|
|
||||||||
US Department of Agriculture2, Clay Center, NE 68933
Abstract
Four types of crossbred cows were used in each of two studies designed to estimate the metabolizable energy (ME) required to maintain weight or energy equilibrium of mature (9-yr-old), nonpregnant, nonlactating cows. The four cow types were chosen to represent cow types having moderate mature size-moderate milk production potential (Angus x Hereford, Hereford x Angus; AHX), large mature size-moderate milk production potential (Charolais x Angus or Hereford; CX), small mature size-high milk production potential (Jersey x Angus or Hereford; JX) and large mature size-high milk production potential (Simmental x Angus or Hereford; SX). In each of two consecutive years, four cows of each type were assigned randomly and fed individually either a low (113 kcal MEkg–.75 d–1), medium (178 kcal MEkg–.75 d–1) or a high (ad libitum) level of a corn silage-based diet for 140 d. Body composition of each cow was estimated by deuterium oxide dilution techniques at d 0 and 140 of each study and gains were calculated. The ME required to maintain weight or energy equilibrium was estimated for each type of cow. Estimates of ME required to maintain energy equilibrium (from the regression of log heat production, kcalkg–.75 d–1 on ME intake kcalkg–.75 d–1) were 130, 129, 145 and 160 kcalkg–.75 d–1 for AHX, CX, JX, and SX cows, respectively. Similar trends were observed when other models were used. Cow types with higher milk production potential had higher maintenance (kcalkg–.75 d–1) than cows with lower milk production potential. Cows of larger size had maintenance requirements (kcalkg–.75 d–1) similar to those of smaller size. Possible reasons for these differences as well as their potential impact on cow efficiency are discussed.
1 Cooperation of the Nebraska Agr. Exp. Sta., Univ. of Nebraska, Lincoln, is acknowledged.
2 ARS, NCR, MGPA, Roman L. Hruska U.S. Meat Animal Research Center. Mention of a trade name, proprietary product or specific equipment does not constitute a guarantee or warranty by the USDA and does not imply approval to the exclusion of other products that may be suitable.
This article has been cited by other articles:
![]() |
L. Calegare, M. M. Alencar, I. U. Packer, and D. P. D. Lanna Energy requirements and cow/calf efficiency of Nellore and Continental and British Bos taurus x Nellore crosses J Anim Sci, October 1, 2007; 85(10): 2413 - 2422. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. G. Jenkins and C. L. Ferrell Daily dry matter intake to sustain body weight of mature, nonlactating, nonpregnant cows J Anim Sci, July 1, 2007; 85(7): 1787 - 1792. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. S. Obeidat, M. G. Thomas, D. M. Hallford, D. H. Keisler, M. K. Petersen, W. D. Bryant, M. D. Garcia, L. Narro, and R. Lopez Metabolic characteristics of multiparous Angus and Brahman cows grazing in the Chihuahuan Desert J Anim Sci, September 1, 2002; 80(9): 2223 - 2233. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |