– Victor Shelton, Retired NRCS Agronomist/Grazing Specialist
The best stockpiled forage is late summer to fall regrowth – just don’t start grazing it too early.
When a lot of things that occupy your time or influence your pocketbook are impacted by the weather it is hard to not talk about it some! I felt it was a very odd growing season, at least in my neck of the woods. My reasons were certainly different than in other areas, even not that far away. The weather constantly reminds me that we need to always have a plan B and be prepared to act on it. It also reminds me that we need to build in as much resilience into the grazing system as possible.
I’ve been asked twice recently about what I consider “stockpiled” forage. Stockpiled forage is technically defined as standing forage that is allowed to accumulate for grazing at a later period, usually for fall and winter grazing after dormancy. Stockpiling usually is initiated anywhere from early August to the first of September. I like to see at least 60 days of forage accumulation prior to the first frost – that means it needs to be started by mid-August most years. This time frame allows enough time, with adequate rainfall, to grow a nice amount of forage for use after dormancy.
Waiting until after dormancy is important. Dormancy often requires several nights in a row at 25 degrees or lower. Once dormant, the forage can be grazed with less harm to the plant’s energy reserves. When it is grazed, it can be taken down a bit closer than normal but leaving good residual. That good stop grazing height will slow runoff over winter, reduce any erosion and help springboard growth next season.
Quite often, people get in too much of a hurry to utilize that stockpiled forage. This usually happens with systems that are running out of forage to graze. Stocking rates have increased on several farms the last few years – that is the number of animal units (1000-pound live weight) on the total acres. Quite often to more animal units than the land base can adequately support. When that happens, more “fed” feed is needed to support the animals present. That is quite often purchased feed. The pencil better be pretty sharp to make that work out well with present day prices.
A fair amount of marginal land that used to be pasture or hay land has been converted to cropland. If animal numbers were not adjusted, the stocking rate increased putting more pressure on the remaining acres. That generally means a shorter grazing season, quite often reduced production due to shorter rest periods, and again, increased inputs. Enough of that tangent.
Early grazing of stockpiled forage, prior to dormancy, reduces the plant vigor the following spring and quite often opens it up to more competition from weeds, especially if there was a lot of soil disturbance or over grazing occurred. Fields that have had increased weed pressure are probably not the best to stockpile and should be allowed to recover prior to dormancy and left ungrazed until the next spring.
When possible, such fields could also be stockpiled early and then left to be utilized early the next spring when both the cows and owners are eager to start grazing. That stockpile not only could help to reduce weeds due to stronger root systems and cover but can provide an excellent site for calving or such without mud.
I’ve seen several pastures that were stockpiled as recommended, but grazed too early, let to regrow and then grazed again. I’ve intentionally done this in some of my experiments and paid for it dearly. Not only was there a weakened forage stand the next spring, but the site was also more easily disturbed during any grazing event and that greatly increased weed pressure. That weed pressure appears from the seed bank present in the soil along with any new additions from equipment, movement with animals and certainly wildlife. Some weeds can lay dormant for decades just waiting patiently for the right opportunity and conditions to grow. Delayed spring grazing with a little extra fertility, especially nitrogen, helped to reduce weed pressure some by increasing competition by the desired forage, but not always.
What most producers really need is more grazable acres or fewer animal units. That is probably easier done by utilizing some cropland, especially marginal cropland, to grow annual forage in the rotation for haying or ideally grazing and making use of crop residue when conditions are favorable to do so without causing compaction or the need for cleanup tillage afterwards. If the livestock are off the pastures for several weeks, then it is a lot easier to rest pastures more and stockpile forage correctly and reduce the need to carry feed to them. Feed that the animal can harvest itself is almost always cheaper than anything that you have to carry to it.
I was asked recently again about the grazing of Johnsongrass during a farm visit. If the field is grazed very often, you usually won’t see much present because it is often one of the first forages the cows take out. They will eat it and actually like it, but I certainly wouldn’t plant it.
Summer annual warm-season grasses such as sudangrass or sorghum-sudangrass hybrids and the noted johnsongrass produce a toxic compound when frosted causing the production of the prussic acid (hydrocyanic acid). To be safe, livestock should be removed from these forages after frosted for at least two weeks to allow for the forages to “dry down” and the prussic acid to dissipate before grazing again.
These forages can be harvested for baleage five to seven days after being frosted and later fed as long as they are allowed their normal fermentation process time period of six to eight weeks – but best harvested prior to frost Dry hay containing these is generally fine. Johnsongrass tends to be a bit more toxic than sorghums. Frosted areas could be only “pockets” in a field to start with. Any regrowth from the base of the plant after a frost can also be very high in prussic acid. If in doubt, wait and or test. It is better to be safe than sorry and occurrences can happen with little warning. Millets generally do not have this issue.
Remember, it’s not about maximizing a grazing event, but maximizing a grazing season! Graze crop residues or annuals that you have now to allow pastures to rest and continue to grow until dormant. Keep on grazing!