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 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 Fox, D. G. Articles by O'Connor, J. D. Search for Related Content PubMed Articles by Fox, D. G. Articles by O'Connor, J. D.

Adjusting Nutrient Requirements of Beef Cattle for Animal and Environmental Variations¹

Cornell University, Ithaca, NY 14853

Abstract

Requirements determined under standardized conditions are applied indiscriminately to an infinite combination of animal, management and environmental conditions. A model was developed to adjust maintenance requirements for various combinations of temperature, wind, hide, hair coat, activity and previous and present planes of nutrition. Maintenance energy requirements range from values equivalent to National Research Council (NRC) recommendations (no stress) to over four times NRC values under extreme environmental conditions, according to this model. Expanding NRC requirement equations for growing cattle from five categories (three for steers and two for heifers) to 162 categories for each sex class helps minimize the risk of an error in describing the cattle. A model was developed to expand NRC requirements for beef cows from two constant amounts of milk production to six lactation curves; it calculates monthly lactation requirements for nine mature sizes of cows. To aid in allocating forage, a system was presented for determining metabolizable energy requirements for the beef cow-calf unit. Requirements for the cow-calf unit range from equivalent to NRC during early lactation to values 70% higher than NRC estimates near the end of lactation; errors in pasture allocation can reduce weaning weight severely.

¹ Invited paper presented in the symposium "Determining the Nutrient Requirements of Ruminants," ASAS Ann. Meeting, Midwest Section, Des Moines, Iowa, March 23–25, 1987.

This article has been cited by other articles:

				A. H. Abdelsamei, D. G. Fox, L. O. Tedeschi, M. L. Thonney, D. J. Ketchen, and J. R. Stouffer The effect of milk intake on forage intake and growth of nursing calves J Anim Sci, April 1, 2005; 83(4): 940 - 947. [Abstract] [Full Text] [PDF]

				C. R. Johnson, D. L. Lalman, M. A. Brown, L. A. Appeddu, D. S. Buchanan, and R. P. Wettemann Influence of milk production potential on forage dry matter intake by multiparous and primiparous Brangus females J Anim Sci, July 1, 2003; 81(7): 1837 - 1846. [Abstract] [Full Text] [PDF]

				T. N. Bodine and H. T. Purvis II Effects of supplemental energy and/or degradable intake protein on performance, grazing behavior, intake, digestibility, and fecal and blood indices by beef steers grazed on dormant native tallgrass prairie J Anim Sci, January 1, 2003; 81(1): 304 - 317. [Abstract] [Full Text] [PDF]