Maureen Hanson
December 16, 2021
Corn silage, the milk-making staple of most dairy operations, can vary considerably in yield, feed value, and quality from year to year.
The 2021 crop year was no exception. Drought throughout most of the country, severe weather, and even flooding in parts of the Northeast made the annual adventure of corn silage production an interesting one.
The New York and Vermont Corn Silage Hybrid Evaluation Program is an annual, collaborative effort between Cornell University and the University of Vermont. The program samples corn silage varieties in trial plots across a variety of New York and Vermont locations, harvests the corn silage according to maturity, and calculates performance results. This year, 60 hybrids from 12 seed brands were evaluated across 5 locations. The varieties were evaluated for yield, moisture at harvest, quality characteristics, milk/ton, and calculated milk yields.
The highly detailed 2021 report shares not just this data, but compares it to results over the past five years.
The Cornell-Vermont research team concluded that, overall, average to above-average growing degree days accumulation, coupled with significant mid-season rainfall, resulted in robust yields and high starch content, but lower fiber digestibility, especially compared to 2020. They said changes will need to be made in feeding programs as farms transition from the 2020 to 2021 crop.
Regarding annual concerns about mycotoxin contamination in corn silage, Alltech, Inc. performs an annual, nationwide assessment of mycotoxins as corn silage is harvested.
The company’s internal mycotoxin specialist, Dr. Max Hawkins, reported in a recent webinar that the 2021 crop shows signs of plant health damaged by drought stress in the West through the Corn Belt; crop damage due to severe weather; and insect damage due to the dry spring.
Alltech evaluated 227 samples of freshly harvested corn silage from across the country, starting August 20 and ending November 1. Their accredited system of analysis checks for 54 individual mycotoxins, including mass mycotoxin groups like the deoxynivalenol (DON)-3-Glucose family; specific mycotoxins of concern like fusaric acid; and storage myctoxins like aspergillus. This year, the average number of mycotoxins detected per sample was 5.6, which Hawkins said is about average compared to other years. Nearly all (96.5%) samples contained more than one mycotoxin.
The organisms of highest incidence were fusaric acid (99.12%); Type B trichothecenes (91.63%); fumonisis (62.56%); and emerging mycotoxins (56.39%).
Type B trichothecenes was the runaway winner – and not it a good way – when it came to average mycotoxin concentration at 2,488.2 ppb, which was about 2.5 times higher than its average concentration in 2020. The next closest average concentration was fusaric acid at 382.1 ppb.
Hawkins is especially concerned about Type B trichothecenes – which is a member of the DON family of organisms – because “unfortunately, we don’t feed averages,” he said. The maximum concentration of the organism detected in a single sample was 22,537 ppb, or 22+ ppm, which would be a hefty and damaging dose if fed in an individual batch of silage.
“Everyone needs to test their own silage,” he advised. As new batches are opened, he said oxygen exposure, face management, pocketing, and feed-out rates can influence growth of storage mycotoxins. “Don’t go to sleep on zearalenone and penicillium as the feeding season goes on,” he cautioned. “Test and test regularly.”
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