The effect of tropical grasses inclusion in dairy rations on milk composition is not consistent across studies. Previous reports show that inclusion of 10% of the ration DM from T85 hay increased milk fat percentage (Castro et al., 2008), but increasing the proportion of T85 from 15 to 23% DM reduced milk protein percentage and yield of milk fat, and protein as milk yield declined (West et al., 1999). Milk fat and protein percentage were not different for Holstein × Cebu crossbred cows fed diets based on either BG or AH (Moreira et al., 2001). Overall, simultaneous reduction of milk yield and fat and protein yield seems to have been associated with lower energy and fermentable OM intake when levels of T85 in the ration have exceeded 15% of the DM.