Zhang Y, Parsons C M, Weingartner K E, Wijeratne W B
Department of Animal Sciences, University of Illinois, Urbana 61801.
Poult Sci. 1993 Dec;72(12):2299-308. doi: 10.3382/ps.0722299.
Two chick growth experiments and a precision-fed cockerel digestibility assay were conducted to evaluate the effect of extrusion and expelling on the nutritive value of conventional (CSB) and Kunitz trypsin inhibitor-free (KFSB) soybeans. In the first experiment, performance of chicks fed CSB or KFSB autoclaved at 121 C was similar to that of chicks fed CSB or KFSB extruded at 138 C. The effect of extrusion temperature on protein quality of the soybeans was evaluated in the second experiment. Eleven corn-soybean diets were formulated to contain one of the following: CSB extruded at 104, 121, 138, or 154 C; KFSB extruded at 104, 121, or 138 C; CSB extruded at 121, 138, or 154 C followed by processing through an expeller; and commercial dehulled solvent-extracted soybean meal (SBM). All diets contained 20% crude protein and the same amount of soybean oil and were fed to chicks from 7 to 21 days of age. The CSB extruded at 104 or 121 C and KFSB extruded at 104 C yielded depressed growth and feed efficiency compared with SBM. Performance of chicks on the other treatments was similar to that of chicks fed SBM. Pancreas weight (as a percentage of BW) decreased as extrusion temperature increased, with the response being greater for CSB. Growth performance was greater and pancreas weights were lower for chicks fed KFSB extruded at 104 or 121 C compared with those of chicks fed CSB extruded at the same temperatures. Expelling improved weight gain and feed efficiency when CSB was extruded at 121 C. A 48-h digestibility assay with cecectomized cockerels indicated that digestibility of amino acids in CSB and KFSB increased as extrusion temperature increased and that digestibilities of amino acids in CSB extruded at 104 or 121 C were lower than those in KFSB extruded at the same temperatures. Results of this study indicated that extrusion of CSB at 138 to 154 C or extrusion of KFSB at 121 to 138 C yields protein quality similar to that of SBM.
进行了两项雏鸡生长试验和一项精确饲喂公鸡消化率测定试验，以评估挤压和压榨对常规大豆（CSB）和无库尼茨胰蛋白酶抑制剂大豆（KFSB）营养价值的影响。在第一个试验中，饲喂121℃高压灭菌的CSB或KFSB的雏鸡的生长性能与饲喂138℃挤压的CSB或KFSB的雏鸡相似。在第二个试验中评估了挤压温度对大豆蛋白质质量的影响。配制了11种玉米-大豆日粮，分别含有以下之一：104、121、138或154℃挤压的CSB；104、121或138℃挤压的KFSB；121、138或154℃挤压后再经压榨机处理的CSB；以及商业去皮溶剂浸出豆粕（SBM）。所有日粮均含有20%的粗蛋白和等量的大豆油，并饲喂7至21日龄的雏鸡。与SBM相比，104或121℃挤压的CSB以及104℃挤压的KFSB导致雏鸡生长和饲料效率降低。其他处理组雏鸡的生长性能与饲喂SBM的雏鸡相似。胰腺重量（占体重的百分比）随着挤压温度的升高而降低，CSB的反应更大。与饲喂相同温度挤压的CSB相比，饲喂104或121℃挤压的KFSB的雏鸡生长性能更好，胰腺重量更低。当CSB在121℃挤压时，压榨提高了体重增加和饲料效率。对去盲肠公鸡进行的48小时消化率测定表明，CSB和KFSB中氨基酸的消化率随着挤压温度的升高而增加，104或121℃挤压的CSB中氨基酸的消化率低于相同温度挤压的KFSB。本研究结果表明，138至154℃挤压CSB或121至138℃挤压KFSB产生的蛋白质质量与SBM相似。
