Sampling Silage
Accurate forage analysis is essential for balancing rations and maintaining consistent animal performance. Silage that appears similar from day to day may still differ in:
  • Moisture
  • Protein solubility
  • Fermentation characteristics
  • Nutrient concentration due to hybrid, field, soil, or weather variability
These differences can significantly affect ration accuracy and livestock output. Regular sampling allows producers to adjust rations efficiently and minimize unexpected performance drops.
 
How Often Should Silage Be Sampled?
Silage should be sampled:
  • By each field and hybrid
  • Frequently throughout the feeding period
  • More often when conditions suggest variation, such as:
    • Changing moisture
    • Visible heating
    • Shrink or seepage
    • Weather shifts affecting feedout
For best results, check dry matter at feedout weekly, especially for high‑moisture feeds.
 
Option: Sampling at Harvest
Sampling forage as it is chopped and placed in the silo has major advantages:
  • Easier access to representative material
  • Laboratory results available before feeding begins, enabling:
    • Better feed inventory allocation
    • More accurate ration planning
    • Earlier decisions on supplement purchases
Note: Some values (DM and protein solubility) change during fermentation, but CP, ADF, and NDF remain relatively stable when ensiling is done correctly.
However, improper ensiling may alter nutrient results:
  • Too wet: seepage, nutrient loss
  • Too dry: heating, reduced quality
  • Poor fermentation: inconsistent analysis, reduced intake
 
Ensuring Representative Samples at Harvest
Distribution of plant parts within a chopper box is not uniform:
  • Leaves (lighter) accumulate toward the back and sides
  • Stems (heavier) accumulate near the center
To obtain an accurate sample from wagons unloading into a blower:
  1. As each load is unloading, take three samples from the center of the forage stream using a shovel.
  2. Combine subsamples from several loads from the same field and hybrid.
For bunker silos:
  • Collect samples from the middle of the wedge at several points during filling.
Do not freeze fresh forage, as freezing may falsely increase measured fibre levels by 3–6%.
Send samples to the lab immediately after collection.
 
Sampling Silage During Feedout
Sampling Silage from a Pit (One week prior to feeding)
  • Scrape across the silage face, similar to how material is removed during feeding.
  • Gather the loosened silage to form a single pile on the ground.
  • Collect six to eight hand‑grab samples from different spots within the pile.
  • Place the collected material into a sample bucket and mix thoroughly.
  • From the mixed material, take a couple of well‑packed handfuls to fill the sample bag.
Silage should be resampled when:
  • Seepage is observed
  • Heating or mold appears
  • Moisture or feed characteristics change
Routine monitoring:
  • Check dry matter weekly
  • Adjust ration formulation accordingly
This ensures better feed consistency and reduces risk of ration imbalances.
 
Summary
Effective silage sampling—both at harvest and during feedout—is essential for:
  • Accurate ration balancing
  • Stable animal performance
  • Least‑cost feeding strategies
  • Reliable inventory management
Silage quality is dynamic. Frequent, well‑collected samples provide the best opportunity to manage these changes and maintain high‑quality forage use throughout the feeding season.