Effect of dietary soybean oil and soybean protein concentration on the concentration of digestible amino acids in soybean products fed to growing pigs

SK Cervantes-Pahm, and HH Stein. 2008. Journal of Animal Science. 86:1841-1849.

15-Dec-2009 (16 years 5 months 23 days ago)
The apparent ileal digestibility (AID) of AA by growing pigs is increased if oil is added to the diet. Standardized ileal digestibility values (SID) for CP and AA take into account the AA contributions of endogenous origins, and values for SID are more accurate estimates of the digestibility of AA in a feed ingredient compared with values for AID. However, there is limited information about the effect of dietary oil on the SID of AA in soybean products fed to pigs. The objective of this experiment was to measure the effect of oil addition to SBM and SPC on AID and SID of CP and AA by growing pigs and to compare these values to the AID and SID for CP and AA in FFSB.

In the present study commercial sources of FFSB (FFSB-CV), SBM, and SPC, and of a new high-protein variety of FFSB (FFSB-HP) were used. Four diets were prepared using each soybean product as the sole source of CP and AA in 1 diet. Two additional diets were formulated by adding soybean oil (7.55 and 7.35%, respectively) to the diets containing SBM and SPC. A nitrogen-free diet was also used to measure basal endogenous losses of CP and AA. The 2 sources of FFSB were extruded at 150°C before being used in the experiment. Seven growing barrows (initial BW = 26.2 kg) were prepared with a T-cannula in the distal ileum and allotted to a 7 x 7 Latin square design. Ileal digesta were collected from the pigs on d 6 and 7 of each period. All digesta samples were lyophilized and analyzed for DM, CP, AA, and chromium, and values for AID and SID of CP and AA were calculated.

The addition of oil improved (P < 0.05) the SID of most indispensable AA in SBM and SPC. The SID for 6 of the indispensable AA in FFSB-HP were greater (P < 0.05) than in FFSB-CV, and the SID for all indispensable AA except Met was greater (P < 0.05) in FFSB-HP than in SBM. However, the SID for most AA in FFSB-HP was similar to SBM with oil and SPC, but these values were lower (P < 0.05) than in SPC with oil.

It is concluded, that the addition of oil improved the SID of most AA in SBM and SPC fed to growing pigs, and the SID of AA in FFSB-HP were greater than in SBM and similar to the SID of AA in SBM with oil and in SPC.