Takahashi K, Yodogawa S, Akiba Y, Tamura K
Department of Animal Science, Faculty of Agriculture, Tohoku University, Sendai-shi, Japan.
Br J Nutr. 1995 Aug;74(2):173-82. doi: 10.1079/bjn19950121.
The effect of dietary protein concentration on stress responses against injection of Escherichia coli lipopolysaccharide (LPS) was studied in male broiler chickens. Chickens (7 d of age) were fed on a 100 (low-protein; LP) or 300 g protein/kg (high-protein; HP) diet for 2 weeks. LPS was injected intraperitoneally every 2 d during the final 6 d, or once 16 h before the end of the experiment, at a concentration of 900 micrograms/chick. The LPS injection did not affect body-weight gain, feed intake, gain:intake ratio, or plasma Fe concentration. The single injection of LPS reduced plasma Zn concentration, but the repeated injections did not. Feeding the HP diet increased the response of plasma Zn concentration to the single injection of LPS. Plasma albumin concentration was reduced by LPS injection. Feeding the HP diet resulted in a higher plasma alpha 1-acid glycoprotein (AGP) concentration than feeding the LP diet, in chicks untreated with LPS. An increase in plasma AGP concentration observed after LPS injection in chicks fed on the LP diet was greater than that seen in chicks fed on the HP diet. No significant changes in plasma AGP concentration in response to repeated injections of LPS were observed in chicks fed on the HP diet. Plasma interleukin-1 (IL-1)-like activity was greater in chicks fed on the LP diet than in those fed on the HP diet, when LPS was injected. The response of plasma IL-1-like activity to the single injection of LPS in chicks fed on the LP diet was the greatest among the treatment groups. These results suggest that acute-phase responses to LPS injection are much greater in chicks fed on a LP diet than in those fed on a HP diet, and multiple injection of LPS weakens the responses.
研究了日粮蛋白质浓度对雄性肉鸡注射大肠杆菌脂多糖（LPS）应激反应的影响。将7日龄的鸡分别饲喂含100 g蛋白质/kg（低蛋白；LP）或300 g蛋白质/kg（高蛋白；HP）的日粮2周。在最后6天期间，每隔2天腹腔注射LPS，或在实验结束前16小时注射一次，浓度为900微克/只鸡。LPS注射不影响体重增加、采食量、增重：采食量比或血浆铁浓度。单次注射LPS可降低血浆锌浓度，但重复注射则无此作用。饲喂高蛋白日粮可增强血浆锌浓度对单次注射LPS的反应。LPS注射可降低血浆白蛋白浓度。在未用LPS处理的雏鸡中，饲喂高蛋白日粮的血浆α1-酸性糖蛋白（AGP）浓度高于饲喂低蛋白日粮的雏鸡。在饲喂低蛋白日粮的雏鸡中，LPS注射后观察到的血浆AGP浓度升高幅度大于饲喂高蛋白日粮的雏鸡。在饲喂高蛋白日粮的雏鸡中，未观察到重复注射LPS后血浆AGP浓度有显著变化。注射LPS时，饲喂低蛋白日粮的雏鸡血浆白细胞介素-1（IL-1）样活性高于饲喂高蛋白日粮的雏鸡。在各处理组中，饲喂低蛋白日粮的雏鸡血浆IL-1样活性对单次注射LPS的反应最大。这些结果表明，饲喂低蛋白日粮的雏鸡对LPS注射的急性期反应比饲喂高蛋白日粮的雏鸡大得多，多次注射LPS会减弱这些反应。
