Effect of RLS on the serum IL-1β, IL-6 and TNF-αin broilers. NCO represents the control broilers on day 28 and 56, respectively; ANT represents the broilers supplemented with 30 mg/kg bacitracin on day 28 and 56, respectively; RLS1 represents the broilers supplemented with 500 mg/kg RLS on day 28 and 56, respectively; RLS2 represents the broilers supplemented with 1,000 mg/kg RLS on day 28 and 56, respectively. Diverse lowercase letters show significant differences between treatments (P < 0.05). Values means n = 8 for the analysis of serum inflammatory. Data are means ± SD. Abbrevaition: RLS, rhamnolipid.