Comparative study on the prebiotic effects of Inulin and aqueous extract of Vernonia amygdalina on growth and intestinal morphometry of broiler chicken (Cobb strain)

Antibiotic misuses aimed at improving growth performance in poultry production have resulted to widespread of antimicrobial resistance (AMR) in poultry. Recently, prebiotics are accepted as preferred alternatives. The aim of this study was to compare the prebiotic activities of a known and commercially available substance, inulin and a locally available plant, Vernonia amygdalina (bitter leaf) on growth performance and intestinal morphometry of broiler chicken. Sixty day-old broiler chicken (Cobb strain) employed in this study were acclimatized for three weeks and randomly divided into six treatment groups and a control. The treatment groups were further divided into the Inulin group treated with 5, 10 and 20 mg/kg of Inulin and the Vernonia group treated with 50, 100 and 200 mg/kg of Vernonia amygdalina (VA) aqueous extract. After three weeks of prebiotic administration, samples were collected to ascertain effects on body weight, intestinal length and histomorphological measurements of the intestinal villi and crypts were determined. Results showed that body weight did not differ significantly (p>0.05) with both prebiotic administration but a higher weight gain of 1.216 kg and 1.334kg were observed with 20 mg/kg inulin and 100 mg/kg VA administration respectively. Administrations of both prebiotics were not found to significantly affect intestinal length measurement (p>0.05). However, they were found to significantly increase (p<0.05) the intestinal villus height and crypt depth in the treatment groups when compared to the control group. Increased villus height, which may suggest enhanced absorptive function, were improved at dosing broilers with 20 mg/kg inulin and 100 mg/kg VA. Concluding, the effects of both prebiotics; inulin and Vernonia amygdalina aqueous extract on enhancement of growth performance and intestinal function are comparable. Where the effect of inulin was observed to be dose dependent, the effects of Vernonia amygdalina aqueous extract was observed to decline above 100 mg/kg.