HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Van Horn, H. H. Articles by Graden, A. P. Search for Related Content PubMed PubMed Citation Articles by Van Horn, H. H. Articles by Graden, A. P.

Influence of Level and Source of Nitrogen on Milk Production and Blood Components¹

Department of Animal Sciences University of Kentucky, Lexington 40506

ABSTRACT

In Experiment 1, following a 22-day preliminary period 24 Holstein cows were used in a 70-day continuous feeding trial employing a 4 x 3 factorial design with four levels of urea (0, 82, 160, and 232 g urea/cow daily) and three levels of crude protein (average of 2.5, 2.2, and 1.7 kg crude protein/cow daily). There were no significant differences in milk production, milk composition, or body weight gains. Plasma urea nitrogen was increased by urea feeding (P < .01), and there was a linear response to crude protein level (P < .001). In Experiment 2, using 12 Jersey cows in a switchback design, urea supplementation of a corn silage and ground shelled corn ration (179 g/cow daily) increased milk production, body weight gains, and plasma urea nitrogen levels (P < .01) as compared with no added nitrogen. Nitrogen balances and plasma levels of glutamic acid were also increased (P < .10) by urea feeding. In Experiment 3, 12 Holstein cows were used in a 2 x 2 Latin-square design to compare nonprotein nitrogen as the only added nitrogen in a corn silage and ground shelled corn ration (423 g urea/cow daily) with an isonitrogenous ration providing 81 g urea/cow daily. Milk production was lower on high urea (P < .10), as were weight gains and plasma urea nitrogen (P < .01); nitrogen balances were higher (P < .10). Differences in milk composition and plasma amino acids were not significant.

¹ The investigation reported in this paper (no. 69-5-2) is in connection with a project of the Kentucky Agricultural Experiment Station adn is published with the approval of the director. This research was supported in part by Allied Chemical Company, New York, New York.

This article has been cited by other articles:

				S. E. Boucher, R. S. Ordway, N. L. Whitehouse, F. P. Lundy, P. J. Kononoff, and C. G. Schwab Effect of Incremental Urea Supplementation of a Conventional Corn Silage-Based Diet on Ruminal Ammonia Concentration and Synthesis of Microbial Protein J Dairy Sci, December 1, 2007; 90(12): 5619 - 5633. [Abstract] [Full Text] [PDF]