1Department of Agricultural and Food Sciences (DISTAL),University of Bologna,Viale Fanin 46,40127 Bologna,Italy.
2Research Centre for Animal Production and Aquaculture (CREA),via Salaria 31, 00015 Monterotondo,Italy.
Animal. 2019 May;13(5):924-932. doi: 10.1017/S1751731118002082. Epub 2018 Aug 28.
Subcutaneous fat thickness and fatty acid composition (FAC) play an important role on seasoning loss and organoleptic characteristics of seasoned hams. Dry-cured ham industry prefers meats with low contents of polyunsaturated fatty acids (PUFA) because these negatively affect fat firmness and ham quality, whereas consumers require higher contents in those fatty acids (FA) for their positive effect on human health. A population of 950 Italian Large White pigs from the Italian National Sib Test Selection Programme was investigated with the aim to estimate heritabilities, genetic and phenotypic correlations of backfat FAC, Semimembranosus muscle intramuscular fat (IMF) content and other carcass traits. The pigs were reared in controlled environmental condition at the same central testing station and were slaughtered at reaching 150 kg live weight. Backfat samples were collected to analyze FAC by gas chromatography. Carcass traits showed heritability levels from 0.087 for estimated carcass lean percentage to 0.361 for hot carcass weight. Heritability values of FA classes were low-to-moderate, all in the range 0.245 for n-3 PUFA to 0.264 for monounsaturated FA (MUFA). Polyunsaturated fatty acids showed a significant genetic correlation with loin thickness (0.128), backfat thickness (-0.124 for backfat measured by Fat-O-Meat'er and -0.175 for backfat measured by calibre) and IMF (-0.102). Obviously, C18:2(n-6) shows similar genetic correlations with the same traits (0.211 with loin thickness, -0.206 with backfat measured by Fat-O-Meat'er, -0.291 with backfat measured by calibre and -0.171 with IMF). Monounsaturated FA, except with the backfat measured by calibre (0.068; P<0.01), do not show genetic correlations with carcass characteristics, whereas a negative genetic correlation was found between MUFA and saturated FA (SFA; -0.339; P<0.001). These results suggest that MUFA/SFA ratio could be increased without interfering with carcass traits. The level of genetic correlations between FA and carcass traits should be taken into account in dealing with the development of selection schemes addressed to modify carcass composition and/or backfat FAC.
皮下脂肪厚度和脂肪酸组成（FAC）在调味损失和调味火腿的感官特性方面起着重要作用。干腌火腿行业更喜欢不饱和脂肪酸（PUFA）含量低的肉，因为这些脂肪酸会对脂肪硬度和火腿质量产生负面影响，而消费者则需要这些脂肪酸（FA）含量更高，因为它们对人体健康有积极影响。对来自意大利国家 sib 测试选择计划的 950 头意大利大白猪种群进行了研究，目的是估计背脂 FAC、半膜肌肌内脂肪（IMF）含量和其他胴体性状的遗传力、遗传和表型相关性。这些猪在同一中央测试站的受控环境条件下饲养，并在达到 150 公斤活重时进行屠宰。采集背脂样本，通过气相色谱法分析 FAC。胴体性状的遗传力水平从估计胴体瘦肉百分比的 0.087 到热胴体重的 0.361。FA 类的遗传力值较低至中等，均在 0.245（n-3 PUFA）至 0.264（单不饱和 FA（MUFA））之间。多不饱和脂肪酸与腰厚（0.128）、背脂厚度（Fat-O-Meat'er 测量的背脂为-0.124，卡尺测量的背脂为-0.175）和 IMF（-0.102）呈显著遗传相关性。显然，C18:2(n-6) 与相同性状（与腰厚的 0.211、与 Fat-O-Meat'er 测量的背脂的 0.206、与卡尺测量的背脂的 0.291 和与 IMF 的 0.171）具有相似的遗传相关性。MUFA 除与卡尺测量的背脂（0.068；P<0.01）外，与胴体特性无遗传相关性，而 MUFA 与饱和 FA（SFA）呈负遗传相关性（-0.339；P<0.001）。这些结果表明，MUFA/SFA 比值可以增加，而不会干扰胴体性状。在制定旨在改变胴体组成和/或背脂 FAC 的选择计划时，应考虑 FA 与胴体性状之间的遗传相关性水平。
