KSU says a 10-minute sieving time for feed pellet analysis is sufficient.
MANHATTAN, KANSAS, U.S. – New research by Kansas State University (KSU) shows commercial laboratories and livestock producers who run their own analyses on grain-particle size can reduce the time it takes to check a sample from 15 minutes down to 10 minutes and get the same result by making a couple of changes to the process.


To help with that process and cut down on expenses, the KSU researchers have outlined new recommendations for evaluating particle size.

“Grain accounts for a major component and cost in livestock diets,” said Charles Stark, associate professor in KSU’s Department of Grain Science and Industry.  The particle size of ground grain influences feed digestibility, feed efficiency, how well it mixes and how well it can be pelleted, so periodic particle-size evaluation is a necessary part of quality feed manufacturing.

For that reason, Stark and other KSU researchers and specialists recommend routine evaluation of the grinding process, whether through a hammer mill or roller mill to determine grain-particle size.

The cost of the equipment needed to run such analyses, however, typically runs $5,000 or more, he said, so most producers in Kansas send grain samples to commercial laboratories or the KSU Swine Lab for analysis.

Stark outlined new recommendations based on the research at the recent KSU Swine Day 2016 in Manhattan and in a new publication,” Evaluating Particle Size of Feedstuffs.”

The new recommendations for running feed through a sieve to determine particle size are to use sieve shakers; sieve agitators, such as rubber balls or brushes; a dispersing or flow agent such as silicon dioxide; and to use 10 minutes of sieving time.

This is different than what many labs are doing, Stark said, and it’s been adopted by the KSU Swine Lab. Until now, the analysis process typically included a 10- or 15-minute sieving time and often hasn’t incorporated sieve agitators or flow agents, but KSU’s work indicates that a 10-minute sieving time is sufficient if labs incorporate sieve agitators and a dispersing agent.

Without sieve agitators or a dispersing agent, buildup occurs on the sieves, which keeps grain particles from moving through, making the results less accurate than they should be.

The research results showed that 10-minute cycles and 15-minute cycles with the sieve agitators are basically identical, so Stark and other KSU specialists believe 10 minutes with the agitators and flow agent will give the result needed, he said.

“With all of the different methods used in the industry and commercial labs, it’s important to know how your lab is conducting the analysis and that adding the agitators and flow agent will significantly reduce the particle result,” Stark said.

More information is available from the KSU publication online.