Revista Brasileira de Zootecnia
On-line version ISSN 1806-9290
SILVA, Saulo da Luz e; LEME, Paulo Roberto; PEREIRA, Angélica Simone Cravo and PUTRINO, Soraia Marques. Correlations among carcass characteristics taken by ultrasound and after slaughter in Nellore steers fed high concentrate diets. R. Bras. Zootec. [online]. 2003, vol.32, n.5, pp. 1236-1242. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982003000500026.
The objective of this work was to estimate the correlations among measurements taken in vivo with ultrasound equipment with some carcass characteristics measured after slaughter. Twenty two Nellore steers, with average shrunk body weight of 279 kg and 24 months of age, were fed by 98 days with high concentrate diets. The shrunk body weight, the ribeye area (AOLU) and the fat thickness (EGSU) over the Longissimus dorsi muscle between 12ª and 13ª ribs, were measured at 28 days intervals. Real-time ultrasound equipment Piemedical Scanner 200 VET, with 18 cm linear array transducer was utilized. After the slaughter, the hot carcass weight (PCQ) and the kidney, pelvic and inguinal fat (GRPI) were weighted and the dressing percentage (RC) calculated. After 24 hours of cooling the ribeye area (AOLC) and the fat thickness (EGSC) were measured. Both the AOLC and the EGSC were underestimated by ultrasound measurements. The Pearson correlation coefficients for ribeye area and backfat thickness, measured in the carcass and with ultrasound, were 0,74 and 0,87, respectively. The coefficient between RC and AOLU was 0,27; 0,42 between RC and AOLC, -0,30 between RC and EGSU and -0,29 between RC and EGSC. The GRPI presented a 0,48 correlation coefficient with EGSC and EGSU. The Spearman correlation was estimated between AOLU and AOLC and EGSU and EGSC, and the values were 0,89 and 0,77, respectively.
Keywords : ribeye area; in vivo evaluation; beef cattle; backfat thickness; Nellore; ultrasound.