Thong H T, Liebert F
Institute for Animal Physiology and Animal Nutrition, Georg-August-University Goettingen, Germany.
Arch Anim Nutr. 2004 Apr;58(2):157-68. doi: 10.1080/00039420410001667520.
This study was conducted to evaluate the variability of the efficiency of threonine in different feed proteins for growing pigs. This information is of importance for actual conclusions about threonine requirement within the exponential N-utilization model (Liebert and Gebhardt, 1986) used in our investigations. Wheat (as basal protein), high-protein soybean meal, low-protein soybean meal, rapeseed meal, field bean (Vicia faba), peas (Pisum sativum), corn gluten meal and soybean protein concentrate were used as protein sources. Fifty-six growing barrows (40-65 kg BW) of the genotype Piétrain x (Duroc x Landrace) were randomly allotted to eight N-balance experiments (n = 7). Diets were formulated with two main ingredients (wheat + one feed protein) with threonine as the first limiting amino acid in the mixture which was partly supplemented with crystalline amino acids. Based on N-balance data, the efficiency of threonine was determined in protein mixtures and individual feed proteins. Threonine requirement was calculated depending on efficiency of threonine and level of daily protein deposition. The results from the present studies indicate that the efficiency of threonine in different feed proteins varied in a wide range. Consequently, this factor has to be taken into account for requirement calculations. The threonine requirement depending on daily protein deposition (130, 145 and 160 g) and the efficiency of threonine according to different reference units (g/BW(kg)(-0.67)/d, g/d and % of threonine in the diet) were calculated. The threonine requirement of growing barrows (50 kg BW) corresponding to an average threonine efficiency was 8.52, 9.92 and 11.61 g/d for a daily protein deposition of 130, 145 and 160 g, respectively. The results for a daily protein deposition of 145 or 160 g are in agreement with actual studies and recommendations for threonine supply.
本研究旨在评估不同饲料蛋白质中苏氨酸对生长猪的利用效率的变异性。该信息对于在我们的研究中使用的指数氮利用模型（Liebert和Gebhardt，1986）中关于苏氨酸需求的实际结论具有重要意义。小麦（作为基础蛋白质）、高蛋白豆粕、低蛋白豆粕、菜籽粕、蚕豆（野豌豆）、豌豆（豌豆）、玉米蛋白粉和大豆浓缩蛋白用作蛋白质来源。56头基因型为皮特兰×（杜洛克×长白猪）的生长公猪（体重40 - 65千克）被随机分配到8个氮平衡实验中（n = 7）。日粮由两种主要成分（小麦 + 一种饲料蛋白质）配制而成，苏氨酸是混合物中的第一限制性氨基酸，部分补充了结晶氨基酸。基于氮平衡数据，测定了蛋白质混合物和单一饲料蛋白质中苏氨酸的效率。根据苏氨酸效率和每日蛋白质沉积水平计算苏氨酸需求量。本研究结果表明，不同饲料蛋白质中苏氨酸的效率差异很大。因此，在需求计算中必须考虑这个因素。计算了根据每日蛋白质沉积量（130、145和160克）以及根据不同参考单位（克/体重（千克）（-0.67）/天、克/天和日粮中苏氨酸的百分比）的苏氨酸效率得出的苏氨酸需求量。对于每日蛋白质沉积量为130、145和160克，平均苏氨酸效率下生长公猪（体重50千克）的苏氨酸需求量分别为8.52、9.92和11.61克/天。每日蛋白质沉积量为145或160克的结果与苏氨酸供应的实际研究和建议一致。
