Carcass Traits Determining Quality and Yield Grades of Hanwoo Steers

S S Moon,S K Jin,G B Park,I H Hwang,J G Lee,S T Joo

doi:10.5713/ajas.2003.1049

Abstract

A group of Hanwoo (Korean cattle) steers (n=14,386) was sampled from a commercial abattoir located in Seoul over one year period (spring, summer, autumn and winter) and their carcass traits were collected. Carcass traits assessed by an official meat grader comprised degree of marbling, meat color, fat color, texture and maturity for quality grade, and back fat thickness, ribeye area and carcass weight for yield grade. A heavier carcass with a higher marbling score, more red meat color and white fat color received better quality grade (p<0.05). Regression analysis showed that the marbling score was the strongest attribute (partial R 2 =0.88) for quality grade. Lighter carcasses with a thinner back fat and larger ribeye area received higher yield grade score. The back fat thickness was the most negative determinant of yield grade (Partial R 2 =-0.66). The slaughter season had a little effect on quality and yield grades. As slaughter weight increased, back fat thickness and ribeye area increased linearly, whereas marbling score reached its asymptotic level at approximately 570 kg. As a consequence, quality grade showed a considerable improvement up to 570 kg, but increases in slaughter weight afterward showed a little benefit on quality grade. There was a clear curvilinear relationship between slaughter weight and yield grade in that the yield grade reached its highest point at approximately 490 kg and decreased afterward. These results suggested that 570 kg at the age of 24 months might be the economic slaughter weight for quality grade but 490 kg for yield grade.

Highlights

Marbling is a prime theme in Korean beef industry, as consumers judge meat quality on the basis of the degree of marbling, and they are willing to pay premium for highly marbled product (APGS report, 2001)
Quality grade was primarily determined by marbling score and adjusted by other carcass traits such as meat color, fat color, texture and maturity when there was a particular defect in these traits
Yield grade was determined on the basis of estimated retail cut percentage, which was a function of back fat thickness, ribeye area and cold carcass weight

Summary

Introduction

Marbling is a prime theme in Korean beef industry, as consumers judge meat quality on the basis of the degree of marbling, and they are willing to pay premium for highly marbled product (APGS report, 2001). Quality grade was primarily determined by marbling score and adjusted by other carcass traits such as meat color, fat color, texture and maturity when there was a particular defect in these traits. Yield grade was determined on the basis of estimated retail cut percentage, which was a function of back fat thickness, ribeye area and cold carcass weight.

Results

Conclusion