Shear force of meat from young bulls finished in feedlot with high-concentrate diet and cinnamon essential oil (Cinnamomum zeylanicum)

The essential oils are natural additives and may be used in animal production. The objective of study was to evaluate the shear force of meat from young bulls finished in feedlot with high-concentrate diet and cinnamon essential oil. The experiment was carried on the State University of Maring?, at the experimental farm station at Iguatemi city, Paran?, Brazil. Twenty-four (?/₂ Brown Swyss - ?/₂ Nellore) young bulls with 10 ? 2.2 month-old and an initial average body weight (BW) of 218.0 ? 15.71 kg were used in a complete randomized design, assigned to individual pens. The basal diet consisted of 90% concentrate and 10% of sugar cane pellets offered ad libitum. The diets were: CON - control, CIN35 - 3500 mg/animal/day of cinnamon leaf essential oil, and CIN70 - 7000 mg/animal/day of cinnamon leaf essential oil. After 187days in feedlot, the young bulls reached an average of 443.5 ? 26.2 kg BW, and were slaughtered at a commercial beef plant. The carcasses were stored in a chilling chamber at 4^oC. After twenty-four hours, Longissimus dorsi muscle samples were taken between 6^th and 13^th ribs. Two centimeters thick steaks were cuts between 12^th to 13^th ribs, vacuum packaged individually and assigned to 1, 7 and 14 days ageing periods. For the texture analysis, each steak was cooked in a pre-heated grill until reaching an internal temperature of 72 ?C, using a texture analyzer Stable Micro Systems TAXT Plus (Texture Technologies 15 Corp., UK) with a Warner-Bratzler cell. The meat was cut into pieces of 1 cm² cross-section, perpendicular to the direction of muscle fibers. The data were submitted to variance analysis on SPSS version 21.0 Statistic(R). The inclusion of cinnamon essential oil in diet of animals did not influence meat texture. The values for CON, CIN35 and CIN70 were 5.23, 5.52 and 4.89 Kgf for 1 day ageing (P = 0.624), 3.54, 4.45 and 3.34 for 7 days ageing (P = 0.169) and 3.15, 3.37 and 2.82 for 14 days ageing (P = 0.540), respectively. On the order hand the ageing was significant factor, the shear force was average reduced by 60% from the 1st to the 14th day. Inclusion of cinnamon essential oil has no negative effect in shear force, but the ageing improved the tenderness of the meat.