Feed Sampling & Analysis
Representative Sample Identify a “lot” of hay Same field harvested within 48 h Other variables – variety, soil, weeds Small sample represents “a lot” of hay
How to Take the Sample? Use a strong, sharp coring device At least 12” to 18” long Right angle to bale
Where to Take the Sample? Ends of square bales Sides of round bales
How Many Bales to Sample? Minimum of 20 bales per “lot” Take more if variability high Sample bales at random Around the entire stack or yard Different heights Have a plan
Pasture Sampling Identify uniform area as “site” Approximately 20 plots per site But, forage maturity changes
Silage Sampling 3 to 5 handfuls from the middle of a load Plastic bag, refrigerate immediately Repeat several times during day
Grain Sampling Grain probe At least five cores Approximately 1 lb total
Handling Samples Combine “cores” of one “lot” Hay or grain – store in sealed freezer bag Fresh forage – store in paper bag Send to lab quickly
Proximate Analysis Water Crude protein = %N x 6.25 Crude fiber (CF) Ash Ether extract (EE) Nitrogen-free extract (NFE)
Proximate Analysis Nitrogen-free extract (NFE) = 100 – (%water + %CP + %CF + %Ash + %EE) Estimates non-structural CHO
Total Digestible Nutrients %TDN = (% dig x %CF) + (% dig x %NFE) + (% dig x %CP) + (2.25 x % dig x %EE) (0.50 x %CF) + (0.90 x %NFE) + (0.75 x %CP) + (2.25 x 0.90 x %EE)