The general aim of this study, which focused on goat fattening, was to investigate, as an initial trial, the weight performance of goats, about which very little is known, with a view to developing sustainable technical and economic proposals for extensive Sahelian farming systems. The methodology was based on weekly measurements of the bucks’ weight performance in an experimental batch of 11 bucks fed a ration based on local feed resources and a control batch. The control lot was monitored in parallel under the normal conditions of the area’s usual extensive rearing practices. The results showed that the animals in the control batch did not regain weight, with a 3% loss in body weight. In the experimental batch, body weight varied progressively with an average increase of 7 kg per buck. The Consumption Index, which ranged from 6 to 18 kg of dry matter per kg of growth depending on the duration of fattening, shows the sharp efficiency of goats in converting local fodder resources into animal protein. The physical and ethnic characteristics of the animals had a significant influence on their increased economic value. Older, larger and medium-weight Sahelian bucks contributed more to maximising foreign exchange. The average daily gain and gross profit were higher when the duration of fattening was limited to six weeks. After this period, the profit (2047 F CFA on average per billy-goat) fell linearly, resulting only in economic losses from the 9th week onwards. Taking into account the optimum duration and the criteria for choosing the animal will lead to overall improvements in the profitability of fattening goats.