Estimation of the basic quality grade of beef carcasses according to bone maturity, marbling, and Bos indicus phenotypic predominance

Abstract

In order to estimate the Basic Quality Grade of beef carcasses according to bone maturity, marbling and Bos indicus racial predominance, data from 1,417 carcasses processed in four Federal Inspection Type establishments were analyzed. The following variables were recorded: cavitary fat, rib eye area, dorsal fat thickness, hump length and height, marbling, and bone maturity. Using the variables marbling and bone maturity, the Basic Grade of Quality was estimated in accordance with the norm NOM-004-SAGARPA-2018. The hump height was used as a criterion to determine racial predominance, and four groups were generated from this information. Based on the recorded values, descriptive statistics, analysis of variance, comparison of means, and Tukey's test were determined. The hump height in each group was 7.19, 10.54, 14.38, and 20.11 cm (P<0.01), respectively. 82 % of the carcasses were predominantly Bos indicus. The hot carcass weight was 310.05 kg for group 1 vs 326.99 kg for group 4 (P<0.01). The rib eye area was 85.59 cm2 for group 1 vs 89.14 cm2 for group 2 (P<0.05). Of the total number of carcasses evaluated, 60 were classified as Supreme quality (4.23 %), 655 as Select quality (46.22 %), 621 as Standard quality (43.82 %), and 81 as Commercial quality (5.72 %). The beef carcasses in this study have mainly a Bos indicus breed component, and their Basic Quality Grade corresponded primarily to a greater number of carcasses with grade A bone maturity, but with less marbling.