FEED RELATED DISEASES by Mike Mehren Ph.D.

FEED RELATED DISEASES
by Mike Mehren

Thanks to friends and clients who’ve asked some great questions recently, I have something to write about. I should list them as co-authors, but I won’t! This column will be a discussion about feed-related diseases and a parasite that takes advantage of calves when they are weaned or stressed. Coccidia are a parasite that lives in the intestines of cattle. It is present in almost all cattle, but that doesn’t mean that all cattle have the disease. There is evidence that coccidia affect immunity, and cattle that are heavily parasitized are more susceptible to other stress-related diseases.

The disease most often appears in calves, however it can appear in any age animal. Stress leads to the onset of this disease. It is usually seen as ‘bloody scours’. Following the scours, animals will go off feed and become dehydrated. Diagnosis should be made by your Veterinarian, because treatment for other agents that cause scours will not be effective against cocci. Unfortunately this organism adapts extremely well to almost any environment. It can withstand extreme heat and bone-chilling cold. Once cattle have had the disease, the ground that they were on will be contaminated forever!

There are feed additives available to treat or prevent coccidiosis. A treatment can also be provided in the water. The only feed additive that is approved for treatment is Corid.
This happens to be the same compound that is added to water.

Treatment: Corid is available for mixing into a protein, or grain or mineral supplement, and as a crumble. It is fed for 5 days. It requires a 24-hour withdrawal prior to slaughter. The biggest challenge is to make sure all of the animals eat the required amount each day. If the calves are sick and not eating, it becomes almost impossible. It is best used immediately after a couple of calves are diagnosed. Those calves are treated with antibiotics and their pen-mates receive the Corid treatment.

There are several feed additives that are approved for the Prevention of coccidiosis.

Corid. Once again, this can be mixed into a grain mix, mineral, supplement, or provided as a crumble to top-dress on hay or a mixed ration. It is fed for 21 days. Do not stop after two weeks, as the life cycle of the cocci has not been broken for all those that are developing inside the animal’s body. Once again, remember that there is a 24 hr. withdrawal prior to slaughter.

Bovatec. This is feed additive that you might be familiar with because it improves weight gain and feed efficiency. It can also be used to prevent cocci.
This additive is used for Control (prevention) only. It requires 200 milligrams per head daily to serve this function. There is no feed withdrawal prior to slaughter. Bovatec can be mixed into a mineral, grain mix, or supplement (liquid, cube, Or meal). Normally this additive is fed continuously, rather than for a short period of time.

Deccox is a feed additive that is cleared only as a Prevention for coccidiosis for calves. It can be mixed into a mineral, grain mix, supplement, or is available as a crumble for topdressing. Deccox is supposed to be fed for 28 days. Many times it is added to a receiving or starting ration after calves are weaned or when they are shipped to a feedlot.

Rumensin is cleared for improved feed efficiency and rate of gain as well as Prevention of coccidiosis. It can be mixed into a grain mix or supplement. For some reason cattle will not consume enough of a 1 to 4 oz mineral to be effective. However, if the mineral is designed for 6 oz intake or more, cattle will eat it as well as other products. Rumensin does not have a feed withdrawal time prior to slaughter. A dose of 60 milligrams or more daily is sufficient for cocci control. One benefit that this additive has as opposed to the others, is that it can be fed to the cowherd prior to calving. It does several things when used that way: (1) it improves the utilization of the feed, which means that you can feed 5 to 7% less feed and still maintain body condition, and (2) it dramatically lowers the coccidia that are resident in the intestines of the cow. This means that there is less chance for the calves to become infected with coccidia.

One of the biggest things that you can do to prevent coccidiosis outbreaks is to calve on clean ground. Using an additive that prevents coccidiosis will help, but if the cows are forced to calve in a dirty, muddy pen, your calves may still come down with the disease.

I’ve also had quite a few calls about nitrates. We are using a wide variety of feeds that may not have been fed to cows before. Nitrates can come from two sources (1) Water, and (2) feeds . Feeds that have been identified include the following:
Pigweed, lambsquarter, oats, sudangrass, sorghum/sudan crosses, barley,corn, wheat, kochia, pigweed, nightshade, fescue, morning glory, and rye. I recently read where some folks are advocating beef cattle for weed control; make certain that the weeds aren’t toxic before you try this!.

Testing for nitrate concentration in plant tissue costs about $10.00. Virtually all feed testing labs run this analysis. Results are available the following day. This is quite fast and a lot cheaper than trying to treat cattle or lose them. If water contains
more than 100 ppm of NO3, it could be dangerous. In feed, unfortunately nitrates are reported several different ways. This table should help to determine if your feed might be toxic.

Reported Form of Nitrate	Percent	Parts Per Million (ppm)
	…..100% dry Matter……
Nitrate Ion (NO3)	0.9	9000
Nitrate Nitrogen (N03 N)	0.2	2000
Potassium Nitrate (KNO3)	1.5	15000

Water nitrate and feed nitrate make up total nitrate intake. Each by itself might not be toxic; but when combined can be toxic. Fortunately, cattle adapt to nitrates just like they do to urea. A high nitrate feed that would be toxic can be blended with a feed having of the feed can be increased slowly until it can be the sole source of feed. A period of three weeks should suffice in making this change.

Symptoms of nitrate poisoning include breathing distress, incoordination, weakness, muscle tremors, frothing, and pale mucous membranes. Moving or stressing the animals may bring on the symptoms. Nitrates have also been shown to cause abortion, breeding failure, and susceptibility to infection. During nitrate poisoning, the blood appears ‘chocolate’ rather than red. In an emergency, you can dose the animal with a gallon of vinegar and then call your Veterinarian for proper treatment of nitrate poisoning.

The final challengers to good health for this article are molds, yeast, and fungi. The more we learn about them, the more they should be watched for and avoided. I know the temptation is great when feed is so high priced. It’s just a little white mold, black mold, green mold, or grey mold. It smells musty, but the cows still eat it. It may be the black layer on the outer edge of silage. However, under the right set of circumstances these organisms can cause death and abortion. At the very least, they suppress the immunity of the animals!

In this group are the endophytes that are present in some fescue and ryegrass straw and ergot that infests grain and grain hay. The endophytes fungus cannot be seen, but can be detected in a lab. Oregon State Univ. Endophyte Svc. Lab performs that analysis for us in the Pacific Northwest. They can be contacted at 541-737-2872. They are also able to test for ergot. There is at least one firm in the Northwest that is marketing grass seed straw that has been pre-tested for endophytes. Their name is K&L Farms, of Umatilla, OR.

We now have several excellent products on the market to protect cattle from the toxic effects of mold, yeast, and fungus. If you absolutely must feed something that you know is infested, consider adding a mold inhibitor, or binder to your supplement. These products can be added to liquids, pellets, cubes, blocks, or meals.

These questions have convinced me that more cattlemen and women are planning ahead to prevent problems, rather than calling when the wreck has occurred. They definitely recognize that money spent in prevention, especially during hard financial times, can make a huge difference in survival.

Mehren’s politically incorrect dictionary defines Political Science as an oxymoron.

Michael J. Mehren, Ph.D. is a livestock nutritionist who has forgotten where he lives. If you see him report his whereabouts to: mehrens@eotnet.net.