Agriculture

Proper Hay Sampling
To obtain a reliable forage test, the sample sent to the lab must accurately represent the entire hay lot. Although a hay stack may contain hundreds of thousands of pounds of variable forage, the lab typically analyzes less than 0.5 grams of material.
Because sampling variation is far greater than laboratory error, poor sampling can lead to costly mistakes—affecting ration formulation, livestock performance, and buying/selling decisions.
Carefully following a standardized sampling protocol greatly reduces variation and produces trustworthy forage quality estimates.
 
1. Identify a Single Lot of Hay
A hay lot should consist of:
  • One cutting
  • One field
  • One variety/type
  • Generally less than 200 tons
Do not mix different cuttings, fields, or hay types into one sample. Each lot must be sampled and tested separately.
 
2. When to Sample
Sample hay as close to feeding or point of sale as possible.
Key points:
  • Hay undergoes a “sweat” period after baling where moisture and heat change.
  • Moisture content typically declines in the weeks after harvest.
  • Wet-baled hay may mold or, at very high moisture, create fire risk.
Use “as-received” DM only for tonnage calculations;
all quality comparisons must use 100% DM basis.
 
3. Use a Proper Coring Device
A well‑designed core sampler is essential.
Coring Device Requirements
  • Diameter: 3/8–3/4 inch
  • Tip: 90° to the shaft (not angled)
  • Sharp, well‑maintained
  • Probe length: 12–24 inches
Avoid:
  • Grab samples or flakes (unrepresentative)
  • Small-diameter probes (<3/8”)
  • Oversized probes that produce too much sample
The tool must:
  • Penetrate bales easily
  • Cut cleanly without creating fines
  • Yield ~½ pound (200 g) of composite sample in ~20 cores
 
4. Sample at Random
Move around the stack and take samples without bias.
Random Sampling Tips
  • Sample both ends of accessible bales.
  • Vary your pattern (e.g. 15 steps–sample, 20 steps–sample).
  • Do not choose bales that “look good” or avoid ones that look poor.
Random sampling ensures the composite sample reflects true variation in the lot.
 
5. Take Enough Cores
A representative sample requires at least 20 cores, regardless of bale size.
Recommended Core Numbers
  • Small square bales: 1 core per bale, ≥20 bales
  • Large round/square bales: 2–3 cores per bale from ≥10–12 bales
  • Variable or large lots: up to 35 cores
Variation between bales can be large (5–7% CP or ADF), so more cores improve accuracy.
 
6. Use Proper Sampling Technique
  • Sample the butt end of square bales between strings or wires.
  • Insert probe straight (90° angle) to a depth of 12–18 inches.
  • For round bales, sample toward the center from the curved side.
  • Do not sample the top, sides, or same spot twice.
 
 
 
Technique must preserve the leaf‑to‑stem ratio, which strongly affects nutrient analyses.
 
7. Provide the Correct Sample Amount
Target composite sample size: ~½ pound (200-500 g). Large freezer bag (8X10) full is optimal.
  • Too-small samples fail to capture variation.
  • Oversized samples may not be fully ground by the lab—reducing accuracy.
  • Ensure your lab grinds the entire sample, not a subsample.
If your probe doesn’t yield the right amount in 20 cores—choose a different probe.
 
8. Handle and Deliver Samples Properly
Preparing the Sample
  • Place the composite sample in a sealed plastic bag; double‑bag for moisture tests.
  • Keep cool and out of sunlight.
  • Deliver to the lab promptly.
  • Refrigeration helps preserve samples, though dry hay (~90% DM) is generally stable.
  • Label each plastic sample bag before filling it, using a permanent black marker.
  • Clearly write:
    • Sample number
    • Your name
    • Type of feed
      Example: “#1 Joe Smith – 2nd Cut Alfalfa/Grass Hay”, “#2 Joe Smith – Corn Silage”, “#3 Joe Smith – Oat Greenfeed”
  • Seal the sample bag securely and place it in a small box, padded envelope, or Purolator bag.
Completing Paperwork
  • Fill out the Chain of Custody submission form and place it inside the package with your samples.
    • Include your email address for electronic results.
    • If no email is provided, results will be mailed.
  • Calculate the total cost for each analysis package plus 5% GST.
  • Include either:
    • a cheque, or
    • detailed contact information so the lab can obtain credit card payment.
Shipping the Sample(s)
  • Ship early in the week; do not send samples on Thursday or Friday.
  • Dry samples (hay, grain, etc.) may be shipped via Canada Post or Purolator.
  • Wet samples (silage) must be shipped via Purolator.
  • Include the completed Chain of Custody form and payment.
  • Producer is responsible for shipping costs.
  • A shipping label is included in the package.
Lab Shipping Address
Central Testing Laboratory Ltd.
Unit 9 – 851 Lagimodiere Blvd.
Winnipeg, MB R2J 3K4
Phone: 204-237-9128
 
9. Never Split Unground Samples
When comparing lab performance:
  • Do not split unground samples—each portion may contain different material.
  • Use the ground sample to divide between labs.
  • Send multiple samples to detect consistent lab biases.
A reputable lab should be willing to support validation checks.
 
 

10. Selecting a Feed Analysis Package

Refer to the enclosed Feed Test Analysis Packages and Costs document for full details. Central Testing Laboratory uses two analytical methods: Wet Chemistry and Near Infrared Spectroscopy (NIR).
 
Wet Chemistry
  • Most accurate method.
  • Involves chemical analysis of the sample.
  • More expensive and takes a few days longer to process.
  • Preferred for ration balancing due to higher precision.
  • Recommended for non-typical or unusual feed types.
 
Near Infrared Spectroscopy (NIR)
  • Uses light reflection to compare the sample to benchmark databases.
  • Generally less accurate and more variable.
  • Suitable for common feeds, such as:
    • Alfalfa-grass hay
    • Grass hay and silage
    • Cereal greenfeed and silage
  • Not recommended for:
    • Uncommon forages (e.g., cattails, canola hay, pea straw)
    • Mixed or unusual crop combinations
  • Extreme growing conditions (drought, stress, etc.) may reduce accuracy.
  • Commonly used for general information purposes, including hay sales.
 
Pricing & Additional Information
For current pricing and a complete list of available analyses, contact Central Testing Laboratory:
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