4 Factors Negatively Contributing to Feed Fermentation

May 20, 2021

Hot summer days have finally made their appearance and with that comes potential for heat stress resulting in decreased milk production in lactating dairy cows, lower feed intakes and lower pregnancy rates. Decreased feed intake can be caused by increased fermentation in our feedstuffs causing growth of molds and yeasts resulting in decreased palatability of TMR once it hits the feed bunk.

There are several factors that contribute to feed fermentation which negatively impact the quality of feed going into the bunk. 

1. Temperature

  • Fermentation begins at 45 degrees Fahrenheit. 
  • Every 10 degrees above ambient temperature of TMR (70 degrees) results in 3/4 lbs of milk production loss. 
  • A rise from 80 to 120 degrees under a high heat/humidity combination is not uncommon. Under these stressed conditions, up to 3.2 lbs of milk production can be lost due to decreased DMI and reduced energy of feed consumed. 

2. Moisture

  • Feedstuffs containing 14-15% or more of moisture are more susceptible. 
  • Secondary fermenation is accelerated when relative humidity is 70% or greater. 

3. Oxygen

  • Exposure to air during mixing, scooping, dumping or pushing at the feed bunk allows oxygen into the mix resulting in yeasts being re-energized. Yeast are lactic acid consumers which creates unstable and unpalatable feed. When lactic acid is consumed, the silage pH rises causing mold to grow very rapidly which results in spoilage. 

4. Energy 

  • Ground or cracked grains/starch/sugars make nutrients available for secondary fermenation. 
  • Added fats also enhance fermentation and can cause potential rancidity on hot days. 

Reach out to your UC Feed Sales Specialist to see how a TMR stabilizer could help.



David Cramer