Enhancing Dairy Profitability and Reducing Potential Water Pollution Through Lower Dairy Ration Phosphorus Levels

View the project final report

• 2004 annual report
• 2005 annual report

Commodities

• Animal Products: dairy

Practices

• Animal Production: feed formulation, manure management, mineral supplements
• Crop Production: nutrient cycling
• Education and Training: demonstration, on-farm/ranch research
• Production Systems: agroecosystems
• Sustainable Communities: sustainability measures

Pennsylvania nutrient management plans currently are most concerned with nitrogen loading of soils via animal manure applications. Limitations to how much can be applied are based on the risk for nitrogen loss into the groundwater. However, in the near future in PA, they will be changed to include phosphorus as a limiting nutrient. Increasing phosphorus levels in ground and surface runoff waters have become a major concern for area watersheds and especially the Chesapeake Bay. The most effective way to reduce manure phosphorus excretion is to feed less. Recent research has determined that dietary phosphorus levels for lactating dairy cows can be significantly reduced without negatively impacting milk production or reproductive performance. Presently, most dairy rations are being formulated with phosphorus levels higher than recommended by National Research Council (NRC 2001). Reducing phosphorus levels in Pennsylvania dairy rations to NRC recommendations can provide two benefits: reducing manure phosphorus excretion, thus reducing environmental concerns; and, most importantly, reducing dairy ration costs by $15.00 per cow per year with potential savings to Pennsylvania dairy producers of $9 million annually.

While producers are aware that manure phosphorus levels will decline when feed phosphorus levels are reduced, many are reluctant to reduce their phosphorus feeding for fear of reduced milk production or reproductive performance. Change in producer attitudes and practices are often more widely and rapidly accomplished when some from within their group adopt the change and document the desired outcome(s). This project seeks to accomplish reductions in manure phosphorus levels and improvements in farm income through a well-monitored multi-farm research/demonstration project of the new phosphorus feeding recommendations. Fourteen dairy producers from Southwestern Pennsylvania have agreed to cooperate in this project that will show that reducing phosphorus levels in the dairy ration to revised NRC recommendations will decrease manure phosphorus excretion and not adversely affect dairy cow performance. Environmental sustainability will be enhanced when bringing these farms into compliance for the new phosphorus-based nutrient management plans. Of even greater interest to the producers involved and to the dairy community at large will be the improvement in the economic sustainability of their individual farms through a reduction in the cost of feeding their cows without a reduction in gross income.