Figure 4.

Breast muscle histological cross sections of broiler chickens supplied with GHBP: control (A), GHBP100 (B), GHBP200 (C), and GHBP300 (D). Muscle fiber’s characteristics: myofiber area (µm²) (E) and myofiber number per field (F). GHBP: growth hormone-boosting peptide. Data are expressed as means ± SE. Bars with different letters above them correspond to values that were significantly different (p < 0.05). Control: basal diet without GHBP; GHBP100: basal diet plus GHBP at a level of 100 μg/kg; GHBP200: basal diet plus GHBP at a level of 200 μg/kg; GHBP300: basal diet plus GHBP at a level of 300 μg /kg. ^a,b,c, Means with different superscripts within the same row differ significantly (p < 0.05).