Ask the Silage Doctor

Read below for posted questions and answers from the Silage Doctor.
To submit your own question to the Silage Doctor, please click here.
Please visit again soon for new questions and answers.

Question:
"I made alfalfa silage with inoculant and now we note it’s clearly less brown than the silage without inoculant treatment. Could you explain this color difference?”
-Hector

Answer:
Dear Hector,

The brown color is caused by non-enzymatic browning (the Maillard reaction) due to a reaction between sugars and proteins in the crop. As a chemical reaction, the rate of the reaction is increased by heating (for example, the browning on the top surface of a loaf of bread when it is baked), so the untreated silage has more brown color because it has heated significantly during the initial ensiling fermentation. Using a good, proven inoculant will give a faster, more efficient fermentation, with less heat generated and the ensiled alfalfa will be green, as it should be.

Best regards,
The Silage Doctor

Question:
"Cereal silage is being harvested when the temperature ranged from -5 to 10 degrees C. at 70% plus moisture. What concerns would you have and how would you deal with them?”
-Dave

Answer:
Dear Dave,

Obviously this does raise some issues.  As you know, as the temperature decreases, the rate of biological processes decreases, which includes the growth and fermentation rates of the bacteria required to ensile the crop.  This is coupled with the fact that the cereal silage crop is usually low in natural lactic bacteria, as it is mature material. Confoundingly, this also means that it is more likely to be carrying a high level of yeasts and molds, leading to potential issues with aerobic stability.  Thus it is important that the material be treated with something that is going to minimize yeast and mold growth in the silage, and something that will get going at the low ambient temperatures.  If this is a microbial, then it itself will generate heat as it grows, and so in large silage structures filled in the dead of winter, typically we still see the silage reaching temperatures in the 20’s (Celsius).  Check to see that the microbial has been tested and or proven in commercial use in these wintery conditions.

Preventing yeast and mold growth basically boils down to one of two options: Lactobacillus buchneri-based inoculants or the application of a propionic-acid based chemical additive at the rate recommended and validated by the manufacturer.  Of the LB-based inoculants, only those containing a high dose rate (400,000 CFU/ g silage; 600,000 CFU/g HMC) of the strain L. buchneri 40788 have been reviewed by the US FDA and allowed to claim improved aerobic stability.

The final issue then is preventing the product from freezing in the tank while during chopping.  This can be at least partially obviated by using an applicator with an insulated reservoir (e.g. the DE 1000 from Dohrmann).  Additionally, with the Biotal brand inoculants we have tested the inclusion of 10% anti-freeze in with the inoculant in the applicator reservoir and have found this effective and to have no negative effect on the viability of the Biotal products.