Inoculant strategies for corn silage, high moisture corn and snaplage
The majority of dry matter (DM) losses occur during the front end ensiling process (as the pH drops) and during the back end (after exposure to oxygen when lactate-assimilating spoilage yeasts flourish). Spoilage yeasts are especially prevalent in feeds rich in starch, such as corn silage, high moisture corn (HMC) and snaplage.
The main differences between corn silage, HMC and snaplage are the DM at harvest and the origin of the feed:
- Corn silage, made from the entire corn plant, is typically ensiled at a DM content of 32 to 35 percent.
- HMC, made from corn kernels, is typically ensiled at 68 to 72 percent DM.
- Snaplage is made from of the entire ear (husk, cob, grain and part of the shank). It is considered middle ground between corn silage and HMC and the ideal DM content for harvest, 58 to 64 percent, is no exception.
Inoculation strategies for these three feeds differ due to the moisture content, the time of the year of ensiling, and the chemical characteristics of the crops.
When producing corn silage, the main concerns are equally for the initial pH drop and the preservation of aerobic stability upon opening. Therefore, the ideal inoculant would be a combination inoculant that contains an upfront fermenter (such as Pediococcus pentosaceus or Lactobacillus plantarum MTD/1) and bacteria proven to preserve aerobic stability (L. buchneri).
The strategy for treating HMC differs as preventing spoilage is the main concern. To prevent spoilage, HMC should be treated with L. buchneri. Typically, the pH drop in HMC occurs quickly enough that an upfront fermenter is not necessary, unless the HMC is drier (closer to 25 percent moisture). As HMC silage dries during autumn’s cooler temperatures, the numbers of naturally occurring fermentation bacteria decrease.
Improving fermentation in drier HMC, such as with the use of a combination inoculant, may result in improvements in DM recovery, starch digestibility, aerobic stability, and animal performance. In all cases, HMC should be ensiled with a minimum of 25 percent moisture. Because the moisture content of HMC is lower than that of corn silage, the crop ferments slower. Thus, HMC requires more bacterial numbers and a typical dose of inoculant for HMC is 1.5 times the typical dose of inoculant for corn silage.
Inoculation of snaplage has always been a gray area, which makes sense for a crop with a chemical composition between HMC and corn silage. Current recommendations are to treat snaplage with similar bacterial numbers as HMC. That said, it’s not uncommon to hear anecdotal reports of producers who successfully treated snaplage with 1.25 times the typical dose of inoculant for corn silage.
Snaplage typically faces the same aerobic stability challenges as HMC and corn silage, but it also does not pack as densely as HMC. Therefore, the upfront fermentation may be compromised and a combination inoculant is recommended for snaplage.
Every crop requires consideration of the unique challenges and how to compensate for them. If you need assistance in choosing inoculants, appropriate dosages, or methods of application, contact a Vita Plus consultant or dealer near you.