|Validation in the different animal groups of the five sets of probes belonging to the heat shock protein family to predict variability in tenderness|
|Initial tenderness||Overall tenderness|
|Animal group||Number of animals||R2||P value||R2||P value|
|Young bulls slaughtered year 1||25||HSP gene expression levels||0.39||0.07||0.44||0.04|
|Steers slaughtered year 1||21||HSP gene expression levels||0.45||0.08||0.49||0.05|
|Young bulls slaughtered year 2||30||HSP gene expression levels||0.37||0.04||0.40||0.03|
|Steers slaughtered year 2||19||HSP gene expression levels||0.20||0.68||0.23||0.58|
Multiple regression analyses were performed with the combination of the 5 groups of probes (DNAJA1HspH1, HspA8, plus two groups of probes for HspB1-Hsp27) to predict beef initial or overall tenderness for young bulls or steers slaughtered year 1 or year 2. Multiple regression analyses were also performed with the combination of four muscle biochemical traits (Intramuscular fat content, mean fiber area, total collagen content and collagen solubility) previously shown  to be associated with beef quality. The proportion of the variability in tenderness which is explained by the combination of the 5 groups of probes is indicated (R2) as well as the associated P value.
Hocquette et al.
Hocquette et al. BMC Veterinary Research 2012 8:135 doi:10.1186/1746-6148-8-135