Chris Shelley, CSU Extension Area Livestock Agent
Cattle belong to a group of animals with very complex digestive system called ruminants. They utilize many forages (hay) very efficiently, making it easy to overlook the importance of forage evaluation. Cattle performance is highly influenced by the quality of the diet. Obtaining forage quality results through representative sampling and testing is critical for hay marketing, animal nutrition and livestock production goals.
Whether you seek analysis on crude protein, TDN or nitrates, incorrect sampling of baled forages will lead to lab results that do not represent the actual quality. The National Forage Testing Association (NFTA - www.foragetesting.org) has established 10 best practices summarized below. Following these steps will help to collect a representative sample of your hay.
1. Identify a single ‘lot’ of hay.
· Less than 200 tons
· Must be from the same field, cutting and forage type
2. When to Sample?
· Hay quality can change, especially during the first 22 days after harvest and storage
· Sample as close to feeding as possible
3. Choose a sharp, well-designed coring device.
· Do not collect grab samples
· Select a probe diameter of 3/8 - 3/4 inches and a depth of 12 - 24 inches
· Maintain sharp tips that are not angled (90 degrees to shaft)
4. Sample at random.
· Make every attempt to randomize which bales are chosen for sampling
· Choosing or avoiding bales based on appearance or quality introduces bias and may not accurately represent the lot
5. Take enough cores.
· Minimum of 20 cores per hay lot
· Sampling more bales generally represents the lot more accurately
6. Use proper technique.
· Sample butt ends of square bales or curved surface of round bales
· Avoid edges and insert probe at a 90 degree angle
· For round bales, sample towards the center and do not sample flat sides
7. Sample amount: “not too big, not too small”.
· The 20+ cores should result in a 1/2 pound sample
8. Handle samples correctly.
· Seal samples in plastic bag - double bagging is beneficial
· Protect from heat and sun light
· Send sample to the lab as soon as possible
9. Never split samples without grinding.
· It is okay to double check the performance of a lab with another lab
· Do not split samples unless they have been ground
· It is okay to ask for unused sample back from labs to send to another lab (easy to include in the notes or special instruction section on your sample submittal form)
10. Choose an NFTA-Certified Lab.
· The NFTA is a volunteer group set up by growers
· NFTA certified labs have demonstrated commitment to good results
For additional information, visit the NFTA website at www.foragetesting.org or contact your local extension office.