X-Ray computed tomography evaluation of intramuscular fat content in Hungarian simmental cattle

Abstract

Intramuscular fat content (marbling) is an economically important factor in many beef carcass classification systems. The aim of this study was to evaluate marbling of longissimus muscle with different methods (USDA marbling score, image analysis of X-ray computed tomography scans, and conventional method), moreover it was aimed to establish the relationship between marbling traits and SEUROP conformation and fat score. Bulls (n=46) were slaughtered at an average weight of 536±126 kg and an average age of 646±437 days. The average growth rate of bulls was 955 g day–1, the average chemical fat content of longissimus varied between 2.3 to 5.0% in fat classes. The intramuscular fat content on CT-scans closely correlated with chemical fat content (r=0.9). The highest frequency of USDA marbling score was “small” (55.2%), followed by “slight” (25.5%), “modest” (17%), and “moderate” (2.1%). Bulls with higher growth rate had lower CT-measured marbling traits in longissimus muscle (r = –0.4 – –0.5). The CT scans of longissimus muscle can be used for the evaluation of marbling in Hungarian Simmental cattle. The SEUROP conformation and fat score have no relationship with marbling traits.