The effects of delayed planting can cause all manner of issues, be they logistical or financial, but what is not so well understood is that the quality of the silage produced may be another potential problem. The good news is producers can make adjustments during harvest and ensiling to maximize the quality and quantity of silage available to feed.
“The 2019 North American planting season was way out of the ordinary, with both late snow and constant rain in many areas, it made it impossible to plant corn as normal. With the changes to planting plans, requires us to make changes to the usual silage plans also,” explains Renato Schmidt, Ph.D., Technical Services – Forage, Lallemand Animal Nutrition. “If we’re prepared at harvest, we can still end up with high-quality, stable silage during feedout.”
There are three main concerns Dr. Schmidt warns producers of late planted corn to watch for in this year’s silage:
- Variability in forage maturities
- Increased mold growth
- Greater risk of clostridial fermentations
Addressing forage variability
Later planting means fewer growing degree units (GDUs). Many producers may have already changed their hybrid maturity at planting to help address this concern. But selecting a range of maturities can increase variation in moisture content at harvest, leading to variability in moisture levels and forage quality in the ensiling structure.
“The most important factor influencing forage quality is the maturity of the crop,” he says. “Harvesting forage with a high degree of variation in maturity levels means you’re going to see the same variations in the silage. This greatly affects the initial fermentation process, which sets producers up for pitfalls.”
Harvesting less mature corn also can increase the risk of seepage, late-planted Schmidt advises. Seepage is undesirable as it’s not only a loss of dry matter it’s a loss of the nutritional value of the silage. The first plants to be harvested are typically the wettest. When placed at the bottom of the storage structure, the weight of the silage on top will increase the likelihood of seepage.
To control the fermentation process, he recommends including a research-proven forage inoculant to stimulate a rapid, efficient fermentation. Inoculants that include lactic acid bacteria (LAB) such as Pediococcus pentosaceus 12455 accelerate the rate of pH drop. Quickly lowering the pH helps inhibit the growth of protein-degrading bacteria and reduce losses of the most highly digestible nutrients.
Preparing for mold challenges
The wet planting season could lead to increased opportunity for mold and mycotoxins. In particular, producers battling high insect pressure should be prepared for this challenge. Any physical damage to the corn plant — from insects, disease or weather — can lead to mold infestation and increase the potential for mycotoxin production.
In many cases, mycotoxins may be present even when there is no visible mold in the silage, causing unforeseen decreases in production, increases in herd health issues and lower fertility rates when fed.
To help minimize molding in the silage, so reducing the risk of mycotoxin contamination producers should use a proven silage inoculant containing Lactobacillus buchneri NCIMB 40788 which, reduces the growth of yeasts and molds in silage, ensuring the aerobic stability on opening.
Getting ahead of clostridial fermentations
Delayed planting also may result in harvesting at higher moisture levels, which can increase the risk of a clostridial fermentation. Any forage that is harvested below 30% dry matter (DM) is at risk of clostridial contamination. Clostridia are soil microorganisms naturally present on forages, but as they derived from the soil, the wetter the forage is harvested at, the more like high numbers of clostridia will be present in the silage. When allowed to grow in silage, they can produce butyric acid and a range of biogenic amines, resulting in a tell-tale fecal, or putrid, smell. This makes the silage virtually unpalatable and reduced dry matter intakes are normal when trying to feed such forage.
Ensuring the silage is packed at the correct density, use of a good covering, sealing the structure quickly and efficiently and using a research-proven forage inoculant for a fast initial ensiling fermentation all help reduce the chances of clostridia growth.