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 Woodford, S. T. Articles by Davis, C. L. Search for Related Content PubMed PubMed Citation Articles by Woodford, S. T. Articles by Davis, C. L.

Water Dynamics of Dairy Cattle as Affected by Initiation of Lactation and Feed Intake¹

Department of Dairy Science, University of Illinois, Urbana 61801

ABSTRACT

Effects of lactation and feed intake on sizes and half-lives of body water pools were investigated in four Holstein cows in a thermoneutral environment. Various markers were administered, on average, 24 days prepartum (Period 1, feed intake fixed to average of consumption after offered at a rate ensuring 10% refusal), 24 days postpartum (Period 2, restricted to intake in Period 1), and 42 days postpartum (Period 3, feed again offered at a rate ensuring 10% refusal). Total body water decreased from period 1 to 2; however, it did not change as a percent of body weight. Estimated body water half-lives and fluxes for the three periods were 7.5, 3.7, and 2.9 days; and 42, 66, and 87 liters/day. Increased water intake during lactation closely matched water secreted in milk. Empty body water, estimated by a two-compartment, four-parameter model, as a percent of body weight did not change across periods. Lactation and increased feed intake decreased half-life of body water. Plasma volume increased as a percent of body weight because of loss of body weight in early lactation; however, extracellular volume tended to decrease with body weight. Initiation of lactation and feed intake during lactation affect water dynamics of the dairy cow.

¹ Supported by Illinois Agricultural Experiment Station, Hatch 35-0360.

This article has been cited by other articles:

				J. M. Lukas, J. K. Reneau, and J. G. Linn Water Intake and Dry Matter Intake Changes as a Feeding Management Tool and Indicator of Health and Estrus Status in Dairy Cows J Dairy Sci, September 1, 2008; 91(9): 3385 - 3394. [Abstract] [Full Text] [PDF]