低粗蛋白质补充氨基酸饲粮对白羽半番鸭屠宰性能和胸肌成分的影响

Effects of Low Crude Protein Diets Supplemented With Amino Acids on Slaughter Performance and Composition of Breast Muscle of Mule Ducks

本试验旨在研究低粗蛋白质（ CP）补充氨基酸饲粮对白羽半番鸭屠宰性能和胸肌肌肉成分的影响。选取1日龄白羽半番鸭450只,随机分为3组,每组5个重复,每个重复30只鸭,公母各占1/2。对照组饲喂常规CP水平（1～21日龄19.0%,22～56日龄16.0%）的饲粮,试验组（试验Ⅰ组、试验Ⅱ组）分别饲喂在对照组饲粮基础上CP分别降低1、2个百分点并补充氨基酸的饲粮,试验期56 d。结果表明：1）各组56日龄的屠宰性能（屠宰率、全净膛率、腹脂率、腿比率、腿肌率、胸肌率、瘦肉率、皮脂率）均差异不显著（ P〉0.05）。2）与对照组相比,饲粮CP降低1、2个百分点时,白羽半番鸭胸肌中粗脂肪含量分别上升10.9%、28.3%（P〈0.05）,胸肌中CP含量分别下降1.1%、2.5%（ P〈0.05）,各组白羽半番鸭胸肌中大部分氨基酸含量差异不显著（ P〉0.05）,仅试验Ⅱ组母鸭胸肌中蛋氨酸、蛋氨酸＋半胱氨酸含量显著降低（P〈0.05）。由此可见,在氨基酸需要得到满足的条件下,饲粮CP降低1～2个百分点可提高白羽半番鸭胸肌中粗脂肪含量,降低胸肌中CP的含量,对其屠宰性能、胸肌大部分氨基酸含量及生长性能无显著影响。

This experiment was conducted to study the effect of low crude protein （ CP） diets supplemented with amino acids on slaughter performance and composition of breast muscle of Mule ducks. A total of 450 one-day-old Mule ducks were randomly assigned to 3 groups with 5 replicates and 30 ducks in each replicate （ 50% males, 50% females） . The control group received the diet included the normal level of CP （ 19% CP during 1 to 21 days of age, 16% CP during 22 to 56 days of age） , and the level of CP in diets of experimental group Ⅰ and experimental group Ⅱ were decreased by 1% and 2%, respectively, while supplied with com-pounded amino acids. The feeding trial lasted for 56 days. The results showed as follows：1） there was no sig-nificant effect on slaughter performance of ducks included slaughter rate, carcass yield rate, abdominal fat rate, leg rate, leg muscle rate, breast muscle rate, lean meat rate and subcutaneous fat rate at 56 days of age （ P〉0.05） . 2） Compared with the control group, the content of crude fat in breast muscle of ducks at 56 days of age was significantly increased by 10.9% and 28.3% associated with the descending of CP level in feed by 1%and 2% （ P〈0.05） , meanwhile, the content of CP in breast muscle of ducks at 56 days of age was decreased by 1.1% and 2.5%, respectively （ P〈0.05）;most of amino acid contents in breast muscle of ducks among all groups had no obvious difference （ P〉0.05） , but Met and Met＋Cys contents in breast muscle of female ducks in experimental group Ⅱ were significantly decreased （P〈0.05）. These results indicate that dietary CP de-creased by 1% to 2% have no obvious effects on growth performance, slaughter performance and most of ami-no acid contents in breast muscle of Mule ducks, but can significantly increase the crude fat content and de-crease CP content of breast muscle under the condition that amino acid in diet meet the need of birds.