Reducing the curing time is of critical importance in haymaking. Dry matter losses due to respiration, ranging from 4 to 15 percent, continue until the plant moisture content is reduced to approximately 35 percent. Dry matter losses associated with leaf shattering during the curing process have been estimated to range from approximately 2 to 5 percent for grasses and 3 to 35 percent for legumes. Prolonged periods of curing also increase the potential for losses due to rainfall. Leaching, leaf shattering and excessive biological decomposition are common consequences of rainfall during field curing.
Rain also can indirectly contribute to losses during curing.
Rain-soaked hay frequently requires additional raking, resulting in further leaf shattering. All the various kinds of dry matter losses that occur during haymaking contribute to serious losses in nutritive value. This is because the most nutritious components of the plant are most susceptible to loss. Therefore, management practices that reduce these losses will result in hay quality improvement. Chemical treatments can reduce dry matter losses during field curing.