NC State Extension

Animal Health: After the Storm

Originally published in December 2016 Carolina Cattle Connection

I understand that the timeliness of this article may seem heavily delayed and not widely applicable across the distribution area of this magazine. By the time this is published, I certainly hope that most producers have recovered physically from the floods Matthew brought to our area. The emotional and financial effects certainly may be more long-term. Regardless, I think the topic is worthy of exploration, and is one that we should all be prepared in the future. The effects of flooding on beef animal health are diverse, and can be immediate or more protracted and insidious.

The immediate effects of flooding are obvious and devastating. Direct losses due to flood waters would include drownings and electrocutions. Youngstock, especially just-born calves, would more likely be taken by fast-moving flood waters. However, reports out of Louisiana following Hurricane Katrina demonstrated the power of massive flooding: entire herds of beef cattle were simply washed away in the devastating 2005 storm. We are fortunate that the flooding that occurred in southeastern NC and SC in October did not present this kind of challenge on a large scale to our states’ producers.

In the event of such losses, clean-up becomes a major issue. Landfills may close their gates to livestock producers needing to dispose of carcasses in anticipation of large amounts of construction debris entering the facilities, as well as due to disruption in regular municipal waste delivery which would normally be used to cover carcasses. In North Carolina, livestock producers are required to dispose of dead animals within 24 hours of known mortality either at an appropriate disposal sites or direct burial on the owner’s property. In mass mortality events, your best option is to contact local officials who know the laws and exemptions particular to these regulations following a storm and work closely with them to protect your operation and the local environment. Carcasses pose a direct hazard to remaining animals in the herd, as well as potential hazards to your neighbors and people downstream if not disposed of in a timely and appropriate manner.

After floodwaters have receded, your animals are not clear of any and all dangers to their health. Damaged feedstuffs and pastures can potentially harbor pathogens or toxins spread or brought in by floodwaters. These agents can be immediately deleterious to animal health and well-being, or cause issues to develop in the days, weeks, or months following the storm.

Bacterial pathogens of concern would be Clostridial organisms (such as C. perfringens, C. botulinum, or C. novyi), Salmonella species, or E. coli. Clostridial organisms can cause a variety of disease syndromes, depending on the type you are dealing with. Clostridial diseases can present as sudden death, diarrhea, sepsis, or down/weak animals. Any age animal, especially if unvaccinated, could be lost if fed contaminated feed or forage. Salmonella is an enteric bacterium normally harbored in the intestines of livestock, but can cause severe illness in stressed cattle or when exposure levels are higher than normal. Signs of illness would generally include severe watery to bloody diarrhea, down/weak animals, and quick progression to death. This pathogen poses a direct threat to human health as well, and could be transferred from a sick cow or calf to their caretaker. E. coli would be similar to Salmonella, but much more detrimental to the health of young to very young calves. This pathogen would be another example of a pathogen that is dangerous to people exposed to an animal that has picked it up. Any animal that dies unexpectedly following a rapid onset illness or is found dead in the pasture following a natural disaster should be examined by a veterinarian as close to death as possible. If one of these pathogens were diagnosed on exam of a sick animal or at necropsy, control and mitigation plans should be implemented to protect the remaining herd members.

Toxins of concern would include heavy metals (cadmium, mercury, lead, etc.), organophosphate pesticides, chlorinated hydrocarbon pesticides, and PCBs (polychlorinated biphenols). These agents can cause illnesses in cattle, but more importantly, present residue potentials in the tissues of animals that may be moved to harvest. Testing of pastures (soil and/or forage tests) as well as testing of harvested feeds that were exposed to floodwaters is highly recommended to ensure that you are preserving the quality and safety of the food products supplied to the public. NCDA is working diligently to assist farmers with these procedures and I would encourage all reading this article that experienced flooding on your operation to work with your herd veterinarian and local extension agents to get this important testing done. Beyond those directly affected by Hurricane Matthew, hay resources will likely be strained in parts of our state as there could be significant quantities of hay that, following testing, will have to be destroyed. Identifying marketing channels to get hay into affected areas will be important for preserving animal health and positively impact the NC cattle industry. Similarly, making sure that hay being brought into your operation is not adulterated will be very important after this historic flooding. Ensuring that you are working with reputable hay providers is key to protecting our industry.

Some toxins will not be brought in by the floodwater itself. Rather, the flood damaged feed will develop toxic levels of mycotoxins after they been soaked and unable to dry out. Some examples of mycotoxins that are dangerous for beef cattle are ochratoxin, vomitoxin, zearalenone, D2, fumonasin, and aflatoxin. Much like bacterial pathogens, the exact clinical symptoms you may see after feeding toxic hay depends on the levels of individual toxins. Common signs are poor body condition, various illnesses (poor immune function), poor fertility, and death. It is common for improperly cured or stored hay or grains to develop dangerous levels of these toxins, but certainly feeds that were exposed to floodwater are at an elevated risk of becoming toxic to cattle consuming them. Performing mycotoxin screening of all stored feeds is a good idea. A “wait and see” approach to feeding flood damaged feedstuffs can be very expensive and potentially very detrimental to the health and well-being of your cattle.

Of particular concern going forward will be the long term effects of flooding on cattle management systems. Animals that have gone through a stressful event such as a natural disaster often have subclinical effects that can take time to manifest. Prolonged deprivation of mineral or other nutrients can lead to altered blood levels of said nutrients. It is sometimes hard to recognize the subtle effects of altered nutrient levels in the blood, unless the nutrient is tightly controlled within a tight range. An example of this would be magnesium where dropping below a certain level leads to immediate illness. Other nutrient deficiencies may not be so dramatically displayed. Clinical manifestations of nutrient deprivation depend on the demands on the cow’s system: if demands are not tremendous and her body stores are adequate, she may not show too much outward trouble. But if demands change (calving, lactation, etc.) the cow would go down or die quickly if not identified and addressed quickly. Of particular concern in the face of damaged and unusable stored feeds, the potential for energy-protein malnutrition is great following natural disasters. The carrying capacity of stockpiled pastures can be severely decreased by the effects of floodwaters, and the nutrition levels provided by remaining grasses may or may not meet the needs of the animals grazing them. Body condition scoring is the easiest and most basic evaluation technique available to producers, and should be performed regularly in the course of herd management. This management tool is of critical importance in the aftermath of a natural disaster. Producers should watch cow condition and calf growth rates closely to ensure cattle are maintaining appropriate on available forage. Comparing cow condition over fixed time-points and cross-referencing to stage of production is vital for the data to be useful. Supplementation will be costly up-front, but should balance out if production levels can be maintained in face of pasture deprivation. Actions to correct declining condition should be implemented as soon as a problem is identified. However, the response should be based on sound objective analysis of available resources. Working with an unbiased source of information is critical to protect your operation. Knowledgeable veterinarians, extension specialists, and nutritionists can certainly fit these qualifications. Most often, energy supplementation will be most critical through the winter, but protein availability may also present an issue this feeding season.

Cattle management following a natural disaster is complex and could be the cause of much anxiety through this year’s feeding season. Preparing your operation to “weather the storm” after the storm relies on your ability to engage knowledgeable professionals as well as to mitigate your risk through feed analysis and forward planning of farm resources. The task is not overly difficult to accomplish, but will require brain time. In the face of declining markets, it may seem impractical to spend more on the feeding season than you normally would. I challenge you to consider the cost of a herd health train wreck and compare that to the cost of being proactive and preventing said secondary disaster.