by Warren Rusche, South Dakota State University

Any time wet weather causes harvest delays, the risk of grain sprouting preharvest increases. This issue occurs more frequently with small grain compared to corn or milo, but even those row crops are susceptible under the right conditions.

In the case of corn, certain fungal diseases affect the balance of two plant hormones, abscisic acid and gibberellic acid, which influence whether the kernel will become dormant or begin germination.

Germination causes starch stored in the kernel to be converted to sugars along with heat, carbon dioxide and water. Because of these changes, sprouted grains are generally unsuitable for milling, brewing and food industries. In addition, because germination reduces starch and conditions favoring sprouting and mycotoxin can be related, ethanol processors may be less willing to purchase affected corn.

In most cases, we can feed sprouted grain to cattle or sheep with nearly the same results that we would expect with normal grain. Researchers from Idaho compared normal and sprouted wheat and found gains and feed efficiencies in yearling steers did not differ based on sprout damage.

Similarly, when researchers in Kansas fed sprouted milo to feedlot steers, they observed slightly improved performance. These results, plus other published research support the conclusion that sprouted grain can be used in ruminant diets. Sprouted grains should be processed similarly to normal feeds, especially for small grains, which require either rolling or grinding to optimize digestibility and energy value.

What about mold or mycotoxins?

The same environmental conditions that trigger premature germination are associated with mold growth. For this reason, feeders need to carefully evaluate the extent of mold damage and consider testing for mycotoxins.

Cattle are less sensitive to mycotoxins than are sheep. There is also less risk with growing or finishing livestock compared to breeding animals, especially those that are pregnant. Strategically allocating feedstuffs to less sensitive livestock classes reduces risk while still salvaging value from the crop.

Harvest and storage considerations

Harvesting sprouted crops as soon as practical will limit the extent of damage and capture the most feed value. Storage strategies should focus on preserving value and preventing further dry-matter losses or mold contamination. Storing as high-moisture feeds would work, assuming the grain is at the correct moisture content and that high-moisture storage facilities are available.