二次回归正交旋转组合设计优化1～21日龄肉仔鸡胆碱和蛋氨酸需要量

本试验以低胆碱、低蛋氨酸饲粮为基础饲粮,通过两因子二次回归正交旋转组合设计,旨在研究1～21日龄肉仔鸡胆碱和蛋氨酸的最佳需要量.试验选用1日龄爱拔益加(AA)肉仔鸡480只,随机分为12个组,其中1～8组为试验组,9～12组为中心组,每组4个重复,每个重复10只鸡,公母各占1/2.分别以胆碱和蛋氨酸为自变量,以反映肉仔鸡生长性能和屠宰性能的各项指标为因变量拟合回归方程,估计1～21日龄肉仔鸡胆碱和蛋氨酸需要量.试验期21d.结果表明:一定水平的胆碱和蛋氨酸可显著改善1～21日龄肉仔鸡的平均日增重、料重比、屠宰率和腹脂率.从响应面图可以看出,当蛋氨酸水平为0.50％～0.70％时,随着胆碱水平的降低,肉仔鸡平均日增重逐渐降低;当蛋氨酸水平为0.42％～0.50％,胆碱水平为1300～1738 mg/kg时,肉仔鸡的料重比达到最低;蛋氨酸水平为0.50％～0.70％时,屠宰率随着蛋氨酸水平的升高而下降,蛋氨酸为0.36％～0.50％时,随着胆碱水平的升高,屠宰率呈上升趋势;随着胆碱水平的升高,腹脂率逐渐降低,当胆碱水平为1300 ～1920 mg/kg时,腹脂率随蛋氨酸水平的降低而下降.在本试验条件下,当胆碱水平为1434～1631mg/kg,蛋氨酸水平为0.47％时,肉仔鸡可达到最佳生长性能;当胆碱水平为1984 mg/kg,蛋氨酸水平为0.49％时,肉仔鸡可达到最佳屠宰性能.

Optimizing Requirements of Choline and Methionine Using Quadratic Regression Orthogonal Rotation Combination Design for Broilers Aged 1 to 21 Days

A research on choline and methionine requirements for broilers aged 1 to 21 days was carried out.A total of 480 one-day-old broilers were divided into 12 groups(4 replicates per group and each replicate had 10 broilers) in random.Groups 1-8 were experiment groups,and Groups 9-12 were center groups.A diet with low levels of choline and methionine was used as a basal diet in this experiment.To study the influence of different choline and methionine levels on growth performance and slaughter performance,a two-factor combinational design of quadratic regression orthogonal rotation was used.The experiment lasted for 21 d.The results showed that a certain level of choline and methionine could improve average daily gain(ADG),feed/gain(F/G),dressing percentage and abdominal fat percentage of broilers aged 1 to 21 days.The response surface graphs showed that when methionine levels were 0.50%-0.70%,the ADG was decreased with the reduction of choline levels.When methionine levels were 0.42%-0.50% and choline levels were 1 300-1 738 mg/kg,the F/G was minimum.When methionine levels were 0.50%-0.70%,the dressing percentage was decreased with the increasing of methionine levels;when methionine levels were 0.36%-0.50%,the dressing percentage was improved with the addition of choline.Abdominal fat percentage was decreased with the rise of choline levels;when choline levels were 1 300-1 920 mg/kg,abdominal fat percentage was decreased with the reducing of methionine levels.It can be concluded that the requirements of choline and methionine for optimal growth performance are 1 434-1 631 mg/kg and 0.47%,respectively.The requirements of choline and methionine for optimal slaughter performance are 1 984 mg/kg and 0.49%,respectively.