1993 Volume 46 Issue 5 Pages 385-391
Eight cows were selected from a high-yielding herd of 40 Holstein dairy cows whose average milk production was 10, 100 kg a year. Milk, blood and rumen samples were collected each month for one year to determine changes in these components in relation to lactation stage. The intake volumes of DM, TDN and DCP were 22.6 kg, 16.1 kg and 2.46 kg respectively, and average of milk production for 305 days, 10, 542 kg in the 8 cows. The components in milk and blood except glucose and NEFA showed peaks at the stage of the maximum lactation. The rumen components clearly differed during dry and lactation stages. These changes at the stage of lactation were within physiological ranges.