Table 5. Fibers ratio, cross sectional areas and density of slow, intermediate and fast muscle fibers in the Longissimus thoracis muscle stained with the ATPase technique

Items Treatments1) SEM p-value
Control FA300 FA600 ZH
Fiber type ratios (%)
 Slow 12.34 9.19 10.72 12.23 1.67 0.523
 Intermediate 36.53 41.52 33.65 37.84 7.66 0.906
 Fast 51.11 49.28 55.62 49.91 6.96 0.915
CSA2 (µm2)
 Slow 2,349 2,448.3 2,303.8 3,234.4 306.4 0.169
 Intermediate 1,477.0 1,526.0 1,512.5 2,377.8 332.7 0.223
 Fast 1,760.8a 1,748.8a 1,350.5a 2,362.1b 255.9 0.049
Fiber density (fibers/50,000 µm2) 23.14 17.77 26.02 20.15 2.67 0.207
Basal diet without additive (Control); basal diet plus 300 mg of FA d−1 (FA300); basal diet plus 600 mg of FA d−1 (FA600); basal diet plus zilpaterol hydrochloride at 6 mg d−1 (ZH). n = 4.
Means with different superscripts in same row, indicate significant differences (p < 0.05).
FA, ferulic acid; ZH, zilpaterol hydrochloride; CSA, cross sectional area.