Extension Outreach Response to Livestock Mortality Events Associated With Algal Toxin Production in Georgia Farm Ponds

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Purpose

Excessive nutrient enrichment in watersheds can create harmful algal blooms (HABs) in aquatic systems, including ponds, which are frequently used to water livestock. Harmful algal blooms are typically dominated by cyanobacteria (commonly referred to as “blue green algae”) many of which produce toxins that can be harmful to fish, wildlife and humans.  In May 2012, our laboratory began receiving reports of cattle mortalities associated with HABs. We began an outreach effort to screen and identify algal species and toxins in water samples submitted by private citizens from ponds throughtout Georgia. Prior to this effort, no state or federal laboratories offered such a service. Private laboratories conduct these services, however the collection protocols and analytical costs preclude the average citizen from utilizing them. Rapid detetion of a HAB is critical for farmers so that access to the water source can be restricted. We recognized the need to provide such a service and to educate the public regarding exposure effects, preventative measures, and treatment of HABs.

During Summer 2012 sampling events we commonly encountered Microcystis blooms in both farm ponds used by humans for fishing and recreation (above) and for watering livestock (below).

What Did We Do?

We documented dense blooms of  planktonic cyanobacteria, predominantly Microcystis aeruginosa, and  extremely high levels of the potent hepatotoxin, Microcystin, in water samples submitted by Georgia cattle producers (Haynie et al. 2013). Many of these samples were submitted by producers who had experienced cattle mortalities, potentially due to algal toxin exposure.

Through a collaborative effort with UGA’s Agriculture and Environmental Services Laboratories, we established a water screening service that includes algal speciation and toxin detection. This service became available to the public in Februrary 2013. This effort included a detailed outreach letter to extension agents, sampling protocol and materials for water sample collection and shipping. This screening service is avalible for either a $30.00 (algal identification) or $45.00 (toxin analysis and algal identification) fee. The submitter will receive an electronic report within 24 hours with results, interpretation, and recommendations.

We have begun promoting this service and educating the public about HABs by participating in various short courses, meetings and outreach opportunities.

What Have We Learned?

We have demonstrated that HABs and cyanotoxins are common in Georgia agriculture ponds. Therefore, the potential for livestock exposure and subsequent effects including mortality are likely to occur. Education and establishment of a rapid toxin detection service is warranted and will be beneficial to producers. The livestock deaths have highlighted an important issue for Georgia farmers and pond owners that will likely be increasingly prevalent under projected climatic models.

Future Plans

We will continue our outreach efforts by participating in University and industry sponsored workshops and meetings. We will use these opportunities to educate and inform the public about the newly available algal screening service. We have included, in recently submitted grants, funding to subsidize testing expenses in order to encourage more farmers/pond owners to use this service. We intend to utilize the testing service to gather spatially referenced data on the prevalence of HABs and toxin levels in GA ponds. This information, which is not currently available,  will inform nutrient management plans and BMPs that will ultimately improve nutrient management and water resources in Georgia.  We hope that this effort will serve as a model for other states experiencing similar increases in frequency and severity of HABs in agricultural settings.

Authors

Rebecca S. Haynie, Post Doctoral Associate, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 hayniers@uga.edu

Susan Wilde, Assistant Professor, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia 30602

David Kissel, Director and Professor, Agriculture and Environmental Services Laboratory, University of Georgia, 2400 College Station Road, Athens, Georgia 30602-9105

Leticia Sonon, Program Coordinator, Soil, Plant, and Water Analysis Laboratory, University of Georgia, 2400 College Station Road, Athens, Georgia 30602-9105

Uttam Saha, Program Coordinator, Feed and Environmental Water Analysis Laboratory, University of Georgia, 2400 College Station Road, Athens, Georgia 30602-9105

Additional Information

Haynie, R. S., J. R. Morgan, B. Bartelme, B. Willis, J. H. Rodgers Jr., A.L. Jones and S. B. Wilde.  Harmful algal blooms and toxin production in Georgia ponds. (in review). Proceedings of the Georgia Water Resources Conference. Athens, Georgia. April 2013.

UGA Agriculture and Environmental Services Laboratory: http://aesl.ces.uga.edu/

Burtle, G.J. July 2012. Managing Algal Blooms and the Potential for Algal Toxins in Pond Water. University of Georgia Cooperative Extension Temporary Publication 101.

