Finer Ground Corn More Digestible

Finer Ground Corn More Digestible
Hans Stein, Swine Nutritionist - University of Illinois

An animal nutritionist at the University of Illinois has quantified the importance of particle size in ground feed for hogs.

Grinding corn to finer particle sizes can increase its feed efficiency by up to five percent says Hans Stein.
They don’t gain any more, but they eat less to gain the same. Pigs adjust their energy intake. It means there is more available energy in corn when it is ground finer. The pigs eat less, the feed conversion is improved, and it takes fewer pounds of feed to produce a market weight hog.
Stein is a swine nutritionist at the University of Illinois. He investigated the affect of different particle sizes of ground corn when fed to pigs. The corn was ground to 800, 600, 400, and 300 microns.
We discovered amino acid and phosphorous digestibility does not change with particle size. Pigs are very efficient in digesting those nutrients, but when it came to starch we found a linear increase in digestibility as we reduced the particle size of corn. The highest digestibility was with the lowest particle size of corn.
This is because more starch is digested in the pig’s small intestine, causing more glucose to be absorbed and therefore increasing the amount of available energy.
The energy in the corn grain increased as we reduced particle size. A pig will get more energy out of one pound of corn if it is ground to 300 microns instead of 800 microns.
This is were the savings come in to play. The feed conversion rate improves by about one-point-two percent for every 100 micron reduction in particle size, saving seven pounds of corn to finish a pig.
Or producers wanting to formulate diets to a prescribed amount of energy could reduce fat in the ration. Fat is usually used to add more energy, but corn ground to a smaller particle size could replace it. The pigs should perform the same using corn ground to a smaller particle size.
There are a couple of negatives to the smaller grind. The feed doesn’t flow nearly so well and there is an increased risk of stomach ulcers. The ILLINOIS nutritionist says hog producers should try smaller grinds over time, ratcheting down a hundred microns every couple of months. Rations with higher fiber contents will be most successful at the lower particle sizes.