Excess Levels of ILysine and Threonine in Low Protein, Wheat-based Diets on Serum Amino Acid Concentrations and Performance of Growing Pigs  

作　　者：Adriana Morales JoseLuis Landero Alfonso Araiza Hugo Bernal Willem C. Sauer Antonio Rosas Miguel Cervantes 

机构地区：[1]Instituto de Ciencias Agrlcolas, Universidad Aut6noma de Baja California, Mexicali, Baja California 21100, Mexico [2]Facultad de Agronomla, Universidad Autonoma de Nuevo Leon, Monterrey, Mexico [3]IlAF, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Mich, Mexico

出　　处：《Journal of Agricultural Science and Technology(A)》2012年第5期619-627,共9页农业科学与技术（A）

摘　　要：Two experiments were conducted to evaluate the growth response and serum concentrations （SC） of amino acids （AA） in pigs fed wheat-based diets with either deficient, adequate or excess Lys and Thr. Previously, the standardized ileal digestibilities of AA in a basal diet were determined with five ileal cannulated pigs in a digestion trial. In experiment 1, 21 pigs （12.5±0.91 kg） were used to evaluate the effect of adding 0%, 0.69%, and 1.38% free L-Lys. The best growth response was obtained with 0.69% added L-Lys, equivalent to 1.05% total in the diet. The SC of Arg, Thr, and Val were lower （P 〈 0.05） in pigs fed the Lys adequate diet, compared to the deficient, but no further change occurred with excess Lys （P 〉 0.10）. Lys SC increased with each increment in the dietary Lys content （P 〈 0.05）. In experiment 2, 20 pigs （14.3 ± 1.57 kg） were used, and the addition of 0%, 0.14%, 0.28%, and 0.42% crystalline Thr, to the 0.69% L-Lys-supplemented basal diet, was evaluated. The best response was obtained with added 0.28% L-Thr, （0.66% total Thr）, but excess Thr reduced feed intake and growth rate. Moderate and excess levels of Yhr increased the SC of Thr, but excess reduced those of Va[ and Lys. These data show that excess Thr, but not Lys, affect the performance of growing pigs. Also, these data indicate that Val may become limiting in low protein diets with excess Lys or Thr.

关 键 词：PIGS LYSINE THREONINE low-wotein wheat. 

分 类 号：S816.48[农业科学—饲料科学] S828.5[农业科学—畜牧学]