Using genomics and proteomics to assess the pre-slaughter stress effect on the meat quality of crossbred cattle finished in feedlot

Abstract

This approach has the aim of evaluate molecular markers associated with meat quality and physiologic response to stress pre-slaughter of a commercial bovine herd finished in feedlot. Thus, meat and blood samples from F1 animals derived from South African Simmental (males) and Nellore (females) crossbreed will be analyzed. Blood samples will be collected for endocrine analysis (cortisol and glucose) and genomic analysis, moreover samples from the Longissimus dorsi (LD) muscle will be collected for meat quality and proteomics analysis, as well as, quantification of Heat Shock Proteins (HSP). The LD samples will be carried out in 0 and 14 days of maturation, where color determination, water cooking loss, shear force (tenderness) and % of meat lipid, will be performed. The characterization and determination of polymorphics genotypes (SNP) for markers of m-calpain gene (CAPN 4751 e 4756), of UOGCAST1 marker, associated to calpastatin, TG5 marker, associated to marbling and HSPB1 e HSP 70 markers associated to Heat Shoeck Proteins (27 e 70), will be analyzed using Real time PCR. Glucose, cortisol and Heat Shock Protein (27 e 70) measurements will be performed using immunoenzymatic kits. The proteomic analysis will be performed by two dimensional electrophoresis with the subsequent identification of peptides by mass spectrometry. (AU)