Today and in the future, you will confront increased environmental pressures and regulations to control water- and air-quality concerns. Specific issues that face pork operations involve nutrient accumulation (especially phosphorus and nitrogen) in the soil, which could contaminate streams, lakes and ground water. Then, of course, there are gas and odor emissions that can cause nuisances and difficult neighbor relations. 

Since the pig is the point source of manure production, changing the diet or feeding program can significantly mitigate adverse impacts and help sustain the environment surrounding the operation. Implementing a feed-management plan is an important component of comprehensive nutrient-management plans, which address nutrient flow and control for the farm. 

Feed management encompasses all dietary aspects — selecting ingredients, formulation and delivering the ration to pigs. Through precision, it can reduce excess nutrient accumulation in soils, improve efficiency of nutrient utilization and reduce feed costs.

Depending on the base diet’s current composition, research has shown that diet modification may reduce nitrogen excretion by 20 percent to 40 percent, phosphorus excretion by 20 percent to 55 percent, sulfur excretion by 20 percent to 40 percent, ammonia emissions by 20 percent to 50 percent, hydrogen sulfide emissions by 20 percent to 50 percent and odor emissions by 20 percent to 40 percent.

What feed-management practices can effectively produce an environmentally friendly diet and feeding program? The answer starts by evaluating your current feeding program and diet formulations to see if you are reaching potential maximum production efficiency and minimizing nutrient excretions and odor impacts.

Here are some key questions to ask as you evaluate your current feed-management program.

Feed-management Practices

  • Are multiple diets (phases) formulated to meet nutrient requirements of the different ages of pigs?
  • If so, how many diets are used?
  • Are the pigs fed separately based upon sex?
  • Are feed-processing methods (particle size, pelleting) and quality-control procedures (mixing, calibrating scales) used in feed manufacturing to maximize nutrient availability and accuracy?
  • Do you routinely analyze diets for nutrient composition to check on formulations and nutrient delivery to pigs?
  • Do you analyze water for nutrients and consider that in diet formulations?
  • Are feeders adjusted and waterers checked daily to minimize feed and water spillage?  

Enhancing Nitrogen Utilization

  • Do you formulate and balance diets based on digestible-amino-acid ratios?
  • Are diets with reduced crude protein and added synthetic amino acids used to improve amino acid utilization and minimize nitrogen excretion?
  • When you use byproducts, are diet formulations adjusted to minimize excess nitrogen excretion?
  • Are safety margins minimized (5 percent) for amino acids?

Enhancing Phosphorus Utilization

  • Are diets formulated and balanced to meet the pigs’ available-phosphorus requirement? 
  • Is the diet formulated to meet the correct calcium-to-available-phosphorus ratio? 
  • Is phytase used with a reduction in inorganic phosphorus supplementation?
  • When byproducts are used, are diet formulations adjusted to minimize phosphorus excretion? 
  • Are safety margins minimized (5 percent) for phosphorus?

Production Aids/Enhancers

  • Do you use growth promoters (antibiotics, Paylean, copper sulfate, zinc, organic or inorganic acids) to improve nutrient utilization? 
  • Are specific enzymes (amylases, proteases, phytase) used to improve overall nutrient digestibility?
  • What is the herd-health (vaccination) program being used?

Consider contacting a nutrition consultant or feed-industry technical-service provider to help evaluate the feeding program for your operation. The goal is to evaluate whether diets can be improved to enhance nutrient efficiency to support profitable pork production in tandem with environmental sustainability. In many cases, you can reduce the import of nutrients on the farm and reduce feed costs without reducing pig performance.

Editor’s note: An evaluation checklist on this topic is available to producers and technical-service providers. For more information or to access the checklist, contact Brian Richert at or Alan Sutton at