Small particle size makes a big difference

Posted on April 13, 2012 in Swine Performance
By Julie Salyer

Feed represents at least 75 percent of the total costs of today’s swine operations.  That means it’s not only important to know the composition of the ingredients and diets we are feeding, but also how these grains are processed. Grinding cereal grains is an effective way to improve feed utilization and decrease dry matter (DM), nitrogen (N) and phosphorus (P) excretion. Decreasing the particle size can improve digestibility of nutrients by increasing the surface area of the grains. This allows digestive enzymes in the pig’s system to utilize those nutrients. Digestibility of proteins, energy and other nutrients are generally improved with smaller particle size. Furthermore, particle size reduction can influence how uniformly feed is mixed, which therefore reduces the amount of segregation that occurs during handling and delivery to the animal. Generally, when particle size is reduced from 1,000 to 400 microns, swine feed conversion is improved by an average of 1.3 percent for every 100-micron reduction in particle size. Additionally, as particle size is reduced from 1,000 to 700 microns, DM and N excretions are reduced by 20 percent and 24 percent, respectively, in grow-finishing pigs.

Today, the recommended particle size is between 650 to 750 microns in mash diets.

Particle sizes below this recommended level can result in increased risk of ulcers, feed bridging and dust. However, complete swine diets with a particle size above the recommended levels have shown decreased feed conversion of 1.2 to 1.4 percent for every 100 microns above 700. When analyzing particle size, obtaining a representative sample is key. Fine and course ingredients may separate slightly during the shipping and handling process.  Therefore, you should collect several samples from different areas of the batch or from different feeders.  Then combine them for a composite sample. If you mix your feed on farm or are curious as to your grain or complete feed’s particle size, please contact your local Vita Plus consultant to receive details about how we can help you determine your current particle size.  

About the author:  Julie Salyer previously provided technical support for Vita Plus field and sales staff and conducted nursery research trials as a swine nutritionist.  Salyer received her bachelor’s degree at The Ohio State University and master’s degree in swine nutrition at Kansas State University.  She is originally from southwest Ohio, where she raised and showed livestock for the county 4-H fair. She was also a student worker at Ohio State’s swine farm and completed an internship in North Carolina for Murphy Brown LLC, which she says was instrumental to where she is today.  Salyer is active in church and enjoys hunting, kayaking, hiking and spending time with her husband, Brandon, and their two dogs.

Category: Feed quality and nutrition
Swine Performance