Gagaoua Mohammed, Monteils Valérie, Couvreur Sébastien, Picard Brigitte
UMR1213 Herbivores, INRA, VetAgro Sup, Clermont Université, Université de Lyon , 63122 Saint-Genès-Champanelle, France.
URSE, Université Bretagne Loire, Ecole Supérieure d'Agriculture (ESA) , 55 Rue Rabelais, BP 30748, 49007 Angers Cedex, France.
J Agric Food Chem. 2017 Sep 20;65(37):8264-8278. doi: 10.1021/acs.jafc.7b03239. Epub 2017 Sep 11.
Data from birth to slaughter of cull cows allowed using a PCA-based approach coupled with the iterative K-means algorithm the identification of three rearing practices classes. The classes were different in their carcass characteristics. Old cows raised mainly on pasture have better carcass characteristics, while having an equivalent tenderness, juiciness, flavor, intramuscular fat content, and pHu to those fattened with hay or haylage. The Longissimus thoracis muscle of the cows raised on pasture (with high physical activity) showed greater proportions of IIA fibers at the expense of the fast IIX ones. Accordingly, the meat of these animals have better color characteristics. Superoxide dismutase (SOD1) and αB-crystallin quantified by Dot-Blot were the only other biomarkers to be more abundant in "Grass" class compared to "Hay" and "Haylage" classes. The relationships between the biomarkers and the 6 carcass and 11 meat quality traits were investigated using multiple regression analyses per rearing practices. The associations were rearing practice class and phenotype trait-dependent. ICDH and TP53 were common for the three classes, but the direction of their entrance was different. In addition, rearing practices and carcass traits were not related with Hsp70-Grp75 and μ-calpain abundances. The other relationships were specific for two or one rearing practices class. The rearing practices dependency of the relationships was also found with meat quality traits. Certain proteins were for the first time related with some beef quality traits. MyHC-IIx, PGM1, Hsp40, ICDH, and Hsp70-Grp75 were common for the three rearing practices classes and retained to explain at list one beef quality trait. A positive relationship was found between PGM1 and hue angle irrespective of rearing practices class. This study confirms once again that production-related traits in livestock are the result of sophisticated biological processes finely orchestrated during the life of the animal and soon after slaughter.
从淘汰母牛出生到屠宰的数据，采用基于主成分分析（PCA）的方法结合迭代K均值算法，识别出三种饲养方式类别。这些类别在胴体特征方面存在差异。主要在牧场饲养的老龄母牛具有更好的胴体特征，同时在嫩度、多汁性、风味、肌内脂肪含量和最终pH值方面与用干草或青贮饲料育肥的母牛相当。在牧场饲养（运动量较大）的母牛的胸最长肌中，IIA型纤维比例更高，快速收缩的IIX型纤维比例相应减少。因此，这些动物的肉具有更好的色泽特征。通过斑点印迹法定量的超氧化物歧化酶（SOD1）和αB晶状体蛋白是“草饲”类别中比“干草饲”和“青贮饲料饲”类别更丰富的仅有的其他生物标志物。针对每种饲养方式，使用多元回归分析研究了生物标志物与6个胴体性状和11个肉质性状之间的关系。这些关联取决于饲养方式类别和表型性状。异柠檬酸脱氢酶（ICDH）和TP53在三个类别中都有，但它们进入的方向不同。此外，饲养方式和胴体性状与热休克蛋白70-葡萄糖调节蛋白75（Hsp70-Grp75）和μ-钙蛋白酶丰度无关。其他关系则特定于两种或一种饲养方式类别。在肉质性状方面也发现了关系对饲养方式的依赖性。某些蛋白质首次与一些牛肉品质性状相关。肌球蛋白重链-IIx（MyHC-IIx）、磷酸葡萄糖变位酶1（PGM1）、热休克蛋白40（Hsp40）、异柠檬酸脱氢酶（ICDH）和热休克蛋白70-葡萄糖调节蛋白75（Hsp70-Grp75）在三种饲养方式类别中都有，并且被保留下来以解释至少一种牛肉品质性状。无论饲养方式类别如何，都发现PGM1与色泽角呈正相关。这项研究再次证实，家畜的生产相关性状是动物生命期间及屠宰后不久精心编排的复杂生物学过程的结果。
