Source: Beef Cattle Research Council
Project Title: Genetics of eating quality of high connective tissue beef
Researchers: Heather Bruce, Ph.D. hbruce@ualberta.ca Heather Bruce, Ph.D., Graham Plastow, Leluo Guan, Paul Stothard and Zhiquan Wang (University of Alberta), Manuel Juarez and Changxi Li (Agriculture and Agri-Food Canada)
Research in progress
Background
A number of commercially available DNA tests for beef tenderness effectively identify differences in ribeye tenderness that are related to post-mortem aging. Unfortunately, the beef cuts that need the most improvement are those that are tough due to connective tissue, which does not respond to aging. Additionally, there are theoretical concerns that selecting for feed efficiency may reduce beef tenderness.
Objectives
1) determine how breed type, selection for feed efficiency, and carcass grade affect the meat quality and connective tissue characteristics of muscles from the strip loin, inside round, cross-rib and top sirloin
2) relate the meat quality and connective tissue properties of the major muscles of these cuts to each other and to the phenotype and genotype of the steers from which the muscles were harvested.
What they will do
Major muscles of the strip loin, top sirloin, inside round and cross-rib will be collected from steers from the Livestock Gentec breeding herds. Fifty steers from the Kinsella control, Kinsella efficiency, purebred Angus and purebred Charolais herds will be randomly selected and slaughtered over two years at the Agriculture and Agri-Food Canada Lacombe abattoir. Full carcass information will be collected from each carcass. The strip loin, top sirloin butt, inside round and cross-rib will be removed from one or both sides depending upon muscle size. Tissue for DNA and functional genomics will be collected from each muscle. Each muscle will be assessed for intramuscular pH, fat, protein, moisture, colour, drip loss, cooking loss, Warner-Bratzler shear force, collagen content and collagen heat solubility, and consumer acceptability. DNA analyses will search for potential SNP markers that may explain differences in collagen characteristics and eating quality among muscles and populations, and the “control” and “efficiency” herds.
Implications
A better understanding of the genetic factors underlying differences in tenderness among different muscles of the beef carcass is an important first step in developing improved DNA marker panels for beef quality. Improved knowledge of the genetic interaction between feed efficiency and beef tenderness will be critical to effectively and appropriately implementing breeding tools for these traits.
