Table 4. Fibers ratio and cross-sectional areas of oxidative and glycolytic muscle fibers in the Longissimus thoracis muscle stained with the NADH-TR technique

Items	Treatments¹⁾				SEM	p-value
Items	Control	FA300	FA600	ZH	SEM	p-value
Fiber type ratios (%)
Oxidative	43.41	41.33	40.95	42.08	2.84	0.932
Glycolytic	56.58	58.66	59.04	57.91	2.84	0.932
CSA (µm²)
Oxidative	1,077.3^a	2,081.1^b	1,836.2^b	2,073.8^b	157.7	0.003
Glycolytic	1,619.2	2,255.1	1,738.5	2,229.9	267.7	0.274

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.