From protein markers to phenotyping tools for evaluation of beef tenderness

High and uncontrolled beef tenderness variability is at the origin of a dissatisfaction of the beef consumers. Today tenderness can be estimated only after slaughter, by sensory analysis tests and/or mechanical measurements. For beef producers, it is of interest for breeding or finishing purposes to predict the ability of live animals to produce good meat, with specific attention towards tenderness. Thus, the Beef sector is looking for biological or molecular indicators that would identify live animals with desirable quality attributes, in order to direct them towards the most appropriate production system. Tenderness is a complex trait under multifactorial determinant leading to a difficult control. For several years, various genomics programs have been conducted at the national and international level in order to reveal genomic markers of tenderness (Cassar-Malek et al., 2008). Comparative transcriptomic and proteomic analysis, conducted on bovine muscles with low or high tenderness scores estimated by sensory analysis and/or mechanical measurements, bring up a list of potential biological markers which may be used as phenotypic markers to predict the ‘tenderness potential’ of an animal or a carcass. This phenotypic analysis could be done either at the mRNA or protein level. In this abstract, we will focus on the protein level. The strategy developed by our team over a few years is: 1) to validate the relationship between meat tenderness and the protein markers on a large number of cattle types as the most representative of the French production systems and beef consumption (male and female, beef and dairy breeds); 2) to determine the effects of management factors (age and diet) on the expression of these markers; 3) to develop an antibody micro-array prototype for molecular phenotyping of beef tenderness from the list of validated markers. This antibody micro-array will be available for the Beef industry for evaluation of meat quality and for optimization of cattle breeding for meat production. This tool could also be used for tenderness phenotyping in genomic breeding schemes.