Department of Applied Biology, University of Perugia, Borgo 20 Giugno, 74, 06121 Perugia, Italy.
Poult Sci. 2012 Aug;91(8):2039-45. doi: 10.3382/ps.2012-02228.
According to EC regulation 889/08, different European countries should draw up a list of slow-growing strains adapted to an organic system, and in the meantime, provide this information to operators and the European Union commission. Thus, the aim of the present work was to evaluate the effect of poultry genotype on fatty acid composition and lipid indices of poultry meat. Six poultry genotypes (100 birds each), each with a different growth rate (slow-growing: Leghorn, Ancona, Cornish×Leghorn; medium-growing: Kabir, Naked neck; fast-growing: Ross), were reared under an organic system. Breast meat fatness, fatty acid composition, and indices were largely related to genotype, as slow-growing strains had higher elongase, thioesterase, and Δ5/Δ6 desaturase indices accompanied by a lower Δ9. Differences in the fatty acid profiles were observed by varying contents of total saturated fatty acids, with a higher value seen in Leghorn chickens and a lower value seen in commercial lines. On the contrary, Leghorn and Ancona chickens exhibited higher amounts of stearic acid and total polyunsaturated fatty acids compared with commercial genotypes, both in the total content and in the different fractions (total n-3 and total n-6). Despite the increased consumption of fresh forage, the lower linolenic acid in meat of the slow-growing strain could be explained by the higher conversion of this fatty acid to its long-chain derivatives.
根据欧盟法规 889/08，不同的欧洲国家应制定一份适应有机系统的生长缓慢菌株清单，并同时向经营者和欧盟委员会提供此信息。因此，本研究的目的是评估家禽基因型对禽肉脂肪酸组成和脂质指数的影响。在有机系统下饲养了 6 种家禽基因型（每种 100 只），每种基因型的生长速度不同（生长缓慢的：莱航鸡、安科纳鸡、科尼什鸡×莱航鸡；中速生长的：卡比尔鸡、裸颈鸡；快速生长的：罗斯鸡）。胸肉脂肪含量、脂肪酸组成和指数与基因型密切相关，因为生长缓慢的品种具有更高的伸长酶、硫酯酶和 Δ5/Δ6 去饱和酶指数，同时 Δ9 较低。通过改变总饱和脂肪酸的含量观察到脂肪酸谱的差异，莱航鸡的含量较高，商业品种的含量较低。相反，与商业品种相比，莱航鸡和安科纳鸡的硬脂酸和总多不饱和脂肪酸含量较高，无论是总含量还是不同分数（总 n-3 和总 n-6）。尽管新鲜饲料的消耗量增加，但生长缓慢的禽肉中 n-3 亚麻酸含量较低，可能是由于这种脂肪酸向其长链衍生物的转化率较高所致。
