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  • Going North
  • Prussic Acid Poisoning Potential in Frosted Forages
  • Fall is Time for Change
  • Heat, Drought and Goss's Wilt May Affect Corn Yields
  • Announcements and updates

Going North
By Grant Dewell, ISU Veterinary Diagnostic and Production Animal Medicine
Are you thinking about or have you already expanded your herd by purchasing cattle from drought stricken Texas, Oklahoma or other neighboring states? Although the current low prices may be tempting, there are some animal health and management issues you should consider. These cattle will require a Certificate of Veterinary Inspection (aka Health Certificate) in order to enter Iowa. Cows will need to meet the tuberculosis and brucellosis requirements for Iowa. If purchased cattle originate from non-TB free areas (such as some areas of New Mexico) additional testing may be required. For specific health requirements governing the admission of cattle to Iowa, contact the Animal Industry Bureau www.agriculture.state.ia.us/animalIndustry/cattlelAdmissionRegs.asp

Here is a list of important considerations. More detailed information on each item is available in this article on the IBC website.
  • I would recommend caution when considering purchasing and importing southern cattle into Iowa after the first of October. At a minimum, newly purchased cows should not be co-mingled with resident cows (especially if they are pregnant) for 30 to 60 days.
  • Upon arrival, any cows with signs of disease should be examined by your veterinarian and may need to be culled before it affects resident cows.
  • Because trichomoniasis, a sexually transmitted protozoal disease carried by bulls that causes infertility and early abortions, is more prevalent in some drought stricken states, be especially careful when co-mingling these cows with your resident cow herd. Monitoring pregnancy rates provides valuable information to the producer, and data obtained for 2-3 years after the introduction of new cows is especially helpful to assure that trich or another reproductive limiting disease has not been introduced into your herd.
  • All calves born from purchased cows should be tested for Bovine Viral Diarrhea (BVD) shortly after birth and prior to the next breeding season. Do not co-mingle these purchased cows and their calves with your herd until the calves have been tested for BVD.
  • Many purchased southern cows will be bred to calve this fall, meaning they're approaching or already in the third trimester of gestation. This is when almost 80% of fetal growth occurs. If cows have been nutritionally stressed during this time the calf may be negatively affected.
  • Cattle purchased from drought stricken areas will need time to acclimate to Iowa winters. I would recommend caution when considering purchasing and importing southern cattle into Iowa after the first of October.
Prussic Acid Poisoning Potential in Frosted Forages
By Grant Dewell, ISU Veterinary Diagnostic and Production Animal Medicine and Steve Barnhart, ISU Extension Forage Specialist
The first few frosts of the fall bring the potential for prussic acid poisoning when feeding forages. Some forage species, primarily sorghums and closely related species, contain cyanogenic glucosides, which are converted quickly to prussic acid in freeze-damaged plant tissue. Historically in Iowa there are very few documented cases of prussic acid poisoning. However, the risk is present, and good management practices are necessary to minimize the risks.

Prussic acid, or more precisely, hydrocyanic acid, is a cyanide compound that can kill animals within minutes of ingestion under the right circumstances. Cyanide interferes with the oxygen-carrying function in the blood, causing animals to die of asphyxiation. Symptoms include difficult breathing, excess salivation, staggering, convulsions, and collapse. Affected animals will have bright cherry red mucous membranes from the cyanide. Ruminants are more susceptible than horses or swine because they consume large amounts of forage quickly and the rumen bacteria contribute to the release of the cyanide from consumed plant tissue.

When grazing or greenchopping species with prussic acid potential this fall, follow these guidelines:
  • Do not graze on nights when frost is likely. High levels of the toxic compounds are produced within hours after a frost.
  • Immediately after frost, remove the animals until the grass has dried thoroughly. Generally, the forage will be safe to feed after drying 5 to 6 days.
  • Do not graze wilted plants or plants with young tillers or new regrowth.
  • Don’t allow hungry or stressed animals to graze young growth of species with prussic acid potential.
When making hay or silage from sorghum species this fall, consider the following:
  • Frosted/frozen forage should be safe once baled as dry hay.
  • Waiting 5 to 7 days after a frost to chop frosted forage for silage will limit prussic acid risks greatly.
More detailed information on prussic acid poisoning is available in this article on the IBC website.


Fall is time for change

By Dan Loy, IBC interim director

At the risk of comparing the University to a feedlot, there are similarities that are difficult to ignore.

