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,pHt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-1.0413(R2=0.9901)及y=-0.642 3 Ln(x)+2.56(R2=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 substitu-ting 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 repli-cates 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:1) drip loss of thigh muscle and serum cholesterol decreased significantly (P<0.001); pH1 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=2.9467 x-1.0413 (R2=0.9901)and y=- 0.642 3 Ln(x)+2.56(R2=0.993 6), respectively.This study has clearly demonstrated that de-creasing 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.
展开▼
