ABSTRACT
The study was conducted to evaluate the effect of methanol root-bark extract of Anonna senegalensis against experimental Eimeria tenella infection in broiler chickens on the basis of performance (weight gain) and pathogenicity (oocyst production, lesion score and percentage mortality).
Phytochemical screening and acute toxicity studies of the extract were carried out using standard methods. Forty-two chicks were randomly assigned to seven experimental groups of six birds each. The experimental design included positive (infected untreated and negative (uninfected untreated) control groups.
Groups 1- 6 were inoculated orally with 2 × 104 sporulated oocysts at the 14th day of age except uninfected untreated group. In vitro anticoccidial activity test was performed by observing the effect of the extract on oocyst sporulation.
Oocysts count was done on 5th, 6th 7th and 8th 9th day after infection. Record of mortality was kept and postmortem of dead birds and lesion score were also performed. The phytochemical analysis of the methanol extract revealed the presence of alkaloids, tannins, saponins, glycosides, flavonoids, cardiac glycosides, steroid and terpenoids.
Acute toxicity study of the extract revealed that the LD50 methanol root bark of the extract of Anonna senegalensis (MREAS) is more than 5000 mg/kg . Inhibition of oocyst sporulation in vitro depended on the concentration of the extract, being highest at the maximum concentration of the extract.
Chicks medicated with A. senegalensis extract attained higher body weight than the non medicated challenged group. The highest mean weight gain after challenge with E. tenella at 42 days of age was high in group 5 (1450g). Lesion scores were significantly reduced in groups 4 and 5 (Group treated with 1600 mg/kg and amprolium), while groups 1 and 2 (200mg/kg and 400mg/kg treated groups) showed slight improvement in comparism with the former. Mortality of 5.5%, 2.8%. 2.8% and 16.6% was recorded for groups 1, 2, 3 and 6 respectively.
Histopathological findings revealed haemorrhages in the caeca, cellular infiltration, presence of endogenous parasitic stage and desquamation of epithelia. The oocysts output per bird in the treated groups were lower than that in the challenged control group. The reduced oocysts output at 1600 mg/kg dose level suggested that A. senegalensis could be beneficial for management and control of coccidiosis in broilers. This anticoccidial effect of the extract was, however, lower than those exhibited by amprolium.
REFERENCES
Abbas,R., Colwell, D.D., Gilleard, J.(2012). Botanicals: an alternative approach for the control of avian coccidiosis.World’s Poultry Science Journal 2012;68:203-215.
