JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Dairy Science Vol. 82 No. 9 1943-1949
© 1999 by American Dairy Science Association ®
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Belyea, R.
Right arrow Articles by Ellersieck, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Belyea, R.
Right arrow Articles by Ellersieck, M.

Effect of Year and Cutting on Equations for Estimating Net Energy of Alfalfa Forage

R. Belyea 1, R. Restrepo 1, F. Martz 1, and M. Ellersieck 1

1 Department of Animal Sciences, University of Missouri, Columbia 65211

The net energy of lactation (NEL) concentration of forages is important for formulating diets. The equations presently used to estimate NEL of alfalfa are based on limited data. Our objective was to determine whether a larger database would provide more relevant equations. One hundred eighty samples of alfalfa were taken over four cuttings and 2 yr, combined into 45 composites and analyzed for neutral detergent fiber, acid detergent fiber (ADF), and in vitro true digestibility. Finally, NEL values were estimated using neutral detergent fiber and in vitro true digestibility. Prediction equations were obtained by regressing NEL upon ADF concentration.

Changes in NEL with age of alfalfa at harvest differed with year and cutting. Estimation of NEL would be more accurate with equations specific for cutting and year, but such an approach would be difficult to use in practice. When data were pooled across years, four cutting-specific equations were obtained; these had different intercepts and slopes and gave different NEL values for a given ADF content. Differences among estimates of NEL increased as ADF increased. Data were combined across years and cuttings to give an overall equation that was similar to published prediction equations. Compared with NEL values from the cutting-specific equations, the overall equation underestimated NEL for first cutting alfalfa and overestimated NEL of second cutting alfalfa. A lack of precision in estimating NEL could equate to 1.5 to 2.5 kg of milk/d. Cutting specific equations should be used to estimate the NEL of first- and second-cutting alfalfa; NEL of the third and fourth cuttings could be estimated using an overall equation.

Key Words: net energy of lactation • alfalfa • forage quality • digestibility

Submitted on August 28, 1998
Accepted on April 5, 1999




This article has been cited by other articles:


Home page
 Agron. J.Home page
D. P. Malinowski, W. E. Pinchak, B. A. Kramp, H. Zuo, and T. J. Butler
Supplemental Irrigation and Fall Dormancy Effects on Alfalfa Productivity in a Semiarid, Subtropical Climate with a Bimodal Precipitation Pattern
Agron. J., April 4, 2007; 99(3): 621 - 629.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1999 by the American Dairy Science Association ®.