Taking a Good Feed Sample
An analysis is only as good as the sample submitted. Taking a good representative sample of your feed is the first and most critical step of the analysis process, yet it is often the step that is the most taken for granted. Following good sampling procedures will help ensure that your analytical results truly reflect the nutrient composition of your sample and will be useful in developing your feeding program. Poorly taken samples can result in decisions that lead to either over or under feeding. Both can be costly in terms of money and/or lost production.
The key to submitting a good feed sample is to collect several sub samples to form a composite. Remember that the one-pound sample that you submit for analysis is going to represent several tons of feed. Thus, you want to be sure that it represents a good cross-section of the feed, not just one bale. There can be a great variability between bales in the same lot. For example, if you sampled the worst bale in the lot, feeding recommendations based on this information would result in overfeeding and increased feed cost. Studies have been done demonstrating that compositing multiple sub samples is the best way to get an accurate picture of the forage in question.
Guidelines
Hay – Hay of different types, cuttings or lots should be sampled separately. Using a suitable hay probe, bore 12-20 bales selected at random through the small square end. Combine all core samples and submit for analysis.
Silage – Collect only fresh unloaded material. Grab handfuls of silage from 12-20 locations in the unloaded silo pile, feed bunk, or from in front of 12-20 cows. For bunker or trench silos, collect 12-20 samples from across the face of freshly exposed material. Sampling locations should vary from top to bottom and left to right. All sub samples should be combined and mixed thoroughly in a clean plastic bucket to form a composite sample. Submit one-pound (0.5 kg) of the composite for analysis.
Another option is to load a mixer wagon with silage, blend for a few minutes, and then grab a sample from the discharge.
Total Mixed Rations – Collect only freshly blended rations. Grab 12-20 handfuls of the mix from different locations in the feed bunk or from in front of 12-20 cows. All sub samples should be mixed in a clean plastic bucket to form a composite. Submit a one-pound (0.5 kg) sample of the composite for analysis.