Do triclabendazole medicated molasses blocks have a role in control of Fasciola gigantica in smallholder cattle production in Lao PDR

Smallholder cattle production in many developing tropical countries including Laos is compromised by widespread endoparasitism, with limited farmer knowledge of parasites and facilities for administration of therapeutics. We report a pilot study examining the potential for triclabendazole provided in medicated molasses blocks offered to control Fasciola gigantica in smallholder cattle production. This study involved 241 cattle allocated into three groups: (1) triclabendazole (as Fasinex®, Novartis Animal Health Australia, Pty Ltd) medicated molasses blocks (MMB) with each tonne of MMB containing 0.5 kg triclabendazole; (2) unmedicated molasses blocks; and (3) a Control group. Data and faecal samples were obtained at Weeks 1, 4, 8 and 12 for faecal egg counts (FEC) determination. Reductions in FEC in the MMB group of 90.48% and a mean FEC of 4 ± 17 eggs per gram of faeces at 12 weeks post-treatment was observed, with liveweight increasing from 174.60 (±3.35) kg to 191.50 (±3.69) kg in Weeks 1 and 12, respectively (P = 001) and an average daily weight gain of 201 g/day. Reduction in FEC in the unmedicated molasses blocks group was also observed, by 28.78% and 18.96%, with liveweight increasing from 179.50 (±3.35) kg to 189.90 (±6.05) kg in Weeks 1 and 12 respectively (P = 0.3), with an average daily gain of 124 g/day. This study suggests that productivity was enhanced when triclabendazole was added to the blocks, delivering parasite suppression or potentially therapeutic doses on ad libitum feeding of the MMB. Although further work is required to establish the therapeutic potential of MMB, the use of MMB may offer a parasite management and nutritional supplementation strategy for smallholder farmers, particularly in Laos and other countries where unmanaged Fasciola spp. infestations reduce ruminant productivity and facilities for animal restraint to enable delivery of oral anthelmintics, are largely non-existent.