Ask the Silage Dr: Improve feedout stability
Q. How can I improve my feedout stability next year?
A. Even crops harvested at the optimal maturity, moisture content and chop length can be susceptible to heating and mold growth. Silage can appear to ferment well and then heat and spoil during feedout.
Yeasts that occur naturally in all forage and high moisture grain crops are the main cause of aerobic instability and, while they grow best on soluble sugars, they can also grow on the lactic acid produced during the initial ensiling fermentation and pH drop.
When crops with high natural yeast populations are ensiled, yeasts grow until the oxygen is consumed and will produce ethanol from residual glucose by anaerobic fermentation. When fermentatble sugars are exhausted, the yeasts become dormant. When silage is opened at feedout, it is once again exposed to air (oxygen) that allows yeasts that survived the ensiling process to grow. This occurs within a few hours after exposure to air.
Issues due to this secondary growth of yeasts are compounded as the yeasts metabolize lactic acid, which can result in lost dry matter (DM), total digestible nutrients (TDN) and generation of heat. As lactic acid is consumed and the silage pH rises, molds can begin to grow and cause further digestibility and palatability problems.
Good harvest and management practices that reduce exposure to air are critical: fill the silo or bunker quickly, pack adequately, cover well and seal it tightly. All these practices minimize oxygen exposure, which improves stability.
In addition, an inoculant containing Lactobacillus buchneri 40788 at an effective dose can help address stability challenges. High dose rate L. buchneri 40788 (400,000 CFU/g for silage, 600,000 CFU/g for HMC) has been reviewed by the FDA and allowed to claim efficacy in preventing heating and the growth of yeasts and molds in silages and HMC.
If your stability concerns primarily occur during feedout, make sure feedout rates are adequate and that animals are consuming ensiled feeds within a few hours after removal. This is of particular concern during warm weather.
I hope this information helps you improve feedout stability.
Sincerely,
The Silage Dr.
Question about silage management? Ask the Silage Dr. on Twitter, Facebook or visit www.qualitysilage.com.
