Dry matter and protein disappearance of four compounded cattle feeds in the form of pellets with different composition were studied using nylon bag technique. From the protein disappearance data at different hours of incubation in the rumen, the constants ‘a’, ‘b’ and ‘c’ of the exponential equation p = a + b(l—e-ct), were derived iteratively. Rate of degradability was linked with the rumen outflow rate to arrive at the effective protein degradability (p) using the equation p = a + be/c + k. Effective degradability of each concentrate mixture was calculated at rumen outflow rates ranging from 0.01 to 0.10/h. The effective protein degradability of concentrate mixtures I, II, III and IV were 73.56, 71.40, 62.00 and 75.58 per cent at 0.05/h rumen outflow rate.
