Project Number: 3655-31000-018-03
Project Type: Trust

Start Date: Dec 15, 2000
End Date: Dec 31, 2004

Objective:
1. Determine the precision and agreement among 5 methods currently used to measure particle size in feeds. 2. Develop a system to determine physically effective neutral detergent fiber (peNDF) directly, using feed particle size. 3. Evaluate the efficacy of directly measured peNDF in meeting effective fiber requirements. 4. Determine interactions between Rumensin supplementation and peNDF concentration in the rations of lactating cows.

Approach:
Particle size of 30 hays, silages, rations, and feeds will be measured using the Penn State, wire mesh, American Society of Agricultural Engineers, vertical shaker and horizontal shaker methods. Precision of and agreement among methods will be determined. Efficacy of particle sizing methods for assessing peNDF will be evaluated by comparing particle size to tabular physical effectiveness factors and to fecal particle size distributions. Twelve lactating cows will be used to evaluate directly measured peNDF and determine the interactions between Rumensin and peNDF. Positive (23% peNDF and 60% forage) and negative (16% peNDF and 40% forage) control diets will be fed with and without Rumensin. The negative control diet with Rumensin will be supplemented with coarsely chopped straw or finely chopped alfalfa and corn silages to meet a minimum peNDF (22%) requirement. Measurements will include intakes of dry matter, NDF, and peNDF, and milk production and composition, and chewing activity.

Project Team

Mertens, David

Project Annual Reports

FY 2003   FY 2002   FY 2001

Related National Programs

Food Animal Production (101)