[Swiss veterinary research and development project in the Gambia: the point of view of the breeder concerning control of helminthiasis in livestock].

The epidemiology of nematodes in livestock in The Gambia was assessed. A prophylactic biannual treatment was then tested on cattle and sheep. This treatment resulted in a significant improvement in the reproductive performances (sheep: lambings/year increasing from 1.04 to 1.22 and lambs/lambing increasing from 1.11 to 1.19; cattle: age at first calving decreasing from 58 to 50 months) and, in cattle, a significant improvement of the weight (varying between 8% and 17% in 1 to 4 year old animals). A socioeconomic study conducted in parallel showed that the treatment in cattle is on average profitable (benefit/cost ratio of 1.14) but remains a risky investment which should not be generalised (benefit/cost ratio would have been below 1 in more than half of the participating herds). In sheep, the benefit/cost ratio is high (2.47) with a low risk of losses (< 10%). The obstacles to the adoption by farmers of such a treatment and the usefulness of a pluridisciplinary approach in similar studies are then discussed.