Effects of Asiatic pennywort (Centella asiatica L. Urban) leaves, a replacement of antibiotics, on growth performance, mucosal enzyme activities of the small intestine and nutrient digestibility in broiler chickens

Abstract

The objectives of this investigation were to study the effect of Asiatic pennywort (Centella asiatica L. Urban) leaves, a replacement antibiotics, on growth performance, mucosal enzyme from the small intestine and nutrient digestibility in broilers. In experiment 1, a preliminary study on the effect of Asiatic pennywort leaves on growth performance was examined. Four hundred and thirty two broilers were allocated into 9 treatments: T1, basal diet (control); T2, T4, T6, T8, basal diet plus crude powder of Asiatic pennywort leaves at the level of 1.67, 3.33, 6.67, 10.00 g/kg feed; T3, T5, T7, T9, basal diet plus crude extract of Asiatic pennywort leaves at the level 0.40, 0.80, 1.60, 2.40 g/kg feed. Body weight and feed intake were measured at days 21 and 42 of the experiment. In experiment 2, the effect of Asiatic pennywort (leaves and stem) on growth performance, brush border enzymes from the small intestine and nutrient digestibility were studied. Seven hundred and ninety two broilers were allocated into 6 treatments: T1, basal diet (control): T2, T4, basal diet plus crude powder of Asiatic pennywort at the level 20, 40 g/kg feed; T3, T5, basal diet plus crude extract of Asiatic pennywort 3.6, 7.2 g/kg feed; T6, basal diet plus antibiotic 2.5 ppm. At days 21 and 42 of the experiment, body weight and feed intake were measured, six broilers in each group of each period were randomed selected and the contents of jejunum (J), ileum (I) and caecum (CE) were collected for pH determination. Jejunal mucosa were collected for the determination of disaccharidase and peptide hydrolase activities. Ileal mucosa were collected for the determination of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) concentrations. At days 25 and 46 of the experiment, ileal digesta from twelve broilers in each treatments were randomed collected for protein and fat digestibility. At day 21 of experiment 1, it was found that the broilers supplemented with 1.67 g/kg feed of crudepowder and 0.40 g/kg of crude extract of Asiatic pennywort had significant (P<0.05) higher weight gain and average daily gain than those of the control group. However, growth performance determined at day 42 of the experiment were not different among treatment. In the experiment 2, it was found that Asiatic pennywort given regardless of forms and doses tended to decrease pH in various parts of the small intestine, but did not affect the disaccharidase enzyme activities. While, at day 42, it was found that the broilers supplemented with 40 g/kg feed of crude powder, 7.2 g/kg feed of crude extract of Asiatic penntwort and antibiotics had significant (P<0.05) higher peptide hydrolase activities than that of the control group. For digestibility at day 25. it was found that the broilers supplemented with 3.6 and 7.2 g/kg feed of crude extract of Asiatic pennywort had significant (P<0.05) higher protein digestibility that that of the control group. While, the broilers supplemented with 3.6 g/kg feed of crude extract of Asiatic pennywort had significant (P<0.05) higher fat digestibility that those of the other groups, except that of the control group. Moreover, it was found that the Asiatic pennywort supplementation did not affect protein, DNA and RNA concentrations of the small intestine. In conclusion, growth performance of broilers in Asiatic pennywort supplementation groups were not significantly diffeent from antibiotic group. However, Asiatic pennywort had some effects on intestinal pH, peptide hydrolase activities and nutrients digestibility, Further studied are required to examine whether Asiatic pennywort can be used to replace antibiotic growth promoter in poultry.