Yuan J H, Austic R E
Department of Animal Science, Cornell University, Ithaca, New York 14853, USA.
Poult Sci. 2001 Sep;80(9):1353-6. doi: 10.1093/ps/80.9.1353.
An experiment was carried out to determine the effect of dietary protein level on the specific activity of hepatic L-threonine dehydrogenase in young growing chicks. Six replicate pens of seven Leghorn chicks were fed semipurified diets containing 23, 27, or 32% CP with identical relative proportions of amino acids in each protein group. Body weights and feed consumption were measured for 3 d, and hepatic mitochondria were isolated for assay of threonine dehydrogenase (TDH) activity. Weight gains and feed efficiency increased at each level of protein supplementation, but feed consumption was not affected by protein level. The specific activity of threonine dehydrogenase in isolated liver mitochondria was significantly (P < 0.05) higher in the 32% CP group than in the 23% CP group, and the activity in the 27% CP group was intermediate. We conclude that moderate increases in dietary protein level result in elevated hepatic threonine dehydrogenase activity in growing chicks.
进行了一项实验，以确定日粮蛋白质水平对幼龄生长鸡肝脏L-苏氨酸脱氢酶比活性的影响。将7只来航鸡雏鸡分为6个重复栏，分别饲喂含23%、27%或32%粗蛋白的半纯化日粮，每个蛋白质组的氨基酸相对比例相同。测量3天的体重和采食量，并分离肝脏线粒体以测定苏氨酸脱氢酶（TDH）活性。在每个蛋白质补充水平下，体重增加和饲料效率均有所提高，但采食量不受蛋白质水平的影响。在分离的肝脏线粒体中，32%粗蛋白组的苏氨酸脱氢酶比活性显著（P<0.05）高于23%粗蛋白组，27%粗蛋白组的活性介于两者之间。我们得出结论，日粮蛋白质水平适度增加会导致生长鸡肝脏苏氨酸脱氢酶活性升高。
