To the naked eye, size differ-ences between grain particles may seem insignificant, but it can make a big difference when feeding pigs, say Kansas State University researchers.

Drawing from previous trials, the researchers found that finely grinding grain (to about 700 microns by industry standards) and adding fat improves the pig's performance and a producer’s profitability.

But both fine grinding and adding fat can create problems with feed “bridging” in feeders and bins. “It’s a feed management issue,” says graduate student Crystal Groesbeck, who has led the trials. “When feed gets caught up in bulk bins and doesn’t flow, pigs don’t eat. We wanted to look at how the type of feed mill used to grind corn affects its ability to flow.”

Groesbeck’s work shows that grain ground with a roller mill is more uniform than grain ground with a hammer mill. As a result, roller-milled ground feed flows better than does hammer-milled feed.

“The advantage in flow-ability is so great that when adding 6 percent fat to roller-milled corn, the flow-ability of the feed was similar to the hammer-milled corn with no fat added,” she notes.

That’s important, Groesbeck adds, “because if you improve your grind, you improve your profits.” Each producer will need to determine the right combination of particle size and added fat for his specific feeding program.

Groesbeck’s research has looked only at ground corn, but other trials are planned.