Individual feeds(n-4), orts(n-48) and feces(n-48) (12 cows in 4 periods) samples were dried in forced air oven for 72h and ground to pass through 1 mm screen(Wiley mill, H.Thomas, Philadelphia, NY), and then were placed into cm x 5 cm filter bags(20 mg of DM/cm2) that had previously been weighed.