Five lactating dairy cows were used in a cross-over design to determine if increased hepatic ureagenesis affected hepatic removal of amino acids (AA). Hepatic ureagenesis accounted for all urea entry rate (measured with a 3-d infusion of ¹⁵N¹⁵N-urea) and both increased with urea supplementation. Neither liver removal of essential AA or milk protein yield was affected by urea supplementation. Gut entry rate and its partition between anabolic and catabolic fates were also unaltered by treatment. Saliva contributed to 0.31 to 0.50 of urea gut entry rate. In cows producing 32 kg/d of milk and fed a diet supplying 157 g CP / kg DM, increased hepatic ureagenesis did not result in decreased post-liver supply of essential AA and subsequent milk protein yield.