Manure Management from Facility to Field

9/15/21

“Farmers are outstanding in their field.” – Unknown

Facilities:

Barn design

Considering barn design in relation to livestock and poultry manure output can be critical. Designing low-cost facilities while balancing their efficiency can depend on species and production considerations. For example, dairy cows create considerable amounts of wet manure and urine, making bedded pack barn design and maintenance different than it would be for sheep and goats. Pigs are naturally curious, relatively clean animals and there are innovations in manure management in sow facilities, allowing for more space, more comfortable sand flooring and separate “bathroom” areas to which adult pigs will retire to defecate (Van der lin 2020). Roosting birds naturally eliminate while getting on and off the roost. Designs that allow for the roost to be moved during cleaning keep working conditions efficient. 

Handling facilities and equipment necessary

Knowing the volume and consistency of manure that needs to be dealt with is key in determining what kind of equipment and handling facilities are best suited for the job. When handling large volumes of manure, either because of stocking density or large animals, it is advisable to consider larger equipment to move the manure. Skid steers are well suited for many different tasks, and can fit into smaller spaces, while still being strong enough to handle heavy loads. Conversely, dryer manures, smaller animals and lower stocking densities can be easily handled with hand tools. 

Manure storage is another important consideration. Having systems like a dedicated concrete pad, gravel lot or covered composting shed can keep manure management efficient. Location of these kinds or systems is also important, since managers need easy access in all weather conditions. Beyond the basic structure of the storage facilities, drainage and driveways need to be constructed mindfully to mitigate wet areas and allow for enough space to maneuver any equipment. In larger production and processing facilities, assistance in correctly calculating the necessary size of manure holding facilities can be done by Natural Resources Conservation Service (NRCS) engineers or extension personnel. Factors to take into consideration are not only manure volume, but also the amount of bedding used, as well as additions from wash water and rainwater (Fulhage and Hoehne 2001, 23-24). 

Advantages of composting vs. raw manure

When space and stocking densities allow, composting manure can be an effective way to mitigate fly populations and potential harmful pathogens. Properly composted manure may be applied directly to fruit and vegetable crops with little danger to humans. To qualify as properly composted manure in an organic systems plan, piles must reach a minimum of 131 F for at least three days. Best practices in assuring the entire pile reaches these temperatures is to build manure piles in rows that can be stirred and to incorporate adequate organic material and moisture. Different bedding materials and manure consistencies change the nature of each composting pile. The actions of heating and turning these piles help to disturb fly larvae and kill pathogens. However, these practices take time and real estate. It can be a better management decision to deal with raw manures. For organic certification and food safety, it is important to remember the 90/120 day rule which states that raw manure must be incorporated into the soil 90 days before harvest of crops which are not in direct contact with the soil, and 120 days for crops that do come in contact with the soil (MOFGA Certification Services 2021, 12). 

On Pasture:

Differences in manure between species

There are obvious differences in manure composition between species. Basic behaviour also plays a part in manure distribution throughout pastures. For example, sheep and goat manure is pelletized, and if animals are moved to new paddocks often enough, extra manure management should not be necessary as these pellets break apart and fall through to the soil readily enough. On the other hand, llamas, alpacas and stallions tend to be territorial and defecate in large piles. To better utilize these nutrients and manage pests, these piles can be gathered and integrated into manure holding facilities or be more evenly distributed into paddocks. Typical horse manure structure needs more intensive management, as it exits the body in a form that creates dryer, more immovable piles. Frequently dragging paddocks can be an adequate strategy for keeping pastures useful and palatable. Manure from cattle forms pats that are wet and shallow, making them prime sources for feeding adult dung beetles and harboring their young which helps to disturb biting fly larvae. As the top layers dry quickly, these pats become less hospitable for biting flies to mature in. Chicken behaviour involves foraging but also roosting. While foraging can spread this nutrient-dense manure widely, roosting creates noxious piles in coops. Considerations in coop design should be taken. Often a good solution is to build a portable coop with a slatted floor, which will allow feces to fall through, and the coop can be moved when the ground beneath has become soiled. 

Parasite life cycle

“A parasite is a smaller organism that lives on or in and at the expense of a larger organism called the host. A louse is a parasite and so is a virus” (Bowman 1999). 

As stated by the American Institute for Goat Research (2020):

“Worms mate in the host and females lay eggs that pass out in the feces. The eggs hatch and develop to infective larvae while remaining in the feces. The infective larvae then move out of the feces onto the surrounding forage where they can be consumed during grazing thus completing the cycle. The time from ingestion of infective larvae to egg laying adults, called the prepatent period, is about three weeks and the time for development from egg to infective larvae can be as short as 7-10 days … ”

Taking into consideration the development time of internal parasites, we, as managers, need to make sure our livestock are moved to a clean foraging location, no less than weekly, to avoid high infection rates. It also helps to break the parasite cycle if we have enough paddocks to avoid returning to any for at least 30 days, thus avoiding issues caused by potentially heavily infested animals while managers work to remedy the infestation. If options are limited to a high-use area (due to stage of life or adverse weather conditions), making sure feed is either off the ground in a manger, and dropped feed is routinely cleared away, or livestock have access to a feed alley can prove critical in managing internal parasite loads.

