Effect of grinding particle size of pig feed raw materials on nutritional value

Research from Kansas State University shows that reducing the crushing particle size of feed ingredients can improve feed digestibility in weaned piglets and
 improve production performance throughout the finishing period. This study is mainly to observe the impact of hammer crushing or roller crushing method
on the nutritional value of corn or sorghum. The results show that reducing the crushing particle size can improve the digestibility of corn or sorghum dry matter,
energy and protein in weaned piglets.

Gary E Allee's research believes that when the feed particle size increases, the feed intake will also increase, and the feed micron powder particles processed
by the hammer mill can minimize the feed intake. A1lee reports that reducing the crushing particle size of corn or sorghum will improve the feed conversion rate
and digestibility of dry matter, protein and energy. However, A1lee has not conducted relevant research on the ideal crushing particle size of corn or sorghum.
This crushing particle size means the greatest economic benefits and the best production efficiency.

Regarding the reasons for the above research results, Allee explained that reducing the crushing particle size can increase the contact area of digestive enzymes
on the feed particles. When the feed is crushed by hammer blowing, flattening, roller crushing or hammer crushing, When any type of material is processed,
its surface area increases geometrically.

Allee also pointed out that the impact of feed crushing particle size on animal production performance is also closely related to the type of feed and the growth stage
 of the animal. He gave an example, unlike piglets, fattening pigs (54kg to slaughter) chew the feed less finely, thus leading to a decrease in the utilization rate of
the whole grain feed. The research results also show that for pigs at any growth stage, feed processed by hammer crushing or roller crushing methods can
 improve their production performance.

In the study, both corn and sorghum were processed using hammer mills equipped with 3.18 mm (fine crushing) or 6.35 mm (coarse crushing) blades.
The particle size of the feed processed by the hammer-type coarse crushing and the double-roller fine crushing is similar,
but the feed processed by the hammer crusher will produce a large number of particles (particle size <0.145 mm).
Allee believes that particulates can reduce the palatability of feeds. Research shows that grinding particle size, raw material type and grinding method have no
significant impact on the average daily gain of pigs.

The study also found that pigs' feed intake of diet processed by the crushing method was greater than that of the hammer crushing method. In this regard,
Allee explained that the roller crushing processing method reduces the amount of particles produced, so the feed produced by this processing method is more
attractive to weaned piglets. In addition, Allee believes that regardless of the type of raw material, reducing the crushing particle size can increase the feed conversion
rate and improve feed digestibility. The reason is that the increased particle surface area increases the contact area and mixing degree of the feed and digestive
enzymes. .

There is currently sufficient evidence to prove that crushing particle size is closely related to porcine gastric ulcers. Data cited by Allee indicate that reducing the
particle size of raw materials increases the incidence of gastric ulcers and other stomach problems.