Targeted selective treatment against gastrointestinal nematodes in goats under Mozambican conditions

Gastrointestinal nematodes severely constrain goat production and farm resilience worldwide, particularly due to anthelmintic resistance. This study evaluated targeted selective (TST) and strategic treatment (ST) regimes on 16 Landim goat farms in Mozambique from June 2022 to November 2023, using the Five Point Check© to indicate nematode impacts and guide TST decisions. Six farm visits were conducted to apply ST (8 farms, 175 goats) or TST (8 farms, 186 goats) and obtain strongyle egg counts and animal weights. Treatment efficacy (fenbendazole 10 mg/kg bw; Panacur®) was evaluated at the start and end of the study using faecal egg count reduction tests (FECRTs) and in vitro egg hatch tests (EHT). Strongyle populations on 7/16 of farms were fenbendazole-resistant based on FECRT, with four on TST and three on ST farms and little change over the study period. A strong negative correlation was observed between egg hatching rates at 0.3 μg/ml thiabendazole and FECRT outcomes (Pearson's r = -0.97, p = 0.001), corroborating the presence of resistance. At the end of the study, both TST and ST groups improved or maintained their FAMACHA scores. Weight gain was higher in the TST than the ST group, despite 94% fewer treatments. Only 51 (30.1%) of TST goats required treatment, resulting in just 56 treatments in total, whereas all ST goats received five treatments. Long-term studies conducted under diverse climatic and management conditions are recommended to further validate the applicability of TST in diverse goat production systems in Africa to support livelihoods and climate adaptation.