P#3 Collecting forage samples.pptxhhhhhhhj

P#3 Collecting forage samples.pptxhhhhhhhj

1. Collecting Forage Samples for Analysis by Muhammad Rehan

2. Importance of Forage Sampling • Forages provide energy, protein, vitamins, minerals, and fiber. • Quality depends on variety, growth stage, weather, and handling. • Laboratory testing gives true feeding value. • Representative sampling ensures accurate results.

3. Why Proper Sampling Matters • Poor sampling leads to wrong lab results. • Wrong results cause incorrect feed planning. • Always collect representative samples from each forage lot.

4. Sampling Equipment • Forage probe (manual or electric drill mounted). • Bucket for mixing samples. • Sample bags for storage. • If no probe, use shears/scissors (cut 2–3 inch pieces). • Reduce sample size with the Quartering Method.

5. Quartering Method (Sample Reduction) • Mix the full sample on a clean surface. • Flatten and divide into four equal parts. • Keep two opposite quarters and mix again. • Ensures an unbiased smaller sample.

6. When to Sample • Sample close to feeding or sale time. • Allow two weeks for lab results. • NIRS labs may give results within an hour. Near-Infrared Reflectance Spectroscopy

7. What to Sample • Test each forage lot separately. • A lot = forage of same species, maturity, and field. • Differences in lots affect feeding value and price.

8. Sampling Small Square Bales • Select 20 average bales. • Core one end of each bale at right angle. • Mix all cores in a bucket. • For hand sampling, take handfuls, cut, and mix.

9. Sampling Large Round Bales • Select 10 bales, take 2 cores per bale around the edge. • Use a long probe angled slightly upward. • Mix all samples thoroughly. • Sample 2–4 weeks before feeding or sale.

10. Sampling Large Square Bales & Loose Hay Stacks • Large square: probe each end of 10 bales. • Loose stacks: take 3 cores diagonally (top, middle, bottom). • Mix all samples well. • Sample 2–4 weeks before use.

11. Sampling Cubes, Pellets & Standing Forage • Take samples from at least 6 points around the pile or bags. • Avoid fines or dust. • For standing forage: clip 8 spots (1 sq. ft.), cut, dry, and mix. • Air-dry for 2 days or oven-dry at 150°F.

12. Sampling for Nitrate Testing • Nitrate toxicity is dangerous to livestock. • Collect samples from suspected bales or field areas. • Use Diphenylamine field test (blue color = nitrate). • Confirm through lab testing.

13. Diphenylamine test   The  Diphenylamine field test  is a  simple and quick test  used to detect  nitrates  in forage or plant tissues before feeding animals. It helps identify potential nitrate poisoning risks in hay, silage, or green forage. Purpose To identify if a forage sample contains  high nitrate levels  that can cause toxicity in livestock.

14. Materials Needed Diphenylamine reagent  (usually 1 g diphenylamine in 100 mL concentrated sulfuric acid) Test tube or small glass container Dropper or glass rod Freshly cut forage sample  (stem or leaf pieces) ⚠️  Safety note:  The reagent is  corrosive . Handle with gloves and eye protection.

15. Interpretation Color Reaction Meaning Deep blue or dark purple High nitrate concentration (potentially toxic) Light blue color Moderate nitrate level (caution advised) No color change Safe nitrate level (non-toxic)

16. This is a  qualitative test  — it shows  presence , not exact nitrate amount. If a strong blue color appears, send a  sample to a laboratory  for confirmation and precise measurement. This test is useful for  quick field checks  before harvesting or feeding green forage

17. Sampling Silage (General) • Use grab samples; probes not suitable. • Avoid top and bottom 2–3 ft (moldy parts). • Mix and reduce to 1-quart sample using quartering.

18. Fresh-Cut and Upright Silo Sampling • Collect 2–3 gallons from each load, freeze samples, and combine later. • Avoid weekend mailing (may cause mold). • From upright silo: collect 12 handfuls while unloading, mix, and reduce.

19. Horizontal Silo Sampling • Take grab samples from across the silo face. • Avoid top/sides (spoiled silage). • Mix and quarter to one quart for testing.

20. Submitting Samples for Analysis • Submit through County Extension Office. • Use cloth bag inside a plastic bag (for moisture samples). • Label with pencil only. • Results given on wet, as-fed, and dry-matter basis.

21. Key Takeaways ✅ Always collect representative samples. ✅ Use a forage probe when possible. ✅ Mix and quarter samples carefully. ✅ Avoid wet or spoiled material. ✅ Label and seal samples properly.