| In this study, the nutrient content of different degrees of mildewed soybean meal (SBM)were analyzed. Further more, the nutritional value of mildewed SBM was evaluated by determining the availability of dry material (DM),crude protein (CP), amino acid (AA) and gross energy (GE) using the Sibbald true metabolizable energy method (TME) and the degradability of dry material (DM) and crude protein (CP) in rumen using nylon bay techno logy. The results were as follows: Experiment 1: Evaluation by chemical method.With the increasing of the mould content in SBM from 2 thousand per gram to 140 thousand per gram , water content of SBM increased extremely significantly (P<0.01), CP% had little change, ether extract (EE) content and protein solution (PS) decreased extremely significantly (p<0.01), total amino acid content decreased obviously, among them, Met Lys, Ala and He decreased by more than twenty percentage. GE of SBM did not decrease significantly (p<0.05) until mould content in SBM was higher than 80 thousand per gram. Experiment 2:Evaluation by Sibbald true metabolizable energy methodAvian adult cook was selected to study the nutrient availability and the metabolizable energy value of mildewed SBM. The results indicated as follows:with the increasing of mould contend in SBM from 2 thousand per gram to 30 thousand per gram, the availability of DM and CP showed a little change (P>0.05);When mould contend added up to 80 thousand per gram, the availability of DM and CP decreased, but the difference was not significant;When mould content added up to 140 thousand per gram, the availability of DM and CP decreased extremely significantly (P<0.01) or significantly (P<0.05).With the increasing of mould in SBM, the average availability of total amino acid and essential amino acid decreased, only after mould Content in SBM was over 80 thousand per germ, the availability ofamino acid decreased extremely significantly (P<0.01),.among them, the availability of Ala Met Val and Cys decreased by more than 15 percentage.Different from other nutrients. Mould had a little effect on metabolizable energy. Experiment 3: Evaluation by nylon bag methodTwo yellow cattle with cannulas were used for the measure of DM and CP digradabilities of mildewed SBM in the rumen with nylon bag technology. The results showed as follows: when mould content in SBM was below 80 thousand per gram,DM and CP digradabilities of 24h in the rumen showed a little change , but the difference among the former four group was not significant (p>0.05);When mould content add up to 140 thousand per gram, DM and CP digradabilities decreased sharply, the difference between the fifth group and the former three group was significant (P<0.05). Experiment 4: the effect of heat damage of mildew on the nutritional value of SBMContinuously heat treating at 85 and 115 damaged obviously the nutritional value of SBM (mould content 2 thousand per gram) and mildewed SBM (mould content 80 thousand per gram). Heated at 85 , PS of SBM and mildewed SBM decreased extremely significantly (P<0.01);Heated at 115 , the metabolizable energy ,GE and average availability of total amino acid of SBM and mildew SBM decreased significantly (P<0.05) .PS , the availability of CP, average availability of essential amino acid and the availability of DM decreased extremely significantly. (P<0.01) Experiment 5: The effect of fibre on endogenous amino acid excretionThe level of fibre in N-free diets had great effect on excretion of endogenous amino acid in wasters. With the increasing of fibre content in N-free-diets from 2% to 10%. The excretion of endogenous amino acid increased from 523.94mg/roster/48h to 650.74kg/ roster /48h.Among them .the excretion of Lys, Pro, Gla and Ser increased extremely significantly (P<0.01).The above results suggested that mildew lowered nutrient content, decreased nutrient availability and metabolizable energy in SBM.With theincreasing of mould content in SBM, damage to the nutritional value of SBM would deteri...
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