For those of Southern ilk, the pasture gate has likely already been opened to grass of 2016 vintage. For others, it may still be too early. Either way, spring pasture management has a big impact on productivity for the remainder of the growing season. It can make it or kill it.
“There’s no single date that is right to initiate grazing,” says Victor Shelton, NRCS state grazing specialist in Ohio. “It’s just not that easy.”
Shelton emphasizes the need for paddock evaluation and a game plan. “Fields that were stockpiled last fall and had the most regrowth will generally be the first ones to green up and grow,” notes Shelton in a recent Ohio Beef Cattle Letter. “These fields typically have the most root reserves. Conversely, fields that were grazed hard last fall prior to going dormant have low root reserves and will need comparatively more time before being grazed,” he adds.
The grazing specialist recommends starting to graze cool-season grasses when plants are about 6 to 8 inches tall and soils are dry enough to support livestock without causing damage to plants. Fields with more residue generally have a stronger root base and can support cattle earlier. Fortunately, these are often the same paddocks with the most growth.
“In rotational systems, there is some advantage to start grazing early. This will help to keep pastures from getting too far ahead before livestock can get to them. The key, however, is to move animals through the system quickly so as not to overgraze some paddocks while at the same time others become too mature,” says Shelton.
Spring is perhaps the most important time of year to routinely walk all of the paddocks and note growth height. From this information, a grazing plan can be developed and the forage quality of grazed paddocks is maintained. This may mean some paddocks will be skipped and left for hay production during the first cycle or two of the rotation.
Shelton emphasizes the need to keep animals moving quickly through the system as grass growth rate is in full gear. Once grass growth begins to slow, so can animal movement. “Never graze closer than 3 to 4 inches. Keep grazing new paddocks until the initial paddocks grazed have grown back to 6 to 8 inches. If you wait too long, frustration quickly sets in as you try to play catch-up,” says Shelton. “The goal is to keep pastures vegetative.”
There is also some strategy in deciding which paddocks will be skipped and designated for hay production. Those with thin soils, low fertility, or perhaps are late to dry out are the best candidates for additional rest and subsequent hay production.
Shelton also reminds livestock producers to boost the amount of magnesium (Mg) in the mineral mix. Early spring pasture growth is often low in Mg, leaving cattle prone to grass tetany. This is especially true on fields where nitrogen and/or potassium have been recently applied or where levels of these nutrients are excessive.