INFLUENCES OF PARTICLE SIZE OR BOILING TREATMENTS OF CEREALS AND SOYBEAN MEAL UPON IN-VITRO DIGESTIBILITY OF NUTRIENTS AND DIGESTION TRIALS WITH PIGS
1987 Volume 24 Issue 2 Pages 87-93
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1987 Volume 24 Issue 2 Pages 87-93
The influences of particle sizes of cereals and soybean meal upon the digestibility of nutrients were examined in this study by an in-vitro method using intestinal fluid of pigs and by digestion trials with growing pigs. The influences of boiling treatments of cereals upon the digestibility of nutrients were also studied with the in-vitro method.
Corn, rice, barley, wheat and commercial flaked soybean meal were ground in a mill without a screen, while naked barley was ground with a 3mm screen into beads size and then through a 1mm sieve into fine corpuscles. By this means, particles with geometrical mean (mm) diameters of 0.95, 1.61, 1.28, 0.95, 0.84, and 1.09 were produced for bead-size samples, respectively, and those of 0.36, 0.50, 0.34, 0.30, 0.49 and 0.38 for fine particle samples, respectively. Milo was ground and sieved through a 1mm screen (fine) into a mean particle size of 0.33mm. The beads-size cereals and fine milo particles were treated with boiling each in a beaker for 10 minutes (boiled).
The results revealed:
1) Grinding of cereals into finer sizes and their boiling treatment evidently improved the in-vitro digestibility of dry matter and crude protein (CP). The grade of the improvement was the highest of rice, whereas that of wheat or barley was relatively small. This was deemed attributable to the fact that rice is harder and more resistive than wheat or barley, by which digestive enzymes could less easily penetrate into the grain particles in rice.
2) Energy and CP digestibility of fine particles of rice in a digestion trial with pigs were found 5% and 10% higher than those of beads-size particles, respectively (P<0.05).
3) When measured at the terminal ileum and over the whole digestive tracts of pigs, there was no significant difference (P>0.05) among the varying particle sizes of soybean meals, whereas the digestibilities of dry matter, CP and non-protein nitrogen by the in-vitro digestion trial were clearly lower (P<0.05) in soybean flakes (unground) than soybean flakes in fine and beads-size particles.
