Abstract: 【Objective】 The nutritional value of 10 soybean meal (SBM) samples was systematically evaluated by a combination of wet chemical,in vitro and in vivo methods to analyze the correlation between their effective energy values and nutrient content,rumen fermentation parameters and gas production,and construct a prediction model for the related effective energy values. 【Method】 The conventional nutrient composition of 10 soybean meal samples was examined by wet chemical method,The in vitro fermentation indicators of the samples were determined based on the in vitro method and the effective energy values of the feedstuffs were determined by in vivo method. The predictive model for effective energy values of soybean meal was established on the above measurement results.Thirty-six 16-month-old Simmental hybrid cattle were selected and divided into one control group and five treatment groups,with six cattle in each group.They were fed by tethered feeding.The experiment lasted for 42 days,with each 21-day period as one stage,including a 16-day pre-feeding period and a 5-day sampling period. 【Result】 The results obtained revealed that the neutral detergent fibre (NDF) content of 10 soybean meal samples ranged from 17.28% to 33.35%,the crude protein (CP) content ranged from 40.18% to 50.81%,and the dry matter (DM) content ranged from 88.01% to 95.40%.The acetic acid (Ace) content produced by in vitro fermentation of soybean meal ranged from 79.23 to 88.03 mmol/L,the propionic acid (Pro) content ranged from 40.45 to 48.69 mmol/L,and the butyric acid (But) content ranged from 23.32 to 38.06 mmol/L.The digestible energy (DE) of soybean meal ranged from 12.13 to 16.67 MJ/kg,and the metabolisable energy (ME) ranged from 10.01 to 13.97 MJ/kg.The analysis of correlation between the effective energy value and various indicators showed that butyric acid,total volatile fatty acids (TVFA) and gas production (GP_{3 h} and GP_{9 h}) were the four indicators most highly correlated with the effective energy value (r were 0.669,0.687,0.687 and 0.724,respectively).The final predictive model for the effective energy value of soybean meal was established as follows:DE＝－14.904＋0.0857 TVFA＋0.351 Pro＋0.0912 Ace－0.845 Ibut－0.0381 GP_{9 h}(R²＝0.755)；ME＝－4.039－0.125 GP_{9 h}＋0.0343 TVFA＋0.125 GP_{3 h}＋0.0328 But－0.270 Pro(R²＝0.648). 【Conclusion】 The results of this study indicated that the effective energy value of soybean meal was highly correlated with its in vitro fermentation and gas production indicators.A preliminary prediction model for the effective energy value of soybean meal was constructed based on factors such as butyric acid,total volatile fatty acids,and gas production,which could provide reference for the efficient utilization of soybean meal.

Key words: soybean meal; nutritional value assessment; effective energy value; in vitro fermentation