Effect of particle size of corn grains on the release of nutrients and in sacco degradability

The relative proportion of albumin, globulin, prolamin and glutelin in corn grain was 10.44, 12.56, 31.65 and 45.35%, respectively. The prolamins and glutelins were least degraded in the rumen. Corn grains were crushed and sieved through screens of four different pore sizes (1.0, 1.5, 2.0 and 2.5 mm). The average particle size increased (P<0.05) whereas the surface area decreased linearly (P<0.05) with the increase in pore size of screen. The crushed corn grains in triplicate were soaked with water in 1:1.25, 1:1.50, 1:1.75 and 1:2.00 ratio for 0, 2, 4, 6, 8, 10 and 12 h at room temperature. With the increase in the particle size, irrespective of moisture level or soaking period, the release of water soluble carbohydrate (WSC) and protein (WSP) decreased (P<0.05) and water holding capacity (WHC) increased (P<0.05) linearly. The WSC, WSP and WHC increased (P<0.05) with the increase in the moisture level, irrespective of particle size of crushed grains or period of soaking. The release of WSC and WSP increased (P<0.05) up to 4 h soaking and WHC up to 8 h soaking. The digestion kinetic parameters revealed that the potentially degradable and undegradable fractions declined linearly with reduction in particle size thereby leading to linear increase in the effective DM degradability with the reduction in particle size of corn grains. It was concluded that corn grains crushed and sieved through 1–1.5 mm screen, soaked with water in 1:2 ratio for 4–8 h was sufficient for softening the hard texture, release of water soluble nutrients and their effecient utilization.