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 Google Scholar Google Scholar Articles by Tinnimit, P. Articles by Thomas, J. W. Search for Related Content PubMed Articles by Tinnimit, P. Articles by Thomas, J. W.

Forage Evaluation Using Various Laboratory Techniques¹

Michigan State University, East Lansing 48824

Abstract

Forages from tropical and temperature regions were evaluated by chemical analyses, in vitro rumen fermentation and various enzymatic incubations. Commercial cellulose preparations had differing activities for various cellulose substrates. Cellulose, amylase, pepsin or these enzymes in sequential incubations predicted in vivo digestible dry matter (DDM) of alfalfa or grasses with correlations of .52 to .90 and standard errors of estimate (See) of 2.4 to 5.6. Use of buffer alone approached this accuracy. In vivo DDM of temperate forage was predicted from cell components (cell walls (CW); acid detergent fiber (ADF) or ligin (L)) with correlations of .70 to .86 and See of 3.3 to 5.6. The two stage in vitro fermentation as DM or organic matter disappearance was the method of choice for predicting DDM of both grasses and legumes with See of 1.8 to 4.4 and correlations of .88 to .98. Use of multiple in place of simple linear regression equations using above laboratory values did not appreciably increase prediction accuracy. Temperate forages had greater in vitro dry matter disappearance (IVDMD), crude protein (CP), and lignin than tropical forages examined by ratios of 1.05, 1.28 and 1.14, respectively. These tropical forages were greater than temperate forages by ratios of 1.11, 1.05 and 1.21 for cell walls (CW), acid-detergent fiber (ADF) and ash, respectively. Values for IVDMD and CP of five temperate grasses grown in Michigan decreased with advancing maturity at the rates of .42 and.13 percentage unit per day, whereas those for three tropical grasses grown in Thailand decreased at the lower rates of .09 and .09% unit per day, respectively.

¹ Published with approval of Director of Agricultural Experiment Station as Journal Article No. 7452

² This Paper is Part of a Dissertation Submitted by Die Senior Author in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy.

³ Present address: Rubber Research Centre, Hat Yai, Thailand.

⁴ Department of Dairy Science (where reprint can be obtained).