Almost anyplace in the U.S. blessed with ample spring moisture and warm temperatures is also blessed with explosive spring pasture growth. One of the major challenges for grazing operations in such environments is keeping spring pastures from getting out of control and turning into summer stems and seed heads.
There's a delicate line between overgrazing too early and running out of grass, or getting out too late and having everything turn into a hay crop before you can get it grazed. Hitting the balance is what spring-grazing management is all about.
Continuous grazing concerns
Finding this balance is particularly challenging in a continuous-grazing operation, where a fixed number of animals typically are put into a single pasture and expected to be there for several months. The most common solution to excess forage is to harvest the surplus as hay for later feeding. But, with producers increasingly trying to minimize the high costs of hay making, other solutions are needed.
One solution for a continuous-graze operation is to increase spring stocking rate by using stockers or cull cows to increase grazing pressure. As pasture growth slows in early summer, the added animals can be sold or shipped for finishing. The availability of animals, market trends and price volatility are the big question marks with this strategy.
In the fescue belt of the eastern half of the U.S., where tall fescue makes up much of the pasture, a fall-calving system using spring-weaned calves as a stocker program can help increase spring grazing pressure.
Avoid using spring nitrogen (N) fertilizer to stimulate additional growth if pastures are consistently getting out of control. Applying N at 60 days or more into the grazing season provides a better late-season forage supply.
Managing the spring flush is much easier in an intensive rotational grazing system if you adhere to the guidelines of getting out early and moving fast. What is early and what is fast are the big questions.
Getting out early
Most grazing regions have developed spring turnout dates based on many years of continuous-grazing experience. For instance, serious graziers across many environments have moved up spring turnout by 2-4 weeks to keep spring pastures under control and produce high-quality summer pastures. Why does this work in a rotational system but not with set stocking? Rest is the simple answer.
With set stocking, if you put the animals out too early, the pasture never gets a chance to recover from early grazing pressure. If the season turns dry, or is otherwise unfavorable to growth, pastures don't recover.
Under a rotational system, rest is a planned part of the program. Thus, early-grazed pastures get a rest when growing conditions are still ideal, and they rapidly catch up to totally ungrazed pastures.
Our goal in high rainfall or irrigated environments is to graze every acre of pasture twice in the first 40 days of the grazing season. In many non-intensive rotation programs, not all the pastures get grazed even once in the first 40 days, which is a sure way to produce low-quality summer pastures.
Getting everything covered in the first cycle may mean grazing more than one pasture at a time or moving very frequently. In a system using portable fence to create paddocks, just make springtime paddocks much larger than would be normal during the summer grazing cycles.
In this first cycle, we're not trying to graze every paddock to some ideal level. We're just trying to get a bite off every plant we can. The goal through these first 40 days of grazing is to get the newly elongating seed heads bit off before they reach the boot stage. In the immature stage, seed heads are high quality and readily digestible. We want cattle to eat them early so we don't have to force them later. Even worse is having to get out the brush hog.
Keeping spring pasture under control is driven by these two factors — get out early and move fast. These are powerful management tools if used effectively.
(Note for range grazier readers: These guidelines are for eastern high rainfall pastures and western irrigated pastures, not semi-arid rangeland.)
Jim Gerrish is a grazing management consultant based in May, ID, and former lead pasture researcher at the University of Missouri's Forage Systems Research Center in Linneus. Reach him at 208/876-4067, firstname.lastname@example.org, or visit http://americangrazinglands.com.