Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science


Forage evaluation for utilization by ruminants can be made by several methods. The conventional in vivo digestibility trials, in vitro dry matter digestibility methods and a number of chemical component analyses have been tested quite extensively in the last 25 years. The in vivo digestibility trial has been the traditional method for feed evaluation, but performance of such a trial is costly and tedious and the resulting total digestible nutrients or digestible energy values have been criticized as being an incomplete measure-of feed value. There are many laboratory feed analyses methods available today. However, in vitro digestibility data have been shown to correlate best with in vivo digestibility data with some restrictions, the most important being inconsistent results when attempting to predict intake. Some of the chemical component analyses, on the other hand, may indicate intake to some degree but do not predict digestibility as well as in vitro digestion analyses. It has been suggested that other laboratory chemical analyses of forages such as acid-detergent fiber, Crampton and Maynard cellulose, acid-detergent lignin, crude protein, neutral detergent fiber or ash, alone or in combination with in vitro digestibility data, may indicate forage quality as efficiently as in vivo trials. This presents the possibility of obtaining more intimate relationships between these chemical component analyses and in vivo digestibility than has so far been achieved. Investigations were conducted with these thoughts in mind to determine the following specific objectives: 1. To determine the effects of field storage on forage quality analyses parameters with two different large hay packaging systems. 2. To determine selected chemical component analyses or combinations of these analyses which may be used with IVIMD in order to obtain a better estimate of in vivo digestibility than in vitro data alone. 3. To incorporate the chemical component analyses which best correlate with in vitro digestibility into a regression equation predicting IVDMD which in turn estimates in vivo digestibility data.

Library of Congress Subject Headings


Hay -- Handling



Number of Pages



South Dakota State University