The kinetic parameters of the dry matter ruminal degradation of some concentrates and forages were estimated by in situ, in vitro, and by the cummulative gas production techniques through anaerobic incubations. The grasses Tifton-85, elephant, palisade, signal, and molasses, the perennial soy, and the concentrates soyabean meal, cottonseed meal, wheat bran, corn meal and ground sorghum were studied. The kinetic interpretations of the in situ and in vitro incubations were performed by using the decreasing logistic model B.(c.exp(-p.t)-p.exp(-c.t))/(c-p)+I, and the cummulative gas production data were analyzed by using the dual pool logistic model V_f = V_f1/(1+exp(2+4m₁(L-T))) + V_f2/(1+exp(2+4O₂(L-T))). Between the gravimetric techiniques, the in vitro incubations resulted in lower variation when compared to the in situ, thus the former could be routinelly used to estimate the kinetic parameters of the feeds degradation. The gas production was the technique that resulted in the lowest variation among the studied methods, specially after 12 hours of incubation. The soluble (a) and the indegradable (I) fractions could be obtained by the in vitro incubation, and the degradation rates could be accuratelly estimated by the gas production techniques. The combined characteristic of the feeds could be realized by cheap techniques, reducing the use of cannulated animals.