Like many feedlots, our occupancy increases significantly in the fall. There was a time that incoming students needed to be processed by standing in line, single file, to be signed up for classes, and pay their tuition and fees and other transactions necessary for campus life.

Today, many of these “stressful procedures” are taken care of on-line and well ahead of their arrival on campus.

So parents—no, your children are not “treated like cattle” when they get to college (even though you may have been when you were a student.)

The fact is most cattle are not “treated like cattle” anymore. Pokes and prods have been replaced with flags and paddles in many operations. As evidenced by the attendance at the IBIC BQA seminars on low stress handling techniques presented by Curt Pate earlier this summer, this is something that a lot of people are interested in.

As you look toward weaning calves this fall, also consider getting some of those “stressful procedures” such as vaccinations completed ahead of weaning.

If you are selling your calves after weaning consider putting them through a preconditioning program. In addition to being a good animal care practice, it also can add value to the calves.

Fall is a time of transition for the beef industry.

During the next two months, the majority of the spring born calves will be weaned and marketed, backgrounded or placed in a retained ownership program. Everywhere you look, beef cattle will be on the move and a lot of decisions will be made.

Some of these decisions will affect the success of your beef operation for the upcoming year. Others may be decisions that will impact your operation for years to come.

I've compiled a list of considerations that are especially important this fall.

Read the rest of Dan's column on the IBC website.

Learn how heat, drought and Goss's Wilt can affect your corn yields.

By Steve Ensley, ISU Veterinary Diagnostic and Production Animal Medicine and Alison Robertson, ISU Plant Pathology and Microbiology

Since its initial identification in United States corn fields more than 40 years ago, Goss’s Wilt hasn’t been a serious problem for most Iowa locations. In the past few years, however, the disease has become more common. This year the bacterial disease was identified in Iowa much earlier than in the past, prompting some concern among those whose fields previously had not been affected.

Goss’s Wilt is caused by the bacterium Clavibacter michiganensis subsp. nebraskensis (Cmn) which enters the plant through wounds that can be caused by rain, wind, hail, or insect damage. Drought stressed plants may be more susceptible to such wounds, and subsequent bacterial infection, but Steve Ensley of Iowa State University’s (ISU) Veterinary Diagnostic and Production Animal Medicine department said drought stress presents a much bigger potential problem than Goss’s Wilt for livestock producers.

“Nitrate concentration or cyanide concentration in drought-stressed corn can be a serious threat to livestock use,” Ensley said. “Nitrate is converted to nitrite in the rumen, and nitrite converts blood hemoglobin to methemoglobin, which cannot transport oxygen to body tissues. Cyanide concentration, also known as prussic acid poisoning, works in a similar manner. In both cases, animals often die because of lack of oxygen.”

ISU scientists and others said there are no reported issues with feeding Goss’s-infected corn grain, stalks, or silage to cattle, and there is no scientific evidence supporting harm to cattle caused by this bacterium.

Because the Goss’s Wilt bacteria can overwinter in crop residue for several months, continuous corn acres and low- or no-till fields are at higher risk for developing Goss’s Wilt. In a recent article for ISU’s Integrated Crop Management newsletter, ISU plant pathologist Alison Robertson said there are steps farmers can take to reduce the survival rate of the responsible bacterium in future years.

“Research has shown that pure cultures of the bacterium survive less than two months in soil. However, bacteria found on surface crop residue can survive for at least 10 months,” she said. “Some conservation tillage methods including partially burying infected residue should reduce the survival rates. However, soil conservation measures should always be considered. Also, heat, competition with other microbes and low pH reduce the survivability of the bacterium.”

Announcements and updates

Keep up with Iowa Beef Center/ISU Extension and Outreach beef events.

Bookmark for future reference

Materials from Ida County Beef Facilities Tour now available on IBC website
More than 200 people attended a five-location beef facilities tour and Beef Quality Assurance training in Ida County in late August. Coordinated by ISU Extension, Iowa Beef Center, Coalition to Support Iowa's Farmers and the Ida County Cattlemen's Association, the extended tour included handouts on each of the facilities, information on manure storage and facilities from a variety of agencies, and construction and financial information for attendees.

Links to all five facility factsheets and 12 more publications have been added to the IBC website for your use. See the list on the new "Meeting Information page."

Want to learn more about Goss's Wilt and related topics? Check out the following online resources.