Transitioning to Pastures

The last week or two has been refreshing with warmer temperatures and pastures beginning to green up. As that green flush appears, it can be tempting to turn animals out too early. However, many pastures across the state have taken a hit in recent years due to drought and/or flooding. As of October 28, 2024, much of the state was still experiencing drought conditions, with soil moisture deficits extending from the surface down to 1.5 feet (Figure 1). In fact, many producers began supplementing with hay as early as September due to limited pasture regrowth.

While much of the state has started to recover from these moisture deficits (Figure 1), pasture recovery this spring may still be slow. Waiting until pastures are truly ready is important for long-term stand health and recovery. Starting the grazing season off right sets the tone for productivity the rest of the year.

So, when should we release animals to pasture?

If using continuous stocking, it's recommended to wait until pastures are at least 8 to 10 inches tall. This helps avoid overgrazing and supports root health and regrowth.

For rotational grazing, you can start earlier—at 4 to 6 inches—if you're moving animals very frequently (at least daily). Waiting until 8 to 10 inches in a rotational system may mean grasses are entering the exponential growth phase, making it difficult to keep up and resulting in overly mature forage by the time you reach every paddock. Early, frequent moves help keep the grass in a vegetative state and can reduce pugging during wet periods.

Additionally, as you start transitioning animals to pasture, do so strategically. A gradual transition by continuing to supplement with high-quality dry hay, can help animals adjust from a dry forage diet to one high in moisture (Figure 2). Spring pasture growth tends to be low in effective fiber, and rumen microbes need time to adjust. A sudden shift to this lush forage can lead to digestive issues like diarrhea.

Lastly, be mindful of nitrogen (N) and potassium (K) applications to avoid grass tetany, which is caused by low magnesium absorption. High levels of N and K can interfere with magnesium uptake, so balanced fertilization is key. Lime, phosphorus (P), and potassium applications should ideally be completed in the fall and guided by soil test results.

As for nitrogen: split applications of 30–60 lbs N per acre are ideal, timed with plant growth for best uptake. Applying N before first grazing is usually unnecessary, as spring growth is already vigorous. Adding N at this time can result in excessive forage that’s difficult to manage unless you plan to harvest it for stored feed. Instead, consider applying after the first and second grazings and again in the fall to better distribute growth throughout the season.

Also, remember: if your pastures contain more than 30% legumes (on a dry matter basis), N applications are typically not cost-effective. Legumes naturally fix nitrogen, which can meet much of the grass component’s needs.

Overall, let’s start the season off right:

• Delay turnout until pastures are ready to support grazing.
• Ensure animals have a balanced diet during the transition period.
• Be intentional with your fertilization strategy to support forage growth and animal health.