For most beef cattle farmers who are managing their pastures in a rotational grazing system two of the biggest spring challenges are the flush of rapid growth that will occur and selective grazing. While there are no easy management answers, if we review some basic plant growth biology and grazing principles, they may suggest some management strategies. Warning: this article may disrupt some conventional thinking.
We know that as spring progresses, grass growth will speed up. Our cool season pasture grasses produce about 60% of their total dry matter production by early July. If your farm has a stocking rate that is matched to summer pasture production there is no way your cattle will be able to consume enough pasture forage to keep up with the flush of grass growth that will occur in late April through May. Coupled with this explosion in grass growth is a physiological response to the shorter nights and longer days that triggers seed head production generally starting at some point in early May. So not only is there more forage than can be consumed, but now the quality is steadily declining as a seed head is produced. It is very hard to fight this biology. Fast grazing rotations where hopefully the cattle just top the grass, combined with clipping the pastures to keep seed heads off are some standard management practices that are tried. In reality, these are not great solutions because cattle are not grazing uniformly and are not just topping the grass. Instead they are picking and choosing. They are grazing some places harder than others, and leaving other places alone. The result is a patchy, uneven growth pasture paddock. The solution is typically to reset that paddock to an even height, while clipping seed heads. Clipping pastures can be very time consuming, not to mention the fuel and machinery costs that are incurred.
Instead of fighting the biology of spring grass growth, work with it. If your stocking rate is matched for summer production all of the pasture paddocks are not needed during the spring and early summer period. Paddocks should be dropped out of the spring rotation, and doing so will make it easier to manage the spring flush of growth. Which paddocks should be dropped out? Obviously any paddocks that had trampling and pugging damage during the winter and early spring are good candidates. This will give them time to recover, and/or for some paddock renovation and reseeding to be done. Next, drop those paddocks where it is easiest to get a tractor over. The goal is to use the pasture paddocks with the most slope where mechanical clipping would be difficult.