Anthelmintic activity of <i>Leucaena leucocephala</i> var. <i>tarramba</i> leaf extracts against ruminant gastrointestinal parasites

Abstract With the growing resistance of parasites to most currently available anthelmintics and increasing concerns about anthelmintic residues in animal products and the environment, there is a heightened interest in exploring plant-based alternatives. This study aims to evaluate the anthelmintic properties of Leucaena leucocephala var. tarramba leaf extracts against gastrointestinal parasites in ruminants, examining their effects on internal parasites in vitro and in vivo. For the in vitro analysis, eggs isolated from fresh fecal samples of worm-infected goats were incubated with varying concentrations (0.25% to 1%) of the leaf extract. The best extract concentration in the in vitro test was then selected and formulated into a bolus for use in the in vivo test on ten cattle aged 7 to 12 months. The cattle were randomized into two groups: treatment and control, with the treatment group receiving the leaf extract and the control group receiving a commercial anthelmintic. In vitro tests revealed that a 1% concentration of Tarramba leaf extract significantly inhibited egg hatching, showing comparable efficacy to commercial anthelmintics. In vivo tests on Bali cattle demonstrated that the extract reduced parasite prevalence by 60% over eight weeks, though this was less effective than the 80% reduction achieved with commercial anthelmintics. These findings suggest that Leucaena leucocephala var. tarramba could offer a sustainable alternative to synthetic anthelmintics, reducing the environmental impact and risk of drug resistance in parasite control for livestock.