日粮ω6／ω3对爱拔益加肉仔鸡肉品质、血液脂质指标及脂肪酸组成的影响

Effect of Dietary ω6/ω3 on Meat Quality, Serum Lipids and Fatty Acid Profiles of Arbor Acres Broilers

本试验研究了日粮不同ω6/ω3多不饱和脂肪酸(PUFA)比值(ω6/ω3)对6周龄爱拔益加(AA)肉仔鸡肉品质、血液脂质指标及脂肪酸组成的影响。采用重量替代法使各处理日粮ω6/ω3比例分别为:30:1、20:1、10:1、5:1和2.5:1。选用体重接近的1日龄AA鸡母雏180只,随机分为5个处理,每个处理6个重复,每个重复6只鸡,试验期为6周,分1～4周和5～6周2个阶段。测定肉品质性状及腿肌脂肪酸组成。结果表明,随着日粮ω6/ω3的降低:(1)肌肉滴水损失极显著下降(P<0.001);当ω6/ω3为5:1时,pH_i最低,日粮ω6/ω3对肌肉肌内脂肪含量、肌苷酸含量没有显著影响(P>0.05);血液总胆固醇显著降低(P<0.001);(2)腿肌ω3 PUFA极显著增加(P<0.001),尤其是C18:3、C20:5和C22:5,ω6 PUFA显著下降(P<0.05),ω6/ω3从3.50降至1.60,多不饱和脂肪酸与饱和脂肪酸的比值在1.0左右(0.96～1.04);(3)极显著地增加了腿肌中C18:3向C20:5和C22:5的转化效率(P<0.001),长链ω3 PUFA(除了C18:3)在腿肌的含量高达7.24%。日粮ω6/ω3和腿肌中C20:5和C22:5的关系可分别用y=2.946 7 x^(-1.041 3)(R2=0.990 1)及y=-0.642 3 Ln(x)+2.56(R^2=0.993 6)表示。本试验证明降低日粮ω6/ω3,能在一定程度改善肉品质,并有效地增加腿肌中人体必需的ω3长链PUFA沉积,获得了营养丰富的鸡肉。

Effects of dietary ω6 to ω3 fatty acid ratio （ω6/ω3） on meat quality, serum lipid and fatty acid composition of thigh muscle were investigated in Arbor Acres （AA） broilers of 6 week. The chickens were fed diets containing linseed oil substituting for equivalent amount of corn oil to make the dietary ω6/ω3 of the 5 treatments to approximate 30 ： 1, 20 ： 1, 10 ： 1, 5 ： 1 and 2.5 ： 1. One hundred and eighty one-day-old broilers （female） were randomly allotted to 5 treatments with 6 replicates of 6 broilers per replicate. The experiment lasted for 6 weeks included two phases which were 1-4 and 5-6 week for testing the meat quality and fatty acid composition of thigh muscle. Results showed that as dietary ω6/ω3 decreasing：l） drip loss of thigh muscle and serum cholesterol decreased significantly （P〈0. 001）; pHi of thigh muscle was lower in birds fed 5 ： 1 ω6/ω3 diet than that in any other groups; there were no influences of diets on content of IMF and IMP in thigh muscle （P〈0.05） ; 2） the content of ω3 PUFA increased significantly （P〈0. 001）, especially the content of C18 ： 3, C20 ： 5 and C22 ： 5; ω6 PUFA （P〈0.05） and ω6/ω3 （from 3.50 to 1.60） decreased; the ratio of polyunsaturated to saturated fatty acids in thigh muscle in this experiment was about 1.0 （0.96-1.04） ; 3） the efficiency of conversion from C18 ： 3 to C20 ： 5 and C22 ： 5 increased significantly （P〈0. 001）; the highest content of ω3 PUFA （except C18 ： 3） in thigh muscle reached 7.24% ; the correlations between content of C20 ： 5 or C22 ： 5 in thigh muscle and dietary ω6/ω3 were y = 2. 946 7 x^- 1.0413 （R^2 = 0. 990 1）and y = - 0. 642 3 Ln（x） ＋ 2.56（R^2 = 0. 993 6）, respectively. This study has clearly demonstrated that decreasing the dietary ω6/ω3 could improve meat quality partly and increase the deposition of desirable ω3 long chain PUFA in the thigh muscle, thereby achieving nutritionally enriched meat.