybean oil was not different (80.4 and 75.7%, respectively). The ATTD of AEE in SBM-1 and SBM-2 mixed with choice white grease was also not different (80.2% and 79.3%, respectively).

Results indicated that the added lecithin in SBM-2 did not increase fat digestibility in pigs fed diets supplemented with soybean oil or choice white grease.