EFFECT OF TEMPERATURE OF WET EXTRUSION ON THE NUTRITIONAL-VALUE OF FULL-FAT SOYBEANS FOR BROILER-CHICKENS

1. An experiment was conducted to determine the temperature for wet ex trusion of full-fat soyabeans (FFS) needed to produce maximum chicken performance. 2. FFS were either unprocessed or extruded at 5 different temperatures (118 degrees, 120 degrees, 122 degrees, 126 degrees and 140 degrees C) in a wet extruder. Diets were prepared with the differe nt FFS, and a diet prepared with soyabean meal (SBM) was included as a control. The 7 experimental diets were fed to individual groups of 40 chickens each, for a period of 35 d. Trypsin inhibitor activity (TIA) , urease activity (UA), and protein solubility in potassium hydroxide (PS) were measured in all FFS and in the SBM. 3. Diets prepared with r aw FFS and FFS extruded at 118 degrees and 120 degrees C resulted in s ignificantly lower body weights and in pancreatic hypertrophy; maximum growth rate was obtained with FFS extruded at 122 degrees and 126 deg rees C, while minimum pancreas weight was seen in chickens fed FFS ext ruded at 140 degrees C. 4. Although TIA, UA, and PS all decreased with increasing temperature of extrusion, TIA provided the best prediction of the feeding value of soyabeans for chickens.