Skip to main content
ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #192329
Title: EVALUATING IN VITRO CELL WALL POLYSACCHARIDE DIGESTIBILITY OF HIGH-FIBER BYPRODUCT FEEDS AND FORAGES

Author
item WAKKER, J - UNIVERSITY OF MINNESOTA
item Jung, Hans Joachim
item LINN, J - UNIVERSITY OF MINNESOTA

Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2006
Publication Date: 7/1/2006
Citation: Wakker, J., Jung, H.G., Linn, J.G. 2006. Evaluating in vitro cell wall polysaccharide digestibility of high-fiber byproduct feeds and forages [abstract]. Journal of Dairy Science. 89(Supplement 1):156-157.

Interpretive Summary:

Technical Abstract: The objective of this experiment was to examine the repeatability of in vitro cell wall polysaccharide digestibility (IVCWPD) analysis across time using 10 byproduct feeds and 12 forages. Ruminal contents were collected on a biweekly basis, over a 6-wk period, from a single lactating Holstein cow maintained on a total mixed ration. For every collection, feedstuffs were incubated in duplicate for 48 h at 39°C using the Ankom Daisy Oven system. The Uppsala dietary fiber method was used to analyze feeds and residues for cell wall polysaccharide constituents (neutral sugars and uronic acids). Week of rumen fluid collection significantly (P < 0.05) affected IVCWPD across feeds, with collection 3 having lower IVCWPD values than collections 1 and 2. Ranking of forages, but not byproduct feeds, by IVCWPD was affected (P < 0.05) by collection week. Average IVCWPD for whole cottonseed and wheat middlings were 33 and 56%, respectively, while the other 8 byproduct feeds ranged from 73-92%. For two corn silage samples (conventional and BMR), IVCWPD results from collections 1 and 2 were greater (P < 0.05) than for collection 3. Comparing the conventional and BMR corn silages, IVCWPD was different for collection 2 (72 vs. 64%) but not different for collections 1 (74 & 67%) and 3 (57 & 57%). For an alfalfa haylage sample, IVCWPD was greater (P < 0.05) for collection 2 than collection 3 (74 vs. 67%), with collection 1 being intermediate. Rankings of three alfalfa samples (1 haylage, 2 hays) for IVCWPD changed among rumen collections. The IVCWPD of the haylage was greater (P < 0.05) than of hay 2 for collection 1 (72 vs. 63%), greater than hays 1 and 2 for collection 2 (74 vs. 66 & 65%), but similar to hays 1 and 2 for collection 3 (67 vs. 63 & 62%). Repetitive rumen fluid collections under standardized conditions resulted in different IVCWPD results for forages but not byproduct feeds, agreeing with previous results for in vitro NDF digestibility.