本试验旨在研究1 d内动态营养对生长猪生长性能和血液生理生化指标的影响，并对其作用机理进行初步探讨。试验配制3种消化能水平相近、粗蛋白质水平不同的玉米-豆粕型饲粮：基础饲粮（粗蛋白质水平为21.04%）、高粗蛋白质水平饲粮（粗蛋白质水平为18.11%）和低粗蛋白质水平饲粮（粗蛋白质水平为15.29%）。选用体重相近的生长猪42头，阉公猪和母猪各21头，根据体重和性别随机分成3组：对照组、高-低粗蛋白质组和低-高粗蛋白质组。对照组每日均饲喂基础饲粮；高-低粗蛋白质组在早上饲喂高粗蛋白质水平饲粮、中午饲喂基础饲粮、晚上饲喂低粗蛋白质水平饲粮；低-高粗蛋白质组在早上饲喂低粗蛋白质水平饲粮、中午饲喂基础饲粮、晚上饲喂高粗蛋白质水平饲粮。试验期25 d。第25天每组随机选择6头试验猪采血，分离血清和血浆用于测定血清生化指标和血浆游离氨基酸含量。结果表明：与对照组相比，高-低粗蛋白质组平均日增重显著提高了9.97%（P<0.05），低-高粗蛋白质组有提高的趋势（P>0.05）；高-低粗蛋白质组和低-高粗蛋白质组血清谷氨酰转肽酶活性均显著降低（P<0.05），血清谷草转氨酶活性分别升高了35.1%和13.1%（P>0.05），谷丙转氨酶/谷草转氨酶分别降低了26.12%和24.63%（P>0.05）；高-低粗蛋白质组血浆缬氨酸、异亮氨酸和亮氨酸3种支链氨基酸（BCAA）含量均有降低的趋势（P>0.05），而低-高粗蛋白质组均有提高的趋势（P>0.05），与高-低粗蛋白质组相比，低-高粗蛋白质组3种血浆BCAA含量均显著升高（P<0.05）；高-低粗蛋白质组和低-高粗蛋白质组血浆丝氨酸含量均显著降低（P<0.05）。上述结果表明：在1 d内采食总量和总体营养水平相同的情况下，动态地饲喂不同粗蛋白质水平的方式可提高生长猪生长性能，影响血浆氨基酸含量等部分血液生理生化指标。

To study the effects of dynamic nutrition in one day on growth performance, blood physiology and biochemistry indexes of growing pigs, 42 pigs (half castrated boars and half sows) with similar body weight of (20.52±1.78) kg were randomly assigned into 3 groups according to body weight and sex. Three corn-soybean diets with similar digestive energy and different CP levels were formulated: basal diet (CP 21.04%), high CP level diet (CP 18.11%) and low CP level diet (CP 15.29%). The pigs in the control group were fed the basal diet in all day, those in the high-low CP group were fed high CP diet for breakfast, basal diet for lunch and low CP diet for supper, while those in the low-high CP group were fed low CP diet for breakfast, basal diet for lunch and high CP diet for supper. The experiment lasted for 25 days. Blood samples of 6 pigs selected from each group were obtained on day 25, and to examine the serum biochemical indices and plasma free amino acid contents. The results showed that compared with the control group, the average daily gain in the high-low CP group was significantly increased by 9.97% (P<0.05) and that in the low-high CP group had an increasing trend (P>0.05); in the high-low CP group and low-high CP group, serum glutamyltranspeptidase activity was significantly decreased (P<0.05), serum glutamic-oxal (o) acetic transaminase (AST) activity was increased by 35.1% and 13.1% (P>0.05), respectively, and alanine transarninase (ALT)/AST was decreased by 26.12% and 24.63% (P>0.05), respectively; the plasma contents of 3 kinds of branched chain amino acids (BCAA) including Val, Ile and Leu tended to decrease in the high-low CP group (P>0.05), while those in the low-high CP group tended to increase (P>0.05); compared with the high-low CP group, all the three kinds of plasma BCAA contents were significantly increased in the low-high CP group (P<0.05); and plasma Ser content was significantly decreased in both the two experimental groups (P<0.05). These findings suggest that dynamic nutrition affects the growth performance and blood biochemistry indexes, such as the amino acid contents of pigs under the condition of the same total feed intake and nutrition in one day.