Independent testing of the e+* camera to determine whether it could accurately and repeatedly estimate marbling score and lean yield in concordance with graders’ scores was conducted by Wayne Robertson, a meat quality biologist at AAFC’s Lacombe Research Centre.
The Canada Agriculture Products Act provides the authority to grade and the Livestock and Poultry Carcass Grading Regulations allow the minister of agriculture to designate the use of equipment in grading provided it meets specifications set out in the testing protocol, Rober tson explains.
The original protocol for camera grading equipment was designed specifically to test the methodology of the CVS camera. The procedures were updated in July of 2009, to be more generally applicable and to recognize testing completed in the U. S. and USDA approvals for some grading attributes measured by the e+* instrument.
The testing procedure stipulates that 200 carcasses must be evaluated in two ways: Three images of the rib-eye area between the 12th and 13th ribs on the left side of each carcass must be taken using the triple-placement method, whereby the camera is removed and replaced for each image; and obtaining images from both sides of the same group of carcasses passed by the camera a second time at typical grade chain speeds.
Because Canada harmonized its marbling standards with the U. S. in 1999, the Canadian Cattlemen’s Association and the Canadian Meat Council requested that the minister accept the USDA marbling research that arrived at the break points for each marbling level to be programmed into the equipment. However, Canada’s lean yield equation and three yield classes are different from those in the U. S., where the heart, kidney, pelvic fat and carcass weight are considered in the yield equation and there are five yield classes.
Robertson’s task focused on whether the e+* instrument could be calibrated to provide Canada yield class measurements that concurred with the yield grade determined by three CBGA graders. He also evaluated the accuracy and repeatability of rib-eye dimension and grade fat thickness measurements. The camera rib-eye measurements were checked against acetate tracings of the left rib-eye taken for testing purposes, but not used in practice when grading at the plants. Robertson also looked at how well the camera marbling class correlated with that of the graders.
The evaluations were carried out at XL Beef at Brooks and Cargill Food Solutions at High River.
“The critical attribute required to be estimated is carcass lean per cent, which the instrument does with a high level of accuracy relative to the averaged lean per cent estimated by three official graders using the Canada grade ruler,” says Robertson.
He recommends approval of the e+* Technology GmbH instrument technology for estimation of marbling score using the USDA-approved algorithms and break points. He also contends that the instrument should be approved for estimation of lean yield percentage and Canada yield grade using the average fat thickness in the cyan region of the image to determine grade fat and laser-corrected rib-eye length measurements to determine the muscle score.