In order to determine the effect of weeds on artificial pastures, a study was conducted in central Côte d’Ivoire, on an artificial pasture of Panicum maximum C1 invaded by weeds. The flora of the pasture was determined from the floristic survey, and the degree of soiling and degradation was subsequently assessed from the weeds list and their cover. The feed ration for the cattle on this pasture was determined using the «shepherd’s collection» method. Pasture productivity was assessed by the full mowing method on plots previously protected. The results showed that the pasture studied was clean, composed of eight weed species, but very heavily degraded. The degree of degradation was 0.85. The cattle ration was composed mainly of grasses (94.5%), followed by legumes (5.4%). The specific contributions of Panicum maximum C1, a planted species, were 14.8% and 58.8%, respectively in the pasture and in the cattle diet. The species most appreciated by cattle remained Panicum maximum C1, with a selection index of 7.76. The potential forage productivity of the pasture was 5.73±0.08 tons of dry matter/hectare/year. This productivity rose to 10.35±0.11 tons of dry matter/hectare/year when the pasture was weeded and fertilised. The results obtained testify to the need to properly maintain and manage an artificial pasture.