A new test could help cattle producers reduce a phenomenum called new corn silage slump. Calibrate® Technologies has a new testing system that keep cows’ production on track shows by showing producers corn silage starch and fiber digestibility factors.
Corn silage is highly variable, says Dr. David Weakley, director of dairy forage research for Calibrate® Technologies. Crude starch, rumen degradable starch, neutral detergent fiber (NDF) and NDF digestibility can vary from year to year, from field to field and hybrid to hybrid.
Results from a sampling program in Texas show just how variable things can be. “We tested 300 fresh cut corn silage samples from a handful of Texas producers,” says Dr. Weakley. “Samples were taken from 12 different corn silage hybrids. Results showed crude starch varied from 22.8 percent to 46.1 percent. NDF ranged from 30 percent to 67.6 percent.” Calibrate’s rapid NIR test was used to determine digestibility values for those 300 corn silage samples.
The results in Texas are similar to what is seen every year across the country in corn silage samples. Corn silage contains a lot of variation; not only at harvest, but it continues to change during ensiling until fed to the cows, explains Dr. Weakley. The longer corn silage is ensiled the more digestible the starch becomes. “That means by the time spring rolls around, if you haven’t adjusted the ration to account for the increase in starch availability in the corn silage, cow performance can suffer,” he says. “Generally, when starch availability climbs above optimal levels in the diet; the butterfat content of milk drops.”
Calibrate officials suggest testing for rumen digestibility of starch and fiber every two weeks. NDF digestibility provides insight into rumen fill, how quickly feedstuffs pass through the rumen and dry matter intake; all of which are helpful information to minimize variation in the cows’ diet and subsequent performance.