This study examined the effects of diets with two protein sources (oilseed cake meal (OSCM) and Leucaena leucocephala hay) on the performance of lactating goats that were fed a total mixed ration (TMR). Thirty Saanen milk goats were divided into two groups, which were fed one of the two TMRS, with or without Leucaena hay at 25% of the DM. The TMRs were formulated to be iso-nitrogenous, iso-energetic and iso-neutral detergent fibre, while using two sources of crude protein, namely i) Leucaena hay; and ii) oilseed cake meal OSCM from soybean, sunflower, and cottonseed. No significant differences were revealed in body condition score, bodyweight change, milk yield and milk composition, such as milk fat (%), milk lactose (%), somatic cell count (x 103 cells/mL) and milk protein (%) during the entire lactation period. In contrast, goats fed the TMR with Leucaena hay had a lower milk urea nitrogen (mg nitrogen/dL) level than those fed the control diet (with OSCM). It was concluded that replacing a proportion of oilseed cake meal with Leucaena in Saanen milk goats fed TMR does not negatively influence milk production and composition.