RBC I Rain this year has been wonderful for the recovery of drought-damaged range land, but not all hay was put up in great shape. Remember, when plants are cut for hay, they do not immediately die.
Dry matter loss of 5 percent per inch of rain is possible. As long as moisture is above 40 percent, they will continue to respire (exchange oxygen and carbon dioxide) a process that burns energy. This can lead to losses in quality and a loss in dry matter.
When rainfall occurs after a cutting, the timing will also influence quality. If rain occurs immediately after cutting, the plant cells are still relatively turgid, or firm, from retained water, and, though some losses will occur, little moisture will enter the cells and leach the water-soluble cell contents.
If plants have been drying a couple of days and then are rained on, plant cells will re-absorb moisture and a greater leaching of cell contents will occur.
Sometimes rain will not reduce hay quality significantly; the only way to know for sure though, is to test the hay. Losses of more than 3 percent protein and 10 percent TDN (energy) have been documented.
NDF (non-digestible fiber) increases, thus lowering the energy value of the hay. A study in Kentucky found that 90-95 percent of the Vitamin A was lost when hay remained in the windrow for three weeks.
In the rush to get hay baled between rains this year, some hay may have been baled with extra moisture. At these moisture levels, there will be an increase in mold, which leads to animal refusal and increased dry matter losses.
If mold has occurred, it is also a sign that a drop in energy has taken place as the sugars (energy) in the hay have been used to fuel the growth of the microbial population.
If hay appears to be brown, we can be sure there is some damage. It may, however, look fairly good. To be sure, why not get a forage analysis?
I would be happy to come and pull samples or you may check out equipment and collect samples yourself. When results are returned, then pricing of hay can be determined based on the hay quality. From the results we can also establish rations for your livestock.
Please call Bill Ekstrom, the CSU Extension Agent for Rio Blanco County at 970-878-9494 for more information or assistance.