Kidney function, but not nitrogen excretion differs between Brown Swiss and Holstein dairy cows

Brown Swiss (BS) cows have greater urea concentra- tions in milk and blood compared with Holstein (HO) cows. We tested the hypothesis that BS and HO cows differ in kidney function and nitrogen excretion. Blood, saliva, urine, and feces were sampled in 31 multiparous BS and 46 HO cows kept under identical feeding and management conditions. Samples were collected at dif- ferent lactational stages after the monthly DHIA control test-day. To test the glomerular filtration rate (GFR) and urea...