A comparison of on-farm methods for estimating the dry matter content of feed ingredients

On-farm methods for determining the DM content of ensiled feed ingredients were evaluated to determine ease of use, time required to conduct the determination, repeatability, and accuracy relative to a standard drying method. Methods evaluated were sequential drying in a microwave oven, Koster tester method, and electronic moisture tester method. A drying oven was used as the standard drying method. Feed ingredients evaluated were alfalfa silage, corn silage, and high moisture shelled corn (unground kernels). All on-farm methods gave highly repeatable DM results. The microwave oven method was more accurate than the standard method but required the most time to perform. The Koster tester tended to underdry feed ingredients and was not as repeatable as the microwave method. The electronic moisture tester was comparable with the other on-farm methods for alfalfa silage and most closely agreed with the standard method for high moisture shelled corn. However, compared with the standard method, the electronic moisture tester did not accurately determine the DM content of corn silage. The electronic moisture tester required the least operator skill and time