Guzik A C, Southern L L, Bidner T D, Kerr B J
Department of Animal Science, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
J Anim Sci. 2002 Oct;80(10):2646-55.
Five experiments were conducted to determine the true digestible Trp (dTrp) requirement of nursery pigs. Treatments were replicated with four or five pens of five or six pigs each. Pigs were weaned at 21 (Exp. 1, 2, and 5) or 19 d (Exp. 3 and 4), and fed common diets for various times and then experimental diets for 8 (Exp. 1), 13 (Exp. 2 and 3), or 14 d (Exp. 4 and 5). Experiment 1 (160 pigs, initial and final BW of 8.4 and 11.4 kg) evaluated six protein sources low in Trp relative to a positive control diet to identify the protein source to be used in subsequent experiments. The results indicated that a diet with Canadian field peas (CFP) supplemented with Trp resulted in ADG, ADFI, and gain:feed (GF) equal to (P > 0.10) the positive control diet. In Exp. 2, 75 pigs (initial and final BW of 13.2 and 19.2 kg) were fed 1) Trp-deficient diet (0.13% dTrp) with CFP, 2) Diet 1 with added Trp (0.23% dTrp), or 3) positive control diet (0.22% dTrp). Daily gain, ADFI, and GF were decreased (P < 0.01) in pigs fed Diet 1 compared with pigs fed Diets 2 and 3, but ADG, ADFI, and GF were equal (P > 0.10) in pigs fed Diets 2 and 3. Experiments 3 (180 pigs, initial and final BW of 5.2 and 7.3 kg), 4 (120 pigs, initial and final BW of 6.3 and 10.2 kg), and 5 (144 pigs, initial and final BW of 10.3 and 15.7 kg) were conducted to estimate the dTrp requirement of nursery pigs with diets using CFP as a primary protein source. The diets used in Exp. 3, 4, and 5 contained 1.35, 1.19, or 1.01% dLys, respectively, and other amino acids were provided at 105% the ratio relative to Lys. Response variables were ADG, ADFI, GF, and plasma urea N concentrations, and data were analyzed using the broken-line model. The levels of dTrp in the diets for Exp. 3 (Phase I, 5.2 to 7.3 kg) were 0.14, 0.17, 0.20, 0.23, 0.26, and 0.29%. The average dTrp requirement was estimated to be 0.21% (0.24% total Trp). The levels of dTrp in the diets for Exp. 4 (Phase II, 6.3 to 10.2 kg) were 0.13, 0.16, 0.19, 0.22, 0.25, and 0.28%. The average dTrp requirement was estimated to be 0.20% (0.23% total Trp). The levels of dTrp in the diets for Exp. 5 (Phase III, 10.3 to 15.7 kg) were 0.130, 0.155, 0.180, 0.205, 0.230, and 0.255%. The average dTrp requirement was estimated to be 0.18% (0.22% total Trp). These results indicate that the true dTrp requirement is 0.21, 0.20, and 0.18% for Phase I (5.2 to 7.3 kg), II (6.3 to 10.2 kg), and III (10.3 to 15.7 kg) nursery pigs, respectively.
进行了五项试验以确定仔猪可消化色氨酸（dTrp）的真实需要量。试验处理设4或5个重复，每个重复有5或6头猪。仔猪在21日龄（试验1、2和5）或19日龄（试验3和4）断奶，先饲喂普通日粮一段时间，然后饲喂试验日粮8天（试验1）、13天（试验2和3）或14天（试验4和5）。试验1（160头猪，初始体重和末重分别为8.4 kg和11.4 kg）评估了六种色氨酸含量低于阳性对照日粮的蛋白质来源，以确定后续试验中使用的蛋白质来源。结果表明，添加色氨酸的加拿大野豌豆（CFP）日粮的平均日增重（ADG）、平均日采食量（ADFI）和料重比（GF）与阳性对照日粮相当（P>0.10）。试验2中，75头猪（初始体重和末重分别为13.2 kg和19.2 kg）被饲喂：1）添加CFP的色氨酸缺乏日粮（0.13% dTrp）；2）添加色氨酸的日粮1（0.23% dTrp）；3）阳性对照日粮（0.22% dTrp）。与饲喂日粮2和3的猪相比，饲喂日粮1的猪的日增重、ADFI和GF均降低（P<0.01），但饲喂日粮2和3的猪的ADG、ADFI和GF相当（P>0.10）。进行试验3（180头猪，初始体重和末重分别为5.2 kg和7.3 kg）、试验4（120头猪，初始体重和末重分别为6.3 kg和10.2 kg）和试验5（144头猪，初始体重和末重分别为10.3 kg和15.7 kg），以评估以CFP作为主要蛋白质来源的日粮中仔猪对dTrp的需要量。试验3、4和5中使用的日粮分别含有1.35%、1.19%或1.01%的可消化赖氨酸（dLys），其他氨基酸的含量按相对于赖氨酸的比例的105%提供。反应变量为ADG、ADFI、GF和血浆尿素氮浓度，数据采用折线模型进行分析。试验3（第一阶段，体重5.2至7.3 kg）日粮中dTrp的水平分别为0.14%、0.17%、0.20%、0.23%、0.26%和0.29%。估计平均dTrp需要量为0.21%（总色氨酸为0.24%）。试验4（第二阶段，体重6.3至10.2 kg）日粮中dTrp的水平分别为0.13%、0.16%、0.19%、0.22%、0.25%和0.28%。估计平均dTrp需要量为0.20%（总色氨酸为0.23%）。试验5（第三阶段，体重10.3至15.7 kg）日粮中dTrp的水平分别为0.130%、0.155%、0.180%、0.205%、0.230%和0.255%。估计平均dTrp需要量为0.18%（总色氨酸为0.22%）。这些结果表明，第一阶段（体重5.2至7.3 kg）、第二阶段（体重6.3至10.2 kg）和第三阶段（体重10.3至15.7 kg）仔猪的真实dTrp需要量分别为0.21%、0.20%和0.18%。
