Typical death loss rates (also known as mortality) are 2 to 3 percent and, in some cases, even higher. These producers know there is a certain risk dealing with these types of animals because they are stressed, immunocompromised or have been injured during the marketing and transportation process.

It is regrettable and, while everyone works to minimize this issue as much as possible, it is a fact of life.

But what about the mature cow? Unfortunately, from time to time producers will lose what was, for all practical purposes, a big, strong, healthy cow. So then what?

Questions, questions

When the producer discovers a cow that has died, a whole variety of questions comes into play:

1. What was the cause of death?

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2. Did the cow have a calf that now needs to be cared for or dealt with?

3. Is that cow the only one?

4. Is there a possibility more can be lost?

5. What should be done now?

One loss is bad enough. If there is the potential for more losses because the cause is either health-related and transmittable, or if the cow ate something toxic the others might also consume, there needs to be immediate action to prevent further losses.

Cause of death

Often identifying the cause of death is simple to answer. The cow may have had trouble while calving in an area where no one was checking on heavily pregnant cows regularly. Some causes are more difficult to diagnose.

If it was from disease of some type, having a veterinarian post (autopsy) the animal and take samples, which are then sent off to a diagnostic laboratory, is the only way to determine what the condition or disease might have been. It can also help show where the “holes” are in the farm’s animal health or vaccination program.

Another possibility is the ingestion of a toxic substance like lead from old car batteries or toxic plants. Consumption of high amounts of acorns (not uncommon in pastures where oak trees are plentiful or forage is short) can be fatal.

Grazing pastures high in nitrates (normally greater than 1 percent nitrate) or prussic acid (sorghum-type forages that have been cold- or drought-stressed) can be very toxic.

Grazing winter pastures such as wheat, oats or ryegrass, if the cows are not prepared or if proper supplements (high-magnesium minerals or similar) are not fed, can lead to grass tetany or even hypocalcemia/milk fever.

These conditions can be difficult to diagnose without extensive analyses. Grazing clover pastures can lead to bloating, which can also be fatal if not treated properly. Again, this is a fairly obvious condition.

Consumption of feeds and feed supplements can lead to animal death. This generally occurs if the management of a given supplement is not correct. One of the most common causes of animal loss is urea poisoning (ammonia toxicity).

This can occur when a cow consumes an excessive amount of urea in a short period of time. This most commonly occurs when hungry cows are allowed free access to feeds or supplements high in urea. This may be found in dry feeds, tub supplements or liquid feeds.

Urea inclusion as a source of nitrogen (which the rumen bacteria convert to protein) is very common. It is a safe practice, but producers must take care as to how these supplements are fed and excessive consumption is prevented. Again, this is not always easily diagnosed without a proper autopsy.

Another example is sulfur toxicity from consuming feeds and forages high in sulfur. Excessive sulfur in the animal’s diet interrupts the bacteria in the rumen from producing the B vitamin thiamin. The thiamin deficiency results in a neurological condition known as polioencephamolacia. Again, this is a condition that can occur when consuming an overall diet for a period of time where the total sulfur is excessive.

Getting the vet involved

If a producer really doesn’t know what the cause of death was, the producer has to ask a few more questions. Initially, the producer must decide if veterinarian involvement is wanted or needed, along with the added cost.

If the cause of the loss is obvious (cow lying bloated in a clover pasture, etc.), then no further action may be necessary other than to dispose of the carcass and take steps to ensure it does not happen again. If there is a possibility it could affect other animals, then yes, the vet needs to be called. One of the first things to determine before having the vet out is how long the cow may have been dead.

If it has only been a few hours, then your vet can effectively post the cow, take tissue samples and send these off for analyses. If she has been gone a day or more, the accuracy of autopsy or samples taken may be limited.

Remember, if the cause is not reasonably obvious, there is always a potential risk to other animals in the herd. Your vet needs to determine if the cause was health-related (related to a pathogenic organism) or nutritionally related (consumption of something that led to the animal’s death or toxicological consumption of a toxic substance of some type).

There are screens/panels of tests including rumen contents, blood/serum enzymes and mineral values, all of which are indicative of one problem or another.

Furthermore, a close examination of the pasture or area the cow had immediate access to must be made. It is helpful to become familiar with toxic plants native to the area. Problems of this nature generally do not occur unless forages are in short supply.

Finally, taking the time to think through how that animal was managed, the pastures it was on and what it was fed are important. In many cases, this can reveal that management may have played a significant role in the cow’s loss and steps can be taken to avoid these practices in the future.

Costs

Diagnosis of a cause of death can be expensive. The vet exam/post followed by lab analyses can run into the hundreds of dollars. Because of this cost, it is critical this process is handled correctly and objectively. Sampling, shipment and analyses of feed and forage samples can also be expensive.

It is a good idea to contact your veterinarian preemptively and discuss these situations. Determine what their normal charges are for a farm call, posting, sampling, shipment to the diagnostic lab, etc.

A discussion concerning how your vet handles these situations is important since proper diagnosis can direct how the producer needs to handle potential changes in the health program, grazing practices, supplements fed and general management.

The same goes for the costs involving samples sent to a feed and forage lab. Locating a qualified lab as well as one that may deal with unique situations can save time and headache. Also, using a lab that can turn samples around quickly is important.

A trained, experienced nutritionist can help you interpret reports. This information should be considered in combination with the diagnostic lab reports. The goal is a quick, accurate diagnosis.

It makes sense to have a plan in place should losses of this nature occur. Hopefully, it will not happen with any regularity but, when it does, a protocol involving your veterinarian, nutritionist, possibly extension personnel, anyone who can provide helpful and experienced input, is valuable in determining the cause of the loss.  end mark

Dr. Steve Blezinger is a nutritional and management consultant with an office in Sulphur Springs, Texas. He can be reached by phone at (903) 352-3475.

Stephen Blezinger