Project Number: 1902-13000-009-05
Project Type: Grant

Start Date: Dec 01, 2002
End Date: Nov 30, 2005

Objective:
The overall objective of this project is to develop feeding programs for lactating dairy cows using common ration formulations that can result in a minimum amount of manure P. We expect a 30-35% reduction in manure P excretion compared to current feeding practices. Previous work of some of the principal investigators of this project demonstrated that a reduction of manure P excretion is possible. The proposed project will expand this research to include the influence of several common feeding practices on manure P excretion. It will also address the mechanism of fecal P excretion through which a reduction in manure P can be obtained by manipulating feeding practices. The developed feeding programs will be evaluated based on animal performance, manure P excretion, soil P loss when applied to cropland, and overall farm performance and economics. The principal investigators of this project have worked in the area of nutrient management from the perspectives of animal nutrition, soil P utilization, watershed movement, and farming systems. This project will engage multidisciplinary expertise in a collaborative effort to develop dairy feeding strategies that help dairy producers minimize the environmental consequences of their operation while sustaining their animal husbandry and farm profitability. The specific objectives of the Penn State Cooperator is to (1) determine the effect of alternative dairy feeding practices on the amount and chemical form of P excreted in manure.

Approach:
Controlled feeding studies will be conducted at Penn State's Dairy Cattle Research and Education Center. Dietary treatments will include: low P-low forage, low P-high forage, high P-low forage, and high P-high forage. The dietary P levels will be 0.38 and 0.48% and the forage levels will be 48 and 58% of the diet on a dry-matter basis. The sources of forage in all treatments will be alfalfa silage, alfalfa hay, and corn silage. Corn will be the major concentrate source of the diets and will be steam-flaked to enhance rumen fermentability. Thirty-two early to mid lactation cows will be individually fed for 15 weeks. Feed intake and milk yield will be recorded daily. Fecal and urinary samples will be analyzed for P content. Chromic oxide will be used as an external marker to quantify fecal P excretion.

Project Team

Sharpley, Andrew Zhiguo Wu - Assistant Professor, Ruminant Nutrition 814-863-0948

Project Annual Reports

FY 2003

Related National Programs

Water Quality & Management (201)   Manure and Byproduct Utilization (206)