<b>Carcass characteristics, chemical and fatty acid composition of <em>Longissimus</em> muscle of Purunã bulls slaughtered at 18 or 24 months of age</b> - doi: 10.4025/actascianimsci.v32i3.7274

Abstract

This study was carried out to evaluate carcass characteristics, chemical and fatty acid composition of the Longissimus muscle of 78 Purunã bulls (39 bulls/treatment) slaughtered at 18 or 24 months old. The experimental design was completely randomized. The bulls were distributed into two systems: 1) Finished in feedlot 13 to 18 months old (T18), or 2) Finished in feedlot from 21 to 24 months old (T24). The diet, roughage:concentrate ratio of 52:48 (dry matter basis), contained 12% crude protein and 72% total digestible nutrients. The T18 system showed lower (p < 0.05) conformation (12.46 vs. 13.41 points), higher (p < 0.05) subcutaneous fat thickness (3.82 vs. 3.11 mm), lower (p < 0.05) Longissimus area (66.17 vs. 70.87 cm²), lower (p < 0.05) muscle percentage (60.64 vs. 64.26%) and higher (p < 0.05) fat percentage (23.56 vs. 20.00%). Moisture (73.27%), ash (1.05%), crude protein percentages (22.56%) and total cholesterol content (36.47 mg/100 g of muscle) were similar (p < 0.05) between both slaughter ages. The total lipid percentage was higher (p < 0.05) for the T18 system (1.61 vs. 1.33%). Longissimus muscle fatty acid composition was not influenced (p < 0.05), with exception of C18:1 n-9 and C18:3 n-3, which were lower (p < 0.05) for the T18 system. Saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, n-6, n-3 percentage and PUFA/SFA and n-6/n-3 ratio did not change (p < 0.05) according to slaughter age.