Haynie, R.S., J.R. Morgan, B. Bartelme, S. B. Wilde. Cyanotoxins: Exposure Effects and Mangagement Options. Proceedings of the UGA Extension Beef Cattle Shortcourse. Ed. L. Stewart. Athens, Georgia. January 2013.

News article: https://www.wsbtv.com/news/local/experts-say-toxic-algae-may-pose-threat-kids-pets/242741856/

Acknowledgements

Drs. Lawton Stewart, Gary Burtle (Animal and Dairy Science, College of Agriculture and Environmental Sciences, UGA)  coordinated sample delivery from pond owners to our laboratory. Brad Bartelme, James Herrin and Jamie Morgan (Warnell School of Forestry and Natural Resources, UGA) contributed significant technical assistance with algal screening and sample processing.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

Why Should I Consider Composting Animal Mortalities?

Composting livestock and poultry carcasses is becoming a more common way to manage mortalities. There are several reasons for this.

Composting is relatively inexpensive when low cost carbon materials are utilized. The high temperatures generated during composting create a very biosecure process which eliminates pathogens and reduces disease transmission when properly managed.  Composting is also an environmentally sound method for carcass disposal as it reduces odors as well as carcass leachate by surrounding the carcass with a carbon filter. The composting process creates a beneficial by-product rich in nutrients which can be land-applied as a fertilizer. Composting promotes a positive public perception by adequately disposing of animal carcasses in a sustainable manner without negatively affecting the environment.

Check out the other video FAQs on carcass management

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University

What Temperature Is Required To Reduce Pathogens In an Animal Mortality Compost Piles?

Research studies have been done to correlate the temperature of a compost pile containing livestock or poultry carcasses and the amount of pathogen kill achieved at those temperatures. How do you take the temperature of a compost pile? And how does that temperature correlate to pathogen reduction?

Maintaining a temperature of 131 deg F for at least 4 hours assures us that we have reached an appropriate temperature for pathogen reduction. However, to destroy most pathogen and viruses, compost pile should sustain temperature 131 °F or greater for at least 3 consecutive days. The heat is the result of microbial metabolic activity within the compost pile as they are consuming the carcass.

Check out the other video FAQs on carcass management

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University

When Composting Animal Carcasses, Do the Bones Break Down? If Not, What Can Be Done With Them?

Most bones break down when composting animal carcasses, but a few large bones will usually remain.

With proper composting, the bones will break down over time. This may take several months for larger livestock bones and as little as 60 days for smaller carcasses such as poultry. If large bones remain in the compost pile, they can be added to additional compost piles until completely degraded.

Check out the other video FAQs on carcass management

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University

Can I Use Rendering As an Option For Managing Animal Mortalities?

There are many options available for disposing of livestock and poultry carcasses. Rendering is an option in areas where the service is offered, but has some limitations on the type of animals they will pick up.

Check out the other video FAQs on carcass management.

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University

 

What Should I Do With Compost That Includes Animal Mortalities?

Compost containing animal carcasses should probably be utilized on crops that are not meant for human consumption for a couple of different reasons.

Disposal of the end product with regard to roadkill compost…we use it on the roadsides and plant vegetation on the roadsides.

With [farm] mortality compost, we want to be careful about where we are putting cows and chickens because we are using it back on the farm. So we may want to remove the large bones [and reuse them as part of the base for the next mortality compost pile]. We do not want to puncture any tires. But the bones do get pitted and will start breaking apart after a couple of cycles of the composting process. We do not want to use this on food crops. We may prefer to use this on field crops where the soil is tilled. We can apply the compost and then till it in. Definitely use it on crops that are harvested above the ground…corn and things like that. Do not use [mortality compost] on root vegetable or on things where we risk contamination if there is a problem.

Mortality compost can also be used in forested areas.

Author: Jean Bonhotal, Cornell University

Why Is It Important To Manage Animal Mortalities Properly?

Improperly disposed livestock or poultry carcasses represent a threat to water and air quality.

Proper management of on-farm animal mortalities is vital to every farming operation. Improper disposal of dead animal carcasses can negatively impact surface water and groundwater from carcass leachate. If the animal died of an infectious disease, pathogenic bacteria and viruses may be present within the carcass. These pathogens can be spread by insects, rodents, preda­tors, and subsurface or above ground water movement, as well as through direct contact with other livestock or poultry leading to increased disease transmission risks. Furthermore, many states have rules regulating the proper disposal of livestock and poultry mortalities. Therefore, the purpose of proper mortality disposal is to prevent the spread of infectious, contagious and communicable diseases and to protect air, water and soil quality. Note that regulated AFOs must abide by their animal mortality disposal plan outlined in their nutrient management plan.

