Feeding During Drought

Megan Van Emon, Extension Beef Cattle Specialist

This is a difficult year for all livestock producers, drought, grasshoppers, fire, etc. With these challenges comes the difficulty of feeding livestock not only throughout the summer/fall, but then into winter and the following spring. Feed costs already account for about 70% of annual input costs for livestock producers, and this year will be more due to reduction in feed availability leading to increased cost.

There are options available for livestock producers, but these options are limited to location and availability. This year many producers are relying on grazing of cereal grains for additional feed and considering alternative feeds for fall and winter. The main concerns with feeding these alternatives are amount that can be fed and the potential for nitrates.

Nitrates accumulate in stressed plants, such as in drought, and can cause nitrate toxicity in cattle. Nitrates typically accumulate in the bottom 1/3 of the stem portion, which is a less palatable portion of the plant compared to the heads and leaves. However, when grazing cereal grains or feeding cereal grain hay, a nitrate test should be completed to determine how risky it will be to feed to cattle. Most local Extension Agents have the ability to test for nitrates using the Nitrate Strip Test, which is a quantitative measurement, meaning that an approximate concentration of nitrates in the sample can be provided. Nitrate concentrations will decrease as the plant matures, but once nitrate accumulating plants are cut, nitrates will not dissipate unless they are ensiled. If you are going to graze cereal grains that may contain nitrates, there are a few things to consider.

  1. Turn out cattle later in the day when they are full and not hungry.
  2. If there are high nitrate concentrations, less stocking density should be used so that the field can be grazed lightly and cattle will have the ability to select for the tops and leaves of the plants.
  3. If feeding high nitrate forages, make sure to test the water for nitrate levels as well. Water and forage nitrates are additive, meaning nitrate toxicity could occur even if water nitrate levels are relatively low.
  4. If higher nitrate feeds are fed, provide an additional energy source to the cattle to help with the conversion of nitrate to ammonia. Do NOT feed NPN (non-protein nitrogen) during times of high nitrates. Make sure the protein portion of the feed is all-natural protein.
  5. Monitor cattle closely when feeding nitrate containing feeds. If any adverse effects are observed, remove the cattle immediately from the field and provide non-nitrate containing feeds.
  6. If at all possible, when feeding high nitrate feeds, feed cattle with less risk, such as steers or non-pregnant heifers. High levels of nitrates can cause abortion.

Drought stricken pastures are of low-quality, meaning they have low protein, minerals and energy and high fiber. Feeding a good-quality mineral during drought can help mitigate potential issues at a later date. Minerals are essential to maintaining cattle health and production. Montana pastures on an average have limited concentrations of copper, zinc, and manganese and require mineral supplements. During drought the concentrations of these three trace minerals may be extremely low, which may lead to mineral deficiency if not provided. Minerals are an expensive portion of feed inputs each year and should not be sacrificed to save on these input costs.

Other alternative feeds that may be available are wheat midds, corn, barley, and wheat. All of these feeds are good sources of protein and energy, but care must be taken when feeding. Corn, barley, and wheat are highly digestible in the rumen and could potentially lead to acidosis or bloat if fed at too high level in the diet too quickly. Adapt cattle to grains over a period of time to allow the rumen to adapt to the new feedstuff. Wheat midds are a good source of energy and protein and provide these through digestible fiber and not starch.

Straw can be fed to cattle as long as a good-quality forage is fed with it, this will minimize compaction issues. Straw in mature cows can be fed up to 50% of the diet until the 3rd trimester and then straw should be limited to 25% of the diet. Straw should be limited during the 3rd trimester due to rumen capacity limitations and the increase in requirements. Straw should not be fed during lactation due to the large increase in nutrient requirements. Straw can also be fed to first-calf heifers at 25% of the diet until the 3rd trimester. Straw is not recommended during the 3rd trimester and lactation for first-calf heifers. Feeding straw can help stretch limited hay supplies. We can work together to create a good mix of straw and good-quality hay to prolong the use of higher quality hay.


This year is going to be a tough year when feeding livestock and many different feeding strategies will be employed. We can work together to develop feeding strategies that will work for your operation.