Grazing Through a Drought

By Janet McNally

This article first appeared in the August-September 2023 issue of Graze. We're sharing it here in full to give you a taste of the practical content we offer in each issue of the magazine. For the full meal, subscribe today!

Here we are in our third year of reaching D1 and D2 (moderate to severe drought) status, some nine inches below normal on rainfall from mid-April to mid-July.

A different drought

Yet even though the basic summer weather pattern was similar, this year’s drought is different from last year’s. What’s different is that our spring moisture came almost entirely from the 90 inches of snow we had last winter, with very little from rain.

As a result, first-crop forage growth was not quite as rank as it was last year, making for a little more energy in the grass even as it dries out at mid-summer. We also seem to have abundant thistles on some parts of the farm. As of this writing I am still getting regrowth after grazing, but it is very slow.

Under the right conditions, lambs can fatten easier in a drought.

Keeping the ground covered is paramount for keeping the soil cool and preserving what moisture we have, so I continue mob-stock grazing, keeping paddock sizes small enough to get effective trampling of unpalatable forages. The new twist is that due to the thistles and the fact it appears our regrowth is going to be very limited until we do get rain, during July I am mowing behind the sheep in pastures with thistles.

Besides controlling thistles, mowing the grass stems will promote vegetative forage regrowth. I am setting the mower high, as this helps provide a buffer between the mowed residue and the soil. Mowing too close will dry out the soil.

I did not mow behind the sheep in June, as they did a good job in cleaning up thistles and trampling the grass stems when the plants were tender.

Last year I started feeding a protein supplement at this point because the forages were more rank (more stem, less leaf) due to early spring rains and very rapid growth. So far this year it appears we have more leafy material, as the drought limited stem growth.

The ewes are holding their body condition fairly well and the lambs are fat, so for now I am holding off on mowing the paddocks with fewer thistles. As of this week I am on my second round of grazing, which should improve the level of nutrition available to the flock.

Years ago the NRCS forecast longer dry spells followed by heavier rains in the Great Lakes region, so unfortunately this may be our new normal. It is more important to pay attention to residual and rest when grazing in dry weather, as the soil is less forgiving.

Keeping in mind that each dry year can be different, here is some general advice for grazing through a drought:

1. The first rule in a drought is to reduce livestock numbers. Cull deeply and, if necessary, sell before you run out of feed. If you wait until it is obvious that pasture is short, you will be selling at the same time as everyone else, and prices will be depressed. So sell while the selling is good.

2. Do not try to feed your way out of a drought. It just won’t work. This year is a good case in point, as this is our third year of drought and those who chose to feed their way through the droughts became unprofitable two years ago. Feeding through this one will be no different. It’s OK to purchase protein, hay or grain as supplements to pasture; I’m talking about not purchasing hay or grain to replace pasture that didn’t grow in a drought. If you are having to feed lots of hay at midsummer, your stocking rate is too high.

3. Do feed protein if needed, as protein content declines when pasture plants go brown and dormant. A little protein can go a long way toward helping improve the digestibility of dormant forages. How much depends upon the protein content of the forages as shown by a forage test. Some ration balancing will be required. (See the accompanying article for how to take a pasture sample.)

4. Keep the ground covered at all times. Covered soil can be as much as 30 degrees cooler than uncovered soil, and covered soil does not dry out as fast. If you put your hand under the residue, you will be surprised by the moist microenvironment. More important, covered soil preserves the soil microbiome. Paddock size and grazing duration will determine how much stem material is trampled to provide cover.

5. Be mindful of the length of rest periods between grazing events. In normal times I want at least a six-week rest period, and the first round of grazing often ends up allowing an eight-week rest before the second grazing. Catching up to my first paddock in only five weeks is a sign I have too many livestock on hand. One nice thing about daily moves and long rest periods is that you have about five to six weeks of warning that you are going to run short of grass.

6. If you do run out of grass and cannot maintain enough residual, do not just leave the livestock out there to grub what’s left. Honor the rest period and let the pastures recover. If you do not want to destock and must feed hay, move them to a yard or sacrifice area, but do not pummel the pastures.

Too often people just start feeding hay on pasture residue. The result is dwindling root reserves. When the rain finally comes, the grass will not have enough root reserves to recover quickly.

7. Wean early and save what little green forage you have for the lambs. What is early? For lambs born and reared on pasture, 80 days is probably the earliest you should wean. If you wean earlier, a grain supplement may be in order and should be started before weaning.

Once weaned, ewes are very portable and can be used to clean up neighboring projects. Knock on doors! Most people should be able to find abundant feed for dry ewes somewhere in the neighborhood. Compare the cost of some portable fencing to hay, and you will probably find that the fencing is a good investment.

8. Be aware that should wet weather return after a drought, it is possible that dormant parasite eggs will hatch en masse, creating a heavy parasite load two or three weeks later. Avoiding heavily soiled paddocks for six weeks after the rain will reduce the risk.

9. One upside: A dry year can give the forages a bit more kick, so finishing lambs is easier than in a wet year.

Janet McNally grazes sheep near Hinckley, Minnesota.

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