Maurice D V, Hughes B L, Jones J E, Weber J M
Poult Sci. 1982 Dec;61(12):2421-9. doi: 10.3382/ps.0612421.
Four brown egg strains were used to study the effect of rearing diets on growth and performance. The treatments were arranged in a 4 x 3 factorial with two replicates of 45 birds. The control diet was formulated and fed to National Research Council recommendations. Birds on reverse protein (RP) were fed diets with 13, 16, and 19% protein and those on low protein (LP) regimen received a 13.5% protein diet with amino acids adjusted on a megacalorie basis to approximate the control diet. At 20 weeks of age pullets were caged and fed a standard layer diet. Logistic curves were fitted to the growth data by a nonlinear least squares method and the parameters of each curve analyzed. No significant strain x diet interactions were observed. There were significant differences among strains in weight gain and feed intake. Dietary regimens had no significant effect on total gain and feed intake. However, diets significantly altered age at one-half maximum growth or inflection point (alpha) and mean growth rate (rho). Inflection point of the growth curve was significantly delayed in birds fed RP and LP diets. Although apparent conversion was not affected by diets, the partition coefficients at any time (t) for maintenance (beta mt) and gain (beta gt) were altered. Neither strain nor dietary regimens affected abdominal fat or organ weights at the end of the rearing period. No significant effect of rearing dietary regimens was detected in age at 50% production or peak production, feed conversion, feed intake, livability, liver fat, abdominal fat, or shell strength. The reverse-protein regimen significantly depressed egg weight. The results of the study indicate that 1) the rearing dietary regimens were adequate for strains of different body weight and egg output characteristics; 2) dietary alteration of growth curve parameters failed to influence production, feed intake, mortality, shell strength, livability, liver fat, or abdominal fat during the production period.
使用四个褐壳蛋鸡品系来研究育雏日粮对生长和生产性能的影响。试验处理采用4×3析因设计，每个处理有两个重复，每个重复45只鸡。对照日粮按照美国国家研究委员会的建议进行配制和饲喂。采用反蛋白（RP）日粮的鸡饲喂蛋白质含量分别为13%、16%和19%的日粮，采用低蛋白（LP）日粮的鸡饲喂蛋白质含量为13.5%的日粮，并根据每兆卡能量调整氨基酸含量，使其近似于对照日粮。20周龄时，将小母鸡转入笼中，并饲喂标准蛋鸡日粮。通过非线性最小二乘法将逻辑曲线拟合到生长数据，并分析每条曲线的参数。未观察到显著的品系×日粮互作效应。品系间在体重增加和采食量方面存在显著差异。日粮处理对总增重和采食量没有显著影响。然而，日粮显著改变了达到最大生长一半时的年龄或拐点（α）以及平均生长速率（ρ）。饲喂RP和LP日粮的鸡生长曲线的拐点显著延迟。尽管表观转化率不受日粮影响，但维持（βmt）和增重（βgt）的任意时刻（t）的分配系数发生了改变。在育雏期结束时，品系和日粮处理均未影响腹脂或器官重量。在50%产蛋率或产蛋高峰期的年龄、饲料转化率、采食量、成活率、肝脏脂肪、腹脂或蛋壳强度方面，未检测到育雏日粮处理的显著影响。反蛋白日粮显著降低了蛋重。研究结果表明：1）育雏日粮处理对于不同体重和产蛋特性的品系是合适的；2）日粮对生长曲线参数的改变未能影响产蛋期的生产性能、采食量、死亡率、蛋壳强度、成活率、肝脏脂肪或腹脂。
