Proper defoliation techniques, by grazing or mechanical harvesting, are an important part of improving forage management. Timing, severity, and frequency of defoliation determine the plant’s ability to regrow and the quality of the forage removed.
Two issues that are key to success are: (1) maintaining sufficient leaf area for photosynthesis and storage carbohydrates and (2) preserving regrowth meristems. Detailed information on these concepts is provided in the “Grass Growth and Regrowth for Improved Management” web segment.
Grazing is the process of allowing livestock to defoliate forages. It is often the lowest cost way of harvesting a forage crop, since the animals do most of the work for you.
Two primary grazing methods are set stocking and rotational or management intensive grazing (MIG).
Set stocking systems allow livestock to remain on pastures for extended periods and to select the forage of interest. These systems often result in highest per animal performance.
MIG systems allocate portions of the pasture for short time periods, typically using high tensile electric fence. These systems result in highest per area production.
Mechanical harvest uses choppers and/or swathers and conditioners, rakes, tedders, balers, and bale collection machines to remove forage and prepare it for later use as silage or hay.
This defoliation method is more costly than grazing and requires special machinery, but allows the forage to be conserved for times of low pasture growth or to be sold off the farm.