Summer 2000



Dealing with Drought

You are in a devastating drought; you see it every day in every field or pasture you drive in. The question though, is what should you do to get through it? As a livestock manager you will have to make some tough choices as to what to do this year. My suggestions are to reduce the stocking rate, target feed and minimize pasture stress as much as possible.

Reducing the Stocking Rate

Nobody likes to reduce their herd size when calf prices are high, but this is the most economical way to survive a drought. You can expect cow prices to decline as more people sell cattle, so I would suggest doing it soon. Don’t wait until your grass and hay are gone to sell cows. Do it now to conserve what is left. Start with any cow that does not have a calf or is not pregnant. Pregnancy test every cow and get rid of the cattle that will not pay dividends in the coming year. I would also consider early weaning. Cows will lose less weight if they are not feeding a calf and will be more likely to get pregnant if the bulls are still out. Next, sell those older cows over 10 that are having lighter calves each year. Unless you have a feed source for them replacement heifers will be difficult to develop without adequate pastures and will not pay any dividends in the coming year.

Keep the cows that are less affected by nutritional stress. First and second calf heifers will have a difficult time getting pregnant under normal conditions and will be much more likely to be open during a drought. These should be your best genetics, but open cows don’t pay the bills. Once you have culled your older and younger cattle in poor condition you will be left with a your most productive cows in that 4-10 year old range. At lower body condition scores (BCS 3 and 4) those middle aged cows will average 35% higher conception rates than first calf heifers and 20% higher than second calf heifers.

Basically, the best way to get through this year will be to reduce the herd to cattle that can produce income this year so that we can stretch our forages and feed budgets until we have abundant grass again. Don’t get caught in the trap of just selling a few cows to buy more feed. You will end up with only a few cows and higher losses. Cut your losses now because even if it rains tomorrow more than likely there will not be adequate grass to carry the whole herd this fall.

Don’t wait until your grass and hay are gone to sell cows. Do it now to conserve what is left.

Target Feeding

With the cows you keep you need to have enough hay to carry them for another 30-45 days. If you have a little hay left over you can always feed it first later this fall. If you are low or out of hay, locate some now. If this drought keeps up for another month, hay will get much harder to find. There is a list of producers at the Extension Office that have hay for sale. Dry cows can normally maintain their weight on average quality hay (7% protein and 48 % TDN), but lactating cows need a protein and energy supplement in addition. That’s why early weaning may be the best solution.

If you do decide to hang on to some of your calves, I would suggest developing a feeding program that targets their needs. Creep feeding can keep calves gaining and provide the higher plain of nutrition that growing animals need. Generally, hay does not have enough protein and energy to keep calves gaining weight. Certainly a protein feed like cottonseed meal will provide a needed boost during most summers when there is adequate grass, but if the only available forage is hay, then energy will be needed as well.

Buying bulk commodity feeds is the cheapest feed source if you have the facilities to handle them. You don’t have to have a grain bin. A dry concrete floor of a barn can be used to handle bulk feeds on a temporary basis. Wheat middlings provide a good source of both protein and energy. They average around 18% protein and 83% TDN. Soybean hulls are are excellent energy source of energy but may not supply enough protein in a limit fed creep feeder. They run somewhere around 12% protein and 64% TDN. Corn and oats are excellent energy sources but they are not digested in the rumen, which can limit hay intake if high levels are fed. The key is to target your needs so that you spend your money wisely.

Minimizing Pasture Stress

Certainly you don’t want to do anything to your pastures that will cause a loss of soil moisture or add stress to grasses. Aerating, disking and herbiciding should be delayed until pastures are healthy again. You definitely don’t want to plant anything until we have significant rainfall. Even if you are feeding hay, you still want to rotate cattle to different pastures to prevent over grazing and damage caused by constant feeding. Rotate your cattle slowly to keep the grass as healthy as possible. Fast rotation on slow growing grass will hurt the grass more than leaving them on pastures longer. Also, you need to keep an eye out for poisonous plants. Cattle will not normally eat poisonous weeds, but when there is limited grass they will try to fill their bellies with whatever is green.

The main point is to make a plan of action if you have not already done so. The effects of this drought will be with us well into the fall, so we need to start preparing for it now.

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Nitrate Poisoning from Drought Stressed Corn

If you have been considering making feed out of your corn, you should test it to make sure that nitrate levels are acceptable. Corn and Sorghum can be toxic to cattle if nitrate levels get to high in the stalks. There is a simple field test that can identify moderate to high levels of nitrates. Once nitrates are found then the corn should be sent to a lab and tested for exact levels. Sorghum also develops prussic acid during a drought and this too can be toxic to cattle. However, the greatest danger with prussic acid is when the plants are grazed.

High rates of nitrogen fertilization in combination with drought conditions often cause plants to accumulate high levels of nitrates in the stalk. High temperatures, large losses of leaves, failed pollination, low phosphate absorption and limited water intake can create conditions trapping nitrates in the stalk below the ear shoot. Because the plant is unable to grow, these plants have the highest levels of nitrates at the base of the stalk. If no ear is formed or if ears cannot be pollinated, these plants will accumulate large stores of nitrates.

A simple field test can tell if nitrate levels in drought stressed corn are high enough for further testing.

This corn can be utilized as feed with caution if the levels of nitrate are known and can be diluted with other feeds. Making silage also helps to reduce nitrates by up to 40% if allowed to ferment for at least 21 days. If ample rainfall is received the corn will return to normal levels, but it may take 7-14 days. If the corn is killed by drought, then there is no way for the trapped nitrates to escape.

Plants that often accumulate nitrates under drought conditions include field crops, weeds, vegetables forage and grain sorghums and especially corn. The symptoms of nitrate poisoning include staggering, muscle tremors, rapid pulse and urination, labored breathing, blueing of the mucus membranes and abortions. Cattle die from low oxygen levels in the blood. The blood of dead cattle will be chocolate brown in color. One cure for Nitrate poisoning is early intravenous injection methylene blue. If you are considering feeding drought stressed corn or sorghum to cattle, contact the Extension Office for more information.

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