饲粮双低菜粕水平对黄羽肉鸡生长性能、血液指标及肉品质的影响

Effect of Dietary Double-Low Rapeseed Meal Level on Production Performance,Blood Indexes and Meat Quality of Yellow-Feathered Broilers

本试验旨在研究饲粮双低菜粕水平对1～63日龄黄羽肉鸡生产性能、血液生化及肉品质的影响。试验选用1日龄快长型黄羽肉公鸡1200只，随机分为5组，每组6个重复，每个重复40只鸡。处理I—V小鸡阶段双低菜粕添加水平为0％、2．5％、5％、7．5％、10％；中鸡阶段为0％、3％、6％、9％、12％；大鸡阶段为0％、7％、10．5％、14％、17．5％，试验期为63d。结果表明：与对照组相比，双低菜粕添加量为10％时可显著降低1～21日龄试鸡日增重，并提高饲料增重比（P〈0．05），各阶段双低菜粕添加量为5％、6％和10．5％时可显著降低63日龄试鸡体重（P〈0．05），当添加量达到10％、12％和17．5％时可显著提高1—63日龄试鸡饲料增重比（P〈0．05）；各阶段饲粮双低菜粕添加量达到10％、12％和17．5％时显著降低了63日龄试鸡血浆游离T3和游离T4含量（P〈0．05），但各组间63日龄试鸡血浆谷草转氨酶、肌酸激酶、乳酸脱氢酶活性和肝脏谷胱甘肽硫转移酶活性均未见明显变化（P〉0．05），肝脏切片分析未见明显病变；各阶段添加10％、12％和17．5％的双低菜粕可显著降低63日龄试鸡屠宰后45min的胸肉L＊值，并提高a＊值（P〈0．05），但对63日龄试鸡胸肉的感官风味及屠宰后96h的pH、L＊、a；＊、b＊则无显著影响（P〉0．05）。试验结果提示，在快长型黄羽肉鸡饲粮小鸡阶段、中鸡阶段和大鸡阶段分别添加2．5％、3％和7％的双低菜粕（硫代葡萄糖甙含量为7．01μmol／g）未影响黄羽肉鸡的生长、甲状腺激素水平、机体抗氧化功能及肉品质。

The experiment was designed to study the effects of dietary double - low rapeseed meal on production performance, blood biochemistry and meat quality in yellow - feathered broilers aged from 1 to 63 days. The experience selected 1,200 fast - growth yellow - feathered cock at the age of 1 days which were randomly assigned to 5 groups, each consisiting of 6 replicates of 40 cocks. The basal diet （ Ⅰ ） was a typical corn - soybean ration while the experimental diets （ Ⅱ to Ⅴ） substituted DL - RSM for soybean meal. The level of substitution in starter （ 1 - 21 d）, grower （22 -42 d） and finisher（43 -63 d） diets was： 11 2.5%, 3% then 7% ; m, 5%, 6% then 10.5% ;Ⅳ, 7.5%, 9% then 14% ; Ⅴ, 10%, 12% then 17.5%. A sample of birds from each replicate was blood sampled and killed at the end （63 d） for carcass and biochemical analysis. Compared to the control diet （ Ⅰ ）, diet V decreased average daily gain （ADG） and increased feed to gain ratio （F：G） between 1 to 21 d（P 〈 0.05 ） ; diets Ⅲ to Ⅴ decreased body weight （BW） at 63 d （ P 〈 0.05 ）, and diet V increased F ： G （ P 〈 0.05 ）. Diet Ⅴ decreased fT3 and iT4 content in plasma at 63 d （ P 〈 0.05 ）. There was no differences from diet in plasma activities of glutamic - oxaloacetic transaminase, creatine kinase, lactate dehydrogenase or hepatic glutathione S - transferases activity （ P 〉 0.05）. Pathological changes in liver were not obviously detected. Increased double -low rapeseed meal content of the diet caused favorable changes in selected functional properties of the meat, including decrease in L ＊ value and increase in a ＊ value in broilers fed diets V （ P 〈 0.05 ）. There was no differences in breast meat sensory flavor, pH, L 3.0% growth ＊ , a＊ and b＊ values 96 h after slaugh then 7.0% double - low rapeseed meal） performance, thyroid hormone secretion, ter among treatments （P 〉 0.05 ）. In conclusion, Diet Ⅱ （2.5 %, in Lingnan yellow -feathered broiler diets had no negative effects on antioxidant capacity and meat quality.