THE EFFECTS OF CARCASS GRADE AND SEX ON THE LEAN CONTENT OF BEEF CARCASSES

Abstract
Heifer (n = 82) and steer (n = 89) carcasses were compared for lean content at the same grade (Canada A1 or A2), or at the same depth of average rib fat thickness within a grade (8.5 or 12.1 mm). Lean content for A1 grade carcasses was found to average 63.3% with a range from 55.6 to 69.2%. The corresponding figures for A2 grade carcasses were 60.0% lean and a range from 53.7 to 66.2%. A1 grade steer carcasses were found to contain 1.7% more lean than A1 grade heifer carcasses, but this difference was reduced to 1.2% when the comparison was made at an equal depth of subcutaneous fat thickness. There were no sex differences in lean content for A2 grade carcasses. The results are discussed with reference to lean content variation in existing carcass grades and pricing policies for heifer and steer carcasses of the same carcass grade. Key words: Beef, carcasses, steer, heifer, composition, grade