Decisions Made Now Can Impact The Entire Grazing Season

By Chris Penrose

Considering how early our forages broke dormancy this year, we will soon reach a stage where our forage management decisions can affect grazing for the entire season. In 2012 when we also experienced a very early spring our forages were finishing up their “reproductive” stage of growth with grasses setting seed heads and legumes blooming by late April. After they set seed, perennial plants quickly transition from the reproductive stage into the vegetative stage. Up to this transition, energy of the plant moves up from the roots to the seeds, but with the transition, energy movement will primarily move from the leaves to the roots. This becomes a good thing as late in the summer it will help build up root reserves to help the plant survive the winter.

In the meantime, let’s look at what can we do to help keep plants vegetative and productive as possible.

Orchardgrass pictured in head on April 30, 2012 in Fairfield County

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 also need to clip some fields. If livestock have been out of a field for a period of time, planning to cut a portion of those pastures for hay is an excellent option. The other option is to clip or rotary cut the fields. Either one 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 leaf 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 into the grazing rotation after pasture growth slows down. Continue to monitor fields frequently as growth will start slowing down as summer approaches 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 cattle 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.

Root growth does not cease until 50 % of the leaf is removed. This is one of the reasons we recommend taking half and leaving half of the leaf.

So, how tall should the pasture be before we graze and how close can we graze it? Tables 1 and 2 provide guidelines for grazing height.

Table 1: Managing Grazing Height for Pure Grass Stands

Species

* You may want to graze closer to four inches during summer months as the endophyte can accumulate more at the base of the plant and graze closer in the winter months.
(Source: Ohio Integrated Forage Management Team)

Table 2: Managing Grazing Height for Grass/Legume Mixtures

Species

(Source: Ohio Integrated Forage Management Team)

Finally, it’s never too early to consider which fields 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 1000 pounds/acre and also increase protein content.

As spring gets upon us, there are several things we can do 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.

Source:osu.edu