第199期：利用指示剂氨基酸氧化法研究小型犬、中型犬和大型成犬色氨酸需要量

29625248

2019. J. Anim. Sci. 97(8):3274–3285

DOI：https://doi.org/10.1093/jas/skz142

利用指示剂氨基酸氧化法研究小型犬、中型犬和大型成犬色氨酸需要量

James R Templeman, Wilfredo D Mansilla, Lisa Fortener, Anna K Shoveller

在犬的各个生长阶段，色氨酸都是必须氨基酸；尽管生长犬对色氨酸的需要量来源于3个生长试验，但是对成犬维持需要量的仍没有相关试验数据。

本试验通过指示剂氨基酸氧化法研究了3个不同品种成犬的色氨酸需要量。试验选用4头切除卵巢或去势的微型腊肠犬（5.28±0.29kg体重）、4头切除卵巢的比格（9.32±0.41kg体重）、5头去势的拉布拉多猎犬（30.51±2.09kg体重）。试验开始前饲喂14天的色氨酸充足基础日粮（色氨酸含量0.482%，干基）。随后所有犬饲喂色氨酸中度缺乏日粮2天（色氨酸含量0.092%，干基），然后将犬随机分至7种日粮处理，日粮色氨酸水平分别为0.092、0.126、0.148、0.182、0.216、0.249、0.283%（干基），所有犬经过所有色氨酸水平处理。试验日粮饲喂两天后，犬经过独立的指示剂氨基酸氧化试验。总饲料量分成相同的13份；在第6餐，日粮中额外添加L-[1-13C]-苯丙氨酸（9.40mg/kg体重），随后的每顿日粮中添加L-[1-13C]-苯丙氨酸（2.4mg/kg体重）。通过呼吸样品中的丰度测量同位素稳态下13-CO2的总产量，通过间接侧热法检测CO2总产量。通过两相线性回归模型测定色氨酸的维持需要量和95%置信区间。

微型腊肠犬、比格犬、拉布拉多犬的平均色氨酸需要量为0.154、0.218、0.157%（干基），95%置信区间上限为0.187、0.269、0.204%（干基）。总之，比格犬色氨酸需要量高于拉布拉多和微型腊肠犬，并且均高于NRC和AAFCO的现有推荐值。

Tryptophan requirements in small, medium, and large breed adult dogs using the indicator amino acid oxidation technique

James R Templeman,  Wilfredo D Mansilla,  Lisa Fortener, Anna K Shoveller

Tryptophan (Trp) is an indispensable amino acid(AA) for dogs of all life stages; however, although Trp requirements for growing dogs are derived from 3 dose–response studies, there are no empiricaldata on Trp requirements for adult dogs at maintenance. The study objective was to determine Trp requirements of adult dogs of 3 different breeds using the indicator amino acid oxidation (IAAO) technique. Four spayed or neutered Miniature Dachshunds (5.28 ± 0.29 kg BW), 4 spayed Beagles (9.32 ± 0.41 kg BW), and 5 neutered Labrador Retrievers (30.51 ± 2.09 kg BW) were used. After a 14-dadaptation to a Trp-adequate basal diet (Trp = 0.482% dry matter), all dogs were fed a mildly Trp-deficient diet for 2 d (Trp = 0.092% dry matter) before being randomly allocated to receiving 1 of 7 concentrations of Trp supplementation (final Trp content in experimental diets was 0.092, 0.126,0.148, 0.182, 0.216, 0.249, and 0.283% dry matter) and all dogs received all Trp treatments. After 2-d adaptation to the experimental diets, dogs underwent individual IAAO studies. Total feed was divided in 13 equal meals; at the sixth meal, dogs were fed a bolus of L-[1-13C]-Phenylalanine (Phe) (9.40 mg/kg BW), and thereafter, L-[1-13C]-Phe was supplied (2.4 mg/kg BW) with every meal. Total production of 13CO2 during isotopic steady state was determined by enrichment of 13CO2 in breath samples and total production of CO2 measured using indirect calorimetry. The maintenance requirement for Trp and the 95% confidence interval (CI) were determined using a 2-phase linear regression model. Mean Trp requirements were estimated at 0.154, 0.218, and 0.157%(dry-matter) for Dachshunds, Beagles, and Labradors, respectively. The upper 95% CI were 0.187, 0.269, and 0.204% (dry-matter) for Dachshunds, Beagles, and Labradors. In conclusion, estimated Trp requirements are higher for Beagles compared with Labradors or Dachshunds, and all estimated requirements are higher than those currently recommended by the NRC and AAFCO.

翻译：上海亘泰    转自：猪营养国际论坛