Check out the other video FAQs on carcass management

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University

What Are Common Animal Mortality Disposal Options

Managing dead animals is not pleasant, but is a necessary task for most livestock and poultry farms. This video discusses several options for disposing of carcasses in an environmentally responsible manner.

In most states, commonly approved disposal options include: burial, landfills, incineration, rendering and composting.

Burial

Perhaps the most common method of disposal is burial. Most states have regulatory burial guidelines outlining site location, distance from waterways, depth to groundwater, etc. When proper guidelines are followed, burial is a safe option. However, poor site selection, such as sandy soils or areas with high water tables, may pose a threat to groundwater. Furthermore, burial does not convert the carcass into a valuable by-product. Variable equipment and labor costs will influence the economic viability of this disposal option.

Landfills

Disposing of carcasses at a licensed landfill that accepts animal mortalities is another form of burial. Landfills may require notification before delivery and/or documentation from a licensed veterinarian stating the cause of death. Landfill tipping fees should be assessed and may range from $20 to $30/ton. Other considerations are transportation costs and breeches of biosecurity by moving carcasses off- farm. Similar to burial, a valuable by-product is not produced.

Incineration

Incineration is a safe and effective means of carcass disposal, especially from the standpoint of biosecurity. The carcass is completely consumed by fire and heat within a self-contained incinerator utilizing air quality and emissions controls. Some states may require air quality permits. Incineration is mainly designed for smaller carcasses and fuel costs should be considered. Due to odor and emission concerns, open air incineration (burning) is not recommended and banned in some states. Furthermore, obtaining complete consumption of the carcass in a timely manner is often difficult to achieve. Burning should only be used in emergencies for controlling infectious or contagious diseases with permission from a regulatory body.

Rendering

Another recommended carcass disposal method is rendering. This is a heat driven process that cooks the product while killing pathogens and converting it into a value-added product such as an animal feedstuff. These feedstuffs, such as meat and bone meal, are generally used as pet food ingredients. Although rendering is a very effective method, currently, there are few render­ing services available. The transportation expense of collecting small volumes creates a financial obstacle for most rendering companies. Some rendering facilities require the producer to transport carcasses to the plant and pay a fee. Biosecurity and disease transmission risks should be considered when allowing vehicles on the farm and when transporting carcasses off-farm.

Composting

Composting dead animal mortalities is an inexpen­sive, biosecure and environmentally sound approach to addressing the issue of carcass disposal. By definition, composting is a controlled biological decomposition pro­cess that converts organic matter into a stable, humus-like product. The carcass (nitrogen source) is buried in a bulking agent (carbon source), such as wood shavings, allowing for the proper carbon to nitrogen ratio (C:N) required by microorganisms to successfully decompose the carcass while absorbing excess moisture and filtering odor. The high temperatures achieved through proper composting will destroy most pathogens. Microorganisms will degrade the carcass leaving only a few small bone fragments, which are brittle and break easily. This valuable by-product can then be land-applied as a fertilizer source, adding nutrients and organic matter to the soil or recycled for new compost piles. As with burial, site selection is important. The site should be located in an area that does not pose a risk to surface or groundwater contamination.

Alternative methods:

Alternative methods are not specifically defined. They may include homogenization, digestion or chemical processes and technologies to recover products from mortalities.

 

Check out the other video FAQs on carcass management

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University

How Can I Manage Multiple Animal Mortalities?

Sometimes, a disease outbreak or natural disaster results in many livestock or poultry carcasses that must be managed. Disposal of these requires additional planning to ensure this is done in an environmentally responsible manner.

During catastrophic events when multiple livestock losses occur, a producer’s routine mortality disposal plan may be inadequate. In these instances, multiple disposal options may need to be considered. Burial, rendering, landfills, composting and incineration or a combination thereof are recommended options. All catastrophic events should be reported to the appropriate state agency. If a catastrophic mortality event is the result of disease outbreak, bio-security considerations may dictate the method of transportation and disposal.

Check out the other video FAQs on carcass management

Author: Joshua Payne, Oklahoma State University

Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University