Methods of Forage Moisture Testing

Determining forage moisture is an essential procedure for estimating forage mass in pastures, determining harvesting or baling point for preserved forages, and calculating dry matter of feedstuff for total mixed rations. Target moisture for hay is between 13% and 15% (85%–87% dry matter), while it ranges from 40%–60% (60%–40% dry matter) for baleage, and up to 65% moisture (35% dry matter) for silage. Baling or harvesting at higher moisture can lead to spoilage or spontaneous combustion in hay, or butyric fermentation in silage. However, low moisture can prevent silage from properly fermenting, resulting in slow and low pH reduction for proper storage. There are several methods and pieces of equipment available to estimate forage moisture. Electronic methods such as moisture probes are quick, but they give more variable results than a microwave or forced-air heating unit such as the Koster Tester.