Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, Jalisco, Mexico.
J Anim Sci. 2013 Jan;91(1):477-82. doi: 10.2527/jas.2012-5495. Epub 2012 Oct 9.
Twenty-three thousand four hundred eighty-four beef carcasses were classified according to the Mexican norm NMX-FF-078-SCFI-2002 at the No. 51 Federal Inspected Type abattoir located in the State of Tabasco, Mexico, owned by the Beef Cattle Union of Tabasco State. Tabasco State has a Tropical humid (Am) and subhumid (Aw) climate with rains in summer. The study took place between November 2009 and February 2010. The objective of this study was to evaluate independently the influence of each of the grading criteria used for classification on the final quality grade and determine areas for improvement to enhance the quality of Mexican beef carcasses. The beef carcass norm implementation followed a mechanistic approach of the 5 basic evaluation criteria applied in the sequential order: 1) maturity (age), 2) conformation (muscularity), 3) color of the meat, 4) fat color, and 5) distribution of the subcutaneous fat. The quality grades possible were Supreme, Select, Standard, Commercial, Out of Grade, and Veal. The proportion of carcasses classified as Select, Standard, Commercial, Out of Grade, and Veal were 13.4, 45.8, 27.4, 10.6, and 2.7%, respectively. No carcasses had a final quality grade of Supreme. Based on maturity, 79.2% of the carcasses met the specifications for Supreme; however, when the next criterion, conformation, was evaluated only 0.5% of the carcasses met the specifications for Supreme. When carcasses with a criterion grade of Supreme are not included in the analysis, the γ and κ statistics indicated that maturity and conformation have the greatest association and agreement, respectively, with final quality grade. When carcasses with a criterion grade of Supreme are included in the analysis, the κ statistic for the assessment of agreement between final quality grade and criterion indicated a descending order of conformation, subcutaneous fat distribution, maturity, meat color, and fat color. Thus, based on the degree of association and agreement, conformation was identified as the criterion with the greatest influence on final quality grade and the primary reason for the absence of Supreme grading among the carcasses studied. It is concluded that the application of the Mexican beef carcass classification norm NMX-FF-078-SCFI-2002 into a sample population of beef cattle coming out of a tropical beef production environment highlights a system capable of sending animals to slaughter at an early age with adequate meat and fat color and subcutaneous fat distribution although requiring improvement in conformation.
在位于墨西哥塔巴斯科州的第 51 号联邦检查型屠宰场，对来自塔巴斯科州养牛工会的 23484 头牛肉胴体进行了分类，该屠宰场符合墨西哥标准 NMX-FF-078-SCFI-2002。塔巴斯科州属于热带湿润（Am）和亚湿润（Aw）气候，夏季降雨较多。该研究于 2009 年 11 月至 2010 年 2 月进行。本研究的目的是独立评估用于分类的每个分级标准对最终质量等级的影响，并确定需要改进的领域，以提高墨西哥牛肉胴体的质量。牛肉胴体标准的实施遵循了 5 个基本评估标准的机械方法，按顺序应用：1）成熟度（年龄），2）结构（肌肉发达程度），3）肉色，4）脂肪色，和 5）皮下脂肪分布。可能的质量等级有特级、精选级、标准级、商业级、淘汰级和小牛肉级。分类为精选级、标准级、商业级、淘汰级和小牛肉级的胴体比例分别为 13.4%、45.8%、27.4%、10.6%和 2.7%。没有胴体的最终质量等级为特级。基于成熟度，79.2%的胴体符合特级规格；然而，当评估下一个标准——结构时，只有 0.5%的胴体符合特级规格。当不包括特级标准等级的胴体进行分析时，γ和κ统计数据表明成熟度和结构与最终质量等级具有最大的关联性和一致性。当包括特级标准等级的胴体进行分析时，评估最终质量等级和标准之间一致性的κ统计数据表明，结构、皮下脂肪分布、成熟度、肉色和脂肪色的顺序依次降低。因此，基于关联度和一致性，结构被确定为对最终质量等级影响最大的标准，也是研究胴体中没有特级等级的主要原因。结论是，在热带牛肉生产环境中，应用墨西哥牛肉胴体分类标准 NMX-FF-078-SCFI-2002 对牛肉种群样本进行分类，突出了一个能够在动物早期进行屠宰的系统，其具有足够的肉色和脂肪色以及皮下脂肪分布，但需要改善结构。
