Hansen B C, Lewis A J
Department of Animal Science, University of Nebraska, Lincoln 68583-0908.
J Anim Sci. 1993 Aug;71(8):2110-21. doi: 10.2527/1993.7182110x.
The effects of dietary CP level (actually corn:soybean meal ratio) and BW on N intake, N digestibility, the efficiency of utilization of N (apparent biological value), and N retention were measured in 36 pigs: 12 boars (five collection periods), 12 barrows (four collection periods), and 12 gilts (nine collection periods). Initial and final BW of the boars, barrows, and gilts were 19, 24, and 27 kg and 80, 69, and 110 kg, respectively. Diets were based on corn and soybean meal and contained 11 to 23% CP. Averaged over all collection periods, N retention was 24.2, 20.0, and 19.8 g/d for boars, barrows, and gilts, respectively. The response of N retention to CP levels was quadratic (P < .15) and cubic (P < .01) for boars, linear (P < .01) and quadratic (P < .05) for barrows, and linear (P < .15) for gilts. Rates of N retention responded quadratically (P < .001) for all sexes as pigs gained weight, reaching a maximum when pigs weighed 55 to 65 kg. Multiple-regression analyses were conducted and equations were developed that described the effects of CP level (or lysine intake) and BW on N retention for each sex. The results indicated that N balance was a function of both CP level (or lysine intake) and BW and that the nature of the response differed for each sex.
在36头猪身上测定了日粮粗蛋白水平（实际为玉米：豆粕比例）和体重对氮摄入量、氮消化率、氮利用率（表观生物学价值）和氮保留的影响，其中包括12头公猪（5个采集期）、12头阉公猪（4个采集期）和12头后备母猪（9个采集期）。公猪、阉公猪和后备母猪的初始体重和终末体重分别为19、24和27千克以及80、69和110千克。日粮以玉米和豆粕为基础，粗蛋白含量为11%至23%。在所有采集期内平均计算，公猪、阉公猪和后备母猪的氮保留量分别为24.2、20.0和19.8克/天。公猪的氮保留量对粗蛋白水平的反应呈二次曲线（P < 0.15）和三次曲线（P < 0.01），阉公猪呈线性（P < 0.01）和二次曲线（P < 0.05），后备母猪呈线性（P < 0.15）。随着猪体重增加，所有性别的氮保留率均呈二次曲线反应（P < 0.001），在猪体重达到55至65千克时达到最大值。进行了多元回归分析并建立了方程，描述了粗蛋白水平（或赖氨酸摄入量）和体重对各性别氮保留的影响。结果表明，氮平衡是粗蛋白水平（或赖氨酸摄入量）和体重的函数，且各性别的反应性质不同。
