Flinty vs. Floury Hybrid Starch Digestibilities Highly Dependent on Maturity and Processing Method
By Bill Seglar
In a beef trial from Nebraska, a "flinty" or vitreous hybrid and a floury hybrid were fed to steers in a feedlot trial (291 steers; 191 days) as high moisture corn (HMC) or as dry rolled corn. Feed efficiencies were equal for the two hybrids when fed as high moisture corn. However, when fed dry rolled, gains favored the floury type as listed in the table below. Starch digestibility was lower for the flinty hybrid and was not altered by processing.
|HMC||Dry Rolled||HMC||Dry Rolled|
|Average Daily Gain, lbs.||3.7a||3.6a||3.6a||3.3b|
|Dry Matter Intake/Day, lbs.||19.6||20.0||19.4||19.6|
|Feed/Lb Gain Ratio||5.36a||5.55a||5.37a||5.86b|
|Starch Digestion, %||98.1a||96.7||95.3||95.6|
|NE-g (Mcal/lb) (from performance)||0.74||0.72||0.74||0.68|
a,b = means rows with different letters are significantly different (P < 0.05)
The study suggests that the kernel texture starch differences between floury and flinty genetics is a function of maturity. The method of processing largely impacts how cattle will respond to feeding these hybrids. No significant differences exist between floury and flinty HMC, but an advantage is possible when feeding floury dry rolled corn compared to flinty dry rolled corn. Pioneer nutritionists speculate that fine grinding of flinty corn grain may produce animal performance results similar to feeding course-ground floury grain. More research is needed in this area.
The digestibility and starch utilization that cattle might derive from corn silage can be compared to the HMC results in this study. The results suggest that HMC utilization will be similar to what one would expect with the corn grain in corn silage. Therefore feeding corn silage that originates from floury or flinty genetics has little impact on cattle performance.
Macken, C.N., Erickson, G.E., Milton, C.T., Klopfenstein, T.J., Block, H.C., Beck, J.F. 2003. Effects of Starch Endosperm Type and Corn Processing Method on Feedlot Performance and Nutrient Digestibility of High-Grain Diets. U. of NE, Lincoln. Abstracts American Assn of Animal Science, p. 86; Abst 345. March 17-19, 2003.