Meat Science and Muscle Biology: Beef Quality

The aim of this study was to establish the feeding duration and dietary level of vitamin E offered to young bulls which does not affect performance but positively improve shelf-life of beef. Three experiments were carried out: E1) 1,000 IU vitamin E/animal per d fed during 37, 49, and 63 d; E2) 2,000 IU vitamin E/animal per d fed for 77 d and E3) 3,000 IU vitamin E/animal per d fed for 55 d. In E1, E2 and E3 a total of 36 (12, 549 ± 22.44; 12, 510.42 ± 27.48; and 12, 480.25 ± 19.99 kg), 24 (396.21 ± 24.39), and 24 (432.50 ± 23.81 kg) crossbred (Bos taurus × Bos indicus) young bulls were used, respectively. Average daily weight gain (ADG), dressing percentage (DP) as well as pH, water retention capacity (WRC), L* and chroma values and hue angle (hue°) of the rib eye (obtained between the 12th and 13th rib) were determined. Data were analyzed as a randomized block (E1) and completely randomized (E2 and E3) design using PROC GLM of SAS. Neither ADG nor DP were negatively affected (P ≤ 0.05) by the feeding duration or the dietary vitamin E level (E1, E2 or E3). Differences (P ≤ 0.05) in pH, L*, chroma and hue° in beef until d 63 (E1) of supplementation were observed in animals offered vitamin E. There were no (P ≥ 0.05) differences in beef quality traits on d 1 post-mortem, but differences (P ≤ 0.05) were found on d 8 and 16 post-mortem (E2), when the beef color was more stable. In E3 the beef quality traits were similar to those found in E2, suggesting that supplementing 3,000 IU of vitamin E/animal per day during 55 d had a similar effect than supplementing 2,000 IU vitamin E/animal per d during 77 d. In conclusion, it is feasible to supplement 1,000, 2,000, or 3,000 IU of vitamin E/animal per d without compromising the finishing performance. However, the vitamin E supplement has to be offered for at least 45 d before the slaughter to improve beef quality.