The use of mixed ration silage (MRS) provides animals with a diet formulation that meets their nutritional requirements. This study aimed to evaluate the fermentative profile, losses, chemical composition and in vitro dry matter digestibility of mixed ration silages, including babassu by-products as a feed alternative for dairy cows. A completely randomized design was used, with four treatments and five replications, which were composed of TGS: Tanzania grass silage; MRSS: Tanzania grass silage with corn and soybean meal; MRSF: Tanzania grass silage with corn, soybean meal and babassu flour; and MRSC: Tanzania grass silage with corn, soybean meal and babassu cake. There was a significant difference between MRS and TGS (p 3-N) and non-fibre carbohydrate (NFC) content, lower values were observed in the MRS (p < 0.001). The babassu by-products, cake and flour, can replace corn by up to 50% of the total ration silage with Tanzania grass, meeting the nutritional requirements of dairy cows.