by Jeff Knott

Significant strides have been made over the past 40 years to improve and reduce the environmental impact of swine production. The environmental footprint of swine production is at an all-time low and through a combination of sound science and dedicated pork producers, the future impact will be further reduced. This article will highlight the past, present, and future of many of the major factors which have positively contributed to reducing the environmental impact of swine production. Although there are many more, this article will focus on swine nutrition advancements in technology and precision formulation.

Precision formulation has allowed nutritionists to better match nutrients provided in feed ingredients to the requirements of swine. Through an improved understanding of the pig’s nutritional requirements, it has been determined that pigs do not have a true requirement for crude protein, but rather for their specific building blocks, amino acids, in certain proportions.

This understanding, in conjunction with better analytical methods, has allowed swine nutrition to evolve from formulating diets on a crude protein basis to a total amino acid basis and to today where it is standard practice to formulate on a digestible amino acid basis. By formulating on a digestible amino acid basis, the crude protein of swine diets has been dramatically reduced while the needs of the pig have still been met (Figure 1).

The way energy is formulated into the diet has become more precise as well. Nutritionists now better understand ingredient digestibility to the point where they can better predict how feed energy is driven towards production and growth, as well as what components are excreted in the feces and urine or given off as heat. Not long ago, nutritionists formulated on a digestible energy basis. Through a better understanding of energy utilization, formulation transitioned to metabolizable energy basis and was refined further to the point where most formulation today is done based upon net energy. These precision formulation methods have provided for better productivity of swine, while reducing feed costs. In the future, it is likely nutritionists will be formulating diets to not only the nutritional requirements of the pig itself, but to its gut microbiome as well. Manipulating gene regulation through nutritional metabolomics may also become a reality.

Feeding the gut microbiome may include feeding different fibers or functional ingredients to provide nutrients to the diverse microbiota found within the gastrointestinal tract, promoting gut and overall pig health. Providing nutrients preferred by certain types of bacteria may also be used to improve total diet digestibility, further enhancing feed efficiency.

Nutritional metabolomics could involve feeding biologically active peptides that up or down regulate genes that are important for growth or feed efficiency. We have only exposed the tip of the iceberg when it comes to the potential applications of these technologies. Scientists are working to further refine precision formulation for enhanced performance and lower cost of production.

In the future, it is likely nutritionists will be formulating diets to not only the nutritional requirements of the pig itself, but to its gut microbiome as well.

Twenty years ago, the rule of thumb was to add three pounds of crystalline lysine and 97 pounds of corn to replace 100 pounds of soybean meal. Today, most swine diets incorporate from four to six crystalline amino acids (lysine, methionine, threonine, tryptophan, isoleucine and valine) to reduce diet cost and more closely meet the pig’s requirement with less excess crude protein.

For instance, a properly balanced early grower diet with three pounds of crystalline lysine would have contained over 22% crude protein. Through the incorporation of these additional crystalline amino acids, a diet with the same digestible lysine will be only 18% crude protein and include over 300 pounds less soybean meal (Figure 1). The pig’s performance will be the same or better with substantially lower feed cost and less excreted nitrogen. Will nutritionists get to a point where crystalline amino acids can 100% replace soybean meal or other protein sources?

The enzyme phytase became commercially available in the late 1990s and changed how nutritionists formulate diets to meet the pig’s phosphorus requirement. Most phosphorus in cereal grains is in an indigestible form called phytic acid. Phytase allows this previously bound phosphorus to be available to the pig. This greatly reduces the amount of inorganic phosphorus that needs to be included in the diet to meet the pig’s requirement and subsequently reduces phosphorus excretion in manure. Enzymes hold great promise going into the future.

The development of protease (degrades protein), cellulase (cellulose), and other enzymes will help nutritionists get more out of the ingredients they feed pigs by enhancing nutrient digestibility.

Science and technology will continue to allow swine nutritionists to better match the nutrient requirements of pigs with better precision and lower cost. Further advancements will continue to reduce the environmental footprint of swine production. The goal of all nutritionists is to maximize the nutrients utilized for pork production while minimizing those that end up in the pit. Will there be a day when swine production has a net zero environmental impact? Time and science will tell…

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JEFF KNOTT, PH.D.
Dr. Knott has over 15 years industry experience and is a specialist in providing technical nutritional support to swine producers around the world. Jeff has a B.S. in Animal Science from North Dakota State University, M.S. and Ph.D. from the University of Minnesota in Animal Science (Swine Nutrition). He has vast domestic and international swine nutrition and business experience. Jeff spent 10 years with a national nutrition company before founding IDEAL Animal Nutrition.

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