The in situ technique has been used widely for estimating ruminal nutrient degradation and to provide estimates of both the rate and extent of disappearance of feed constituents (Mehrez and Ørskov, 1977), because it is a relatively simple, low-cost method compared with methods involving intestinally cannulated animals. This technique provides a useful means to estimate rates of disappearance and potential degradability of feedstuffs and feed constituents. The technique involves suspending bags containing different feedstuffs in the rumen and measuring nutrient disappearance at various time intervals. Hence, it also may provide an advantage compared with laboratory methods because it involves digestive processes that occur in the rumen of a living animal; however, several factors affect estimates of nutrient digestion and need to be controlled for this technique to be standardised. Feeding by-products to dairy cows and other livestock will probably continue to increase in the future. By-product feeds fed to dairy cows and other livestock prevents a waste disposal problem for industry and reduces the amount of concentrate that must be included in the diet to ensure maximum animal performance. The object of this study was to estimate in situ crude protein degradability of dried grape by-product (DGB), noodle waste (NW), tomato pomace (TP), apple pomace (AP) and grape pomace (GP) using the in situ technique.