Study On Solid-state Fermentation Conditions Of Soybean Meal And Its Application On Weaned Pigs

In this research, the fermentation conditions of solid-state fermentated soybean meal (FSBM) were optimized, and concentration of DE and ME, apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) of FSBM were determined; then the effects of replacing soybean meal (SBM) with FSBM on growth performance, apparent total tract digestibility (ATTD) of nutrients and serum indexes for weaned piglets were further studied. There were four parts in this study:(1) An experiment was conducted to explore a new strategy of co-inoculating Bacillus subtilis MA139with Streptococcus thermophilus and Saccharomyces cerevisiae as starter strains to produce FSBM. Effects of initial moisture content, incubation temperature, incubation duration, sugar addition, and protease supplementation on the nutritional quality of FSBM were investigated. The optimal parameters for solid-state fermentation of SBM were initial moisture content,40%; sugar addition,0.5%; protease supplementation,0.3%; neutral protease to acid protease ratio,3:1; incubation temperature,40℃; incubation duration,5d.(2) Twenty-four barrows (Duroc x Landrace×Yorkshire, initial BW of32.2±1.7kg) were randomly allotted to1of4diets with6replicates per diet. A corn basal diet and3diets based on a mixture of corn and1of3soybean products (SBM, FSBM, and Suprotein(?)(a commercially available FSBM)) were formulated and the DE and ME contents were determined by the difference method. The DE and ME of SBM was16.94and16.56MJ/kg DM. The DE and ME of FSBM was17.04and16.51MJ/kg DM. The DE and ME of Suprotein(?) was17.12and16.54MJ/kg DM. The results showed that there were no differences in DE and ME between SBM and either FSBM product (P>0.05).(3) Eight barrows (initial BW of26.8±1.5kg) were fitted with ileal T-cannulaes and used in a replicated4×4Latin square design to determine the AID and SID of amino acids in SBM, FSBM and Suprotein(?). Three corn-starch-based diets were formulated using each of the3soybean products as the sole source of AA. A nitrogen-free diet was also formulated to measure endogenous losses of AA. The results showed that the SID of all AA except arginine and histidine was similar for FSBM and SBM (P>0.05), but Suprotein(?) had greater (P<0.05) SID of most AA except lysine, aspartate, glycine and proline than FSBM.(4) An experiment was conducted to evaluate the effects of replacing soyben meal with FSBM and Suprotein(?) in identical DE and SID of AA diet on performance, ATTD of nutrients and serum indexes of weaned piglets. A total of144piglets (initial BW of8.8±1.2kg) were blocked by weight and fed1of4diets including a control diet with24%SBM as well as diets containing6%and12%FSBM or12%Suprotein(?) added at the expense of SBM. During d15to28, replacing SBM with6%FSBM significantly improved ADG and ADFI (P<0.05) for weaned piglets. During the overall experiment, ADG of piglets fed diets containing6%FSBM was significantly greater (P<0.05) than that of piglets fed SBM. There was significant effect of replacing SBM with FSBM on ATTD of dry matter. Furthermore, ATTD of dry matter was significantly higher in12%FSBM group compared with the6%FSBM group. Compared with SBM group, the6%FSBM group had decreased diarrhea rate (P <0.10). Serum indexes of weaned piglets were not affected by dietary treatments. In conclusion, fermentation with the new strategy did not affect the energy content or the AID and the SID of AA in SBM. However, inclusion of6%FSBM in diets fed to weaned piglets improved performance and ATTD of dry matter and decreased diarrhea rate after weaning likely as a result of better nutritional status and reduced immunological challenge.