Supplementing Cattle on Drought-affected Pastures

Submitted by Eve H. Honeycutt, Livestock Agent, Lenoir and Greene Counties

 Adapted from an article by Greg Lardy, Extension Beef Specialist, Department of Animal and Range Sciences, North Dakota State University

As I write this, it is too early to tell if the recent rain will do enough to improve the effects of the recent dry, hot weather on our forage crops.  With any luck, there will be more rain in the near future to increase soil moisture and forage yield.  But just in case, I thought some good information about drought affected pastures would benefit those of you with grazing animals.  Cattle producers generally have two main options for meeting the nutrient requirements of cattle on drought affected pastures and ranges. The first is to provide supplemental feed to ensure the cow herd has adequate energy, protein, vitamins, and minerals. The second is to reduce the nutrient requirements of the cow to a point where they can be met with available forage.

Drought-affected pastures generally do not produce adequate forage to maintain "normal" stocking rates, so producers must provide supplemental energy to meet the needs of the cow herd. Pastures that are dormant due to drought conditions may be low in vitamin A, phosphorus, and protein.  Meeting the need for these nutrients is important if cow herd productivity is to be maintained.  Reductions in stocking rate will benefit plants by reducing stress and will also provide more forage for the remaining cattle. When stocking rates are reduced in accordance with production, only small effects on weaning weight may be noted.

Providing Supplemental Feeds During a Drought

Minerals. Provide the same salt and mineral mixture during drought as you would during normal conditions. However, during drought phosphorus supplementation is critical.  A mixture of 50 percent trace mineralized salt and 50 percent dicalcium phosphate supplied free choice to the cow herd will meet the phosphorus requirement. The salt mixture should be placed close to stock watering locations.

Vitamin A. Lack of vitamin A may be a problem during fall and winter for cows that grazed drought-affected pastures during summer. Vitamin A is lacking in forages during drought and hay produced from drought-affected forages. Cows should receive vitamin A and D booster shots approximately 30 days prior to calving and their calves should receive vitamin A and D at birth.

Protein. Pastures dormant due to drought conditions may be deficient in protein. If these conditions occur during the breeding season, reductions in pregnancy rate can occur. Provide dry cows with approximately 0.5 to 0.75 pounds of supplemental crude protein and lactating cows with 0.9 to 1.2 pounds of supplemental crude protein per day. This can be fed as approximately 1 to 1.5 pounds of soybean meal for dry cows and 2 to 2.5 pounds of soybean meal for lactating cows. Protein supplementation may be necessary for optimum breeding rates during drought conditions. Alfalfa hay, sunflower meal, safflower meal, as well as other protein meals may also be used as protein supplements.

Energy. Since forage production is generally limited during a drought, energy may be the most limiting nutrient for grazing cattle. Several options are available for supplying energy to cattle on drought-stressed pasture. Hay, grain, and crop processing byproducts can all be used to supply energy to grazing cattle.

Grain processing coproducts, such as wheat midds, soyhulls, barley malt sprouts, beet pulp, and corn gluten feed, which contain highly digestible fiber provide energy while alleviating much of the negative impact that grain supplementation has on fiber digestibility. In addition, these byproducts provide protein which may also be limiting in drought-stressed forages.

Drylot Feeding. If pasture conditions are extremely poor, producers may consider feeding cows in drylot. This may be more cost effective than supplementation if large amounts of supplement must be transported and fed to cows daily. In addition, it may allow pastures a much needed rest period to begin recovering from the drought.