Preliminary observations on the influence of different feed protein levels on the blood profile of dairy cows
Hewett, C.; Ekman, L.; Lindell, L.
Acta Veterinaria Scandinavica 16(3): 471-473
1975
ISSN/ISBN: 0044-605X PMID: 1180198 Document Number: 86563
Three groups of lactating cows were supplied with isocaloric diets with protein at 75, 100 or 125% of the accepted Swedish standards, and blood was sampled during the 4th, 12th and 24th weeks of lactation. Fifteen constituents were estimated in each sample, with 8 to 13 observations in each group for separate occasions. There were significant differences among groups in serum total protein, urea N and protein-bound I but the differences were consistent only in the last 2. It is suggested that serum urea N provides a fairly exact reflection of protein intake when energy and roughage contents remain constant.