Set the Stage Now for the Rest of the Grazing Season

We are at a stage now where we can affect grazing for the season. Right now our fields are finishing up their “reproductive” stage of growth as our grasses are setting seed heads and our legumes are blooming. After they set seed, perennial plants transition from the reproductive stage to the vegetative stage. Up to this transition, energy of the plant has been moving up from the roots to the seeds, but with this transition, energy movement will primarily move from the leaves to the roots. This is a good thing as it will help build up root reserves to help the plant survive the winter.
What can we do to help this? Removing the seed heads will stimulate new leaf development to build root reserves and provide more growth for grazing. Some of this can be accomplished by grazing livestock, but we may need to clip the fields. If livestock have been out of the field for a period of time, cutting for hay is an excellent option. The other option is to clip or rotary cut the fields. Either of these options will stimulate more leaf growth than no seed head removal at all.
The height at which we clip the fields will make a difference. Have you ever noticed after a field is clipped and has a chance to grow that livestock will tend to not graze below the cutting height unless they are left in a field too long? This is a tool we can use to encourage certain types of plant production. For example, if I am trying to encourage orchardgrass growth, I would want to clip my field high, say five inches. If I am trying to encourage bluegrass growth or reduce fescue, I would cut much closer.
Clipping pastures higher has another advantage. Removing the seed heads and leaving more leaves will provide shade for the soil and reduce evaporation. The additional leaves will gather more energy for the roots. If we receive one of those gully washers in July, the additional cover will allow much more moisture to soak into the soil and not run off, providing more growth for the plants.
Remember, if forage growth is more than what your animals can use right now, consider removing some of the paddocks for hay, then they can go back in the rotation after pasture growth slows down. Continue to monitor fields frequently as growth will start slowing down in the next month and we do not want to overgraze paddocks. Letting them grow to proper heights and not grazing too close will allow for more forage availability for the entire season. If growth slows down too much, we are better to put them in a sacrifice lot and feed stored forages than to let them graze all of the paddocks down. If animals are removed prior to plants being grazed too close, new growth will start from the leaves without a reduction in root reserves. If they are grazed too close, root growth will stop and new growth will need to start from root reserves, weakening the plant.
There are two reasons why we recommend taking half and leaving half (keep in mind that the forages become denser closer to the ground). The first is it gives the plants more ability to capture more moisture during a heavy rainfall, reducing runoff. The second is the closer animals graze the forages, the more root growth will cease. When animals graze 40% or less of the growth, there is no root growth stoppage. When 50% is removed, only a few % of the roots will cease growth. At 60% plant removal, 50% of the roots will stop growing. Finally, at 80% removal, 100% of the roots will stop growing. The message here is the closer you graze, the longer it will take the plant to recover if it is not killed.
So, how tall should the pasture be before we graze and how close can we graze it? Tables 1 & 2 provides guidelines for grazing height.

Table 1 Managing Grazing Height for Pure Grass Stands

Species

Perennial Ryegrass pre graze 6-7" post graze 3"
Orchardgrass pre graze 8-10" post graze 4-5"
T. Fescue (E+) pre graze 5-6" post graze 1-2"
T. Fescue (E-) pre graze 8-10" post graze 4-5"
Brome grass pre graze at Pre or late jointing, post graze 2-3"
Timothy pre graze at Pre or late jointing. post graze 4"

(Source: Ohio Integrated Forage Management Team)

Table 2 Managing Grazing Height for Grass/Legume Mixtures

Species

Bluegrass/w clover, pre graze 4-5" post graze 1"
OG/L clover, pre graze 6-8" post graze 2"
T fescue/L clover, pre graze 5-8" post graze 1.5 - 2"
Alfalfa with grass, pre graze bud stage, post graze 2"
Red clover with grass, pre graze bud stage, post graze 2"

(Source: Ohio Integrated Forage Management Team)

Finally, now is a good time to consider fields that could be stockpiled for fall and winter grazing. After our first cutting of hay, we should have a good idea of what our winter feed needs will be. If quantity will be our biggest need, we can start stockpiling forages, especially fescue in July. If quality is a more pressing need, we can wait to stockpile in August. In either scenario, 50 pounds of nitrogen should increase yields by 1500 pounds/acre and increase protein content.
There are several things we can do now to influence the quality and quantity of our pasture fields for the rest of the season. We simply need to evaluate our needs and plan accordingly, take action, and hope that Mother Nature cooperates.