Two experiments were conducted to determine requirements of tryptophan (Trp) for growing pigs fed low protein diets supplemented with crystalline amino acids (CAA). A total of 360 cross-bred (Duroc×Landrace×Large white) growing pigs [(24.16±2.35) kg, experiment 1] or 360 cross-bred (Duroc×Landrace×Large white) growing pigs [(23.60±2.17) kg, experiment 2] were allotted to 6 treatments with 6 replicates in each treatment and 10 growing pigs in each replicate. In experiment 1, the treatments consisted of a corn and soybean meal control diet meeting the nutrient requirements of swine (NRC, 1998) and five test diets with the same low protein content (4% reduction) and five different Trp levels (0.131%, 0.146%, 0.161%, 0.176% and 0.191%, respectively) supplemented with CAA. In experiment 2, a control diet was the same as that in the experiment 1, and five test diets had the same low protein content (4% reduction) and five different Trp levels (0.141%, 0.150%, 0.159%, 0.170%, and 0.181%, respectively). The results showed that no adverse effects on growth performance were found in growing pigs fed the low protein (4% reduction) diets with CAA supplementation. The results of broken line model and quadratic regression analysis indicated that to achieve maximum growth performance in growing pigs, 0.146% Trp in the low protein (4% reduction) diet with CAA supplementation was necessary, but not greater than 0.152%, and TDLys∶ TDTrp = 100∶（17.6 to 18.3） was a suitable scope. The results indicate that feeding a low protein (4% reduction) diet, optimum growth performance of growing pigs (20 to 50 kg) will be obtained if the diet provides 0.146% Trp, as well as 0.83% ileum true digestible lysine.［Chinese Journal of Animal Nutrition, 2011, 23（10）：1669 -1676］
WANG Rongfa,LI Min,HE Xi,YI Xuewu,YANG Qiang,TANG Yanjun,QIAO Shiyan,ZHANG Shirui
. Tryptophan Requirements of Growing Pigs Fed Low Protein Diets[J]. Chinese Journal of Animal Nutrition, 2011
, 23(10)
: 1669
-1676
.
DOI: 10.3969/j.issn.1006-267x.2011.10.005
［1］RUSSELL L E, CROMWELL G L, STAHLY T S. Tryptophan, threonine, isoleucine and methionine supplementation of a 12% protein, lysine-supplemented, corn-soybean meal diet for growing pigs[J]. Journal of Animal Science, 1983, 56(5):1115-1123.
[2]WAHLSTROM R C, LIBAL G W, THALER R C. Efficacy of supplemental tryptophan, threonine, isoleucine and methionine for weanling pigs fed a low-protein, lysine-supplemented, corn-sunflower meal diet[J]. Journal of Animal Science, 1985, 60(3):720-724.
[3]MYER R O, BRENDEMUHL J H, BARNETT R D. Crystalline lysine and threonine supplementation of soft red winter wheat or triticale, low-protein diets for growing-finishing swine[J]. Journal of Animal Science, 1996, 74(3):577-583.
[4]FIGUEROA J L, LEWIS A J, MILLER P S, et al. Growth, carcass traits, and plasma amino acid concentrations of gilts fed low-protein diets supplemented with amino acids including histidine, isoleucine, and valine[J]. Journal of Animal Science, 2003, 81(6):1529-1537.
[5]TREVISI P, MELCHIOR D, MAZZONI M, et al. A tryptophan-enriched diet improves feed intake and growth performance of susceptible weanling pigs orally challenged with Escherichia coli K88[J]. Journal of Animal Science, 2009, 87(1):148-156.
[6]GUZIK A C, MATTHEWS J O, KERR B J, et al. Dietary tryptophan effects on plasma and salivary cortisol and meat quality in pigs[J]. Journal of Animal Science, 2006, 84(8):2251-2259.
[7]LE FLOC’H N, MELCHIOR D, SVE B. Dietary tryptophan helps to preserve tryptophan homeostasis in pigs suffering from lung inflammation[J]. Journal of Animal Science, 2008, 86(12):3473-3479.
[8]LI Y Z, KERR B J, KIDD M T, et al. Use of supplementary tryptophan to modify the behavior of pigs[J]. Journal of Animal Science, 2006, 84(1):212-220.
[9]GUZIK A C, SOUTHERN L L, BIDNER T D, et al. The tryptophan requirement of nursery pigs[J]. Journal of Animal Science, 2002, 80(10):2646-2655.
[10]BURGOON K G, KNABE D A, GREGG E J. Digestible tryptophan requirements of starting, growing, and finishing pigs[J]. Journal of Animal Science, 1992, 70(8):2493-2500.
[11]张华伟,尹靖东,周玄.限饲和自由采食条件下色氨酸对断奶仔猪血清IGF-1浓度的影响[J].中国畜牧杂志, 2006 (23):19-22.
[12]EDER K, NONN H, KLUGE H, et al. Tryptophan requirement of growing pigs at various body weights[J]. Journal of Animal Physiology and Animal Nutrition, 2003, 87(9/10):336-346.
[13]GUZIK A C, SHELTON J L, SOUTHERN L L, et al. The tryptophan requirement of growing and finishing barrows [J]. Journal of Animal Science, 2005, 83(6):1303-1311.
[14]唐茂妍,陈旭东,梁富广,等.生长猪低蛋白质饲粮可消化赖氨酸、蛋氨酸+胱氨酸、苏氨酸、色氨酸平衡模式的研究[J].中国畜牧杂志,2008,20(4):397-403.
[15]苏有健,李德发,邢建军,等.在低蛋白质饲粮中添加色氨酸对仔猪生产性能及血清游离氨基酸和尿素氮的影响[J].中国畜牧杂志,2005,41(1):26-29.
[16]尹慧红,张石蕊,孙建广,等.不同净能水平的低蛋白质饲粮对猪生长性能和养分消化率的影响[J].中国畜牧杂志,2008,44(13):25-28.
[17]YI X W, ZHANG S R, YANG Q, et al. Influence of dietary net energy content on performance of growing pigs fed low crude protein diets supplemented with crystalline amino acids[J]. Journal Swine Health Producation, 2010, 18(6):294-300.
[18]FIGUEROA J L, LEWIS A J, MILLER P S, et al. Nitrogen metabolism and growth performance of gilts fed standard corn-soybean meal diets or low-crude protein, amino acid-supplemented diets[J]. Journal of Animal Science, 2002, 80(11):2911-2919.
[19]BELLEGO L, MILGEN L V, NOBLET J, et al. Effect of high temperature and low-protein diets on the performance of growing-finishing pigs[J]. Journal of Animal Science, 2002, 80(3):691-701.
[20]张华伟,尹靖东, 周玄.限饲和自由采食条件下色氨酸对仔猪生长性能和血清尿素氮的影响[J].养猪,2006 (1):1-3.
[21]ETTLE T, ROTH F X. Specific dietary selection for tryptophan by the piglet[J]. Journal of Animal Science, 2004, 82(4):1115-1121.
[22]JANSMAN A J M, VAN DIEPEN J Th M, MELCHIOR D. The effect of diet composition on tryptophan requirement of young piglets[J]. Journal of Animal Science, 2010, 88(3):1017-1027.