With regards to manure management, it is important to consider the presence of maggots. Flies of all kinds breed and lay their eggs in decaying plant matter and feces, which can pose an insurmountable challenge in identifying friend from foe. Therefore, livestock managers must study parasitic life cycles. The average time it takes for eggs laid by the adult fly to hatch into maggots, and subsequently pupate, is around three to four days (Australian Museum 2019). When flies are creating issues on a farm, start at the source and either clear manure away into a management area or spread piles thinly by dragging to allow them to dry, therefore killing larvae populations. 

Dung Beetles

Dung beetles are fascinating little creatures. “By eating both parasites and human pathogens, dung beetles can greatly improve human and livestock health. It should be noted that dung beetles feed on fresh feces, so pathogens found in improperly composted manure may be less likely to be consumed by dung beetles” (Jones and Snider 2017). Organic production prohibits the use of raw manure as a fertilizer unless it is applied in accordance with the 90/120 day rule, therefore any manures added to vegetables must be composted in accordance with certification guidelines (MOFGA Certification Services 2021, 12). Therefore, pasturing livestock to manage their manure can be one of the best practices to enhance local populations of dung beetles. 

There are three types of dung beetles in this scarab beetle family. Rollers are what most people think of when considering dung beetles, as they are seen often in nature documentaries carting off elephant feces. These pooper scoopers form balls of manure and roll them away to a nest, where the males are able to guard this source of feed for their young. They are often equipped with a “horn” and powerful front legs to aid in these tasks. Dwellers are found living and breeding directly in manure piles. Tunnelers don’t live directly inside piles of manure, but transfer these nutrients to their underground tunnels. All adult dung beetles are equipped with a keen sense of smell and the ability to fly, allowing them to find choice piles of manure to feed their young. It is not the adulte beetles that feed on manure, but rather the larvae. Adults subsist on primarily a liquid diet. This would lead us to believe that in dry years it may benefit the dung beetle population to wait the maximum time of four days before exposing manure patties to sunshine, allowing adults proper nutrition. 

“High stock density grazing favors dung beetles by supplying many manure pats in a small area for easy colonization” (Duiker 2017). It has also been found, in a study conducted in 2010 by entomologists from the University of Nebraska, that a wider variety of dung beetle species can be found on the feces of omnivores (Whipple and Hoback 2012). This supports the theory that livestock diversification and rotation has the potential to increase soil health by introducing a wider variety of dung beetle activity. However, care should be taken when the use of parasiticides is deemed necessary, as they also kill off large numbers of dung beetle larvae. Organic certification allows for the temporary confinement of treated livestock, which in relation to dung beetles need only be for a period of 24 to 48 hours (MOFGA Certification Services 2021, 23). 

Paddock Rotation in Relation to Manure

To summarize, some best practices of pasture management are as follows:

  • Adjust paddock size and/or stocking density to move animals on and off grazing ground as quickly as possible. Having good perimeter fences with strategically placed posts can allow for flexibility in paddock sizes as weather conditions change.
  • Time management often plays a leading role. While having the time to shepherd livestock across our grasslands might be ideal, the realities of life might mean that setting a schedule to graze and move livestock at 12-hour intervals is most feasible. Conversely, if one has low stocking density and little time, grazing livestock should not be left on a parcel for longer than three days to avoid back grazing, or grazing too short, which causes animals to eat too close to the soil surface and increases the likelihood of parasite infestation. 
  • Never return to a previously grazed area before 14 days in an effort to break the parasite cycle. Thirty day, or longer, rest periods are ideal, mainly for the health of grasses.

Nutrient management (clipping and dragging)

It is prudent when dealing with manure in our pastures to be able to employ various management techniques. Most cool season, perennial grasses that livestock find palatable grow so rapidly in the spring that it can become necessary to clip pastures after animals have grazed through. Allowing these grasses to form seed heads and naturally reseed an area can help to restore our pastures, as livestock graze and trample their way through a paddock. 

Clipping can also help to expose manure to light and air, and make redistribution of piles easier, all of which serve to mitigate fly and parasite pressure. There is also something to be said for allowing the organic matter of passed-over feed to decompose and return to the neverending nutrient cycle. It is worth noting, however, that pastures should be clipped, ideally, as soon as animals have been moved to a new area, and no later than three days following that move, to avoid setting back the regeneration process of the plants. Should extenuating circumstances occur and this window be missed, setting cutting heights high enough to avoid taking new growth is a good option. 

Dragging and redistributing manure, however, can possibly be postponed for up to seven days, allowing dung beetles time to work the piles, but not enough leeway to give biting fly larvae the opportunity to hatch. Another positive outcome to dragging pastures to redistribute manure piles is that animals are less likely to avoid certain areas in which they have already defecated, since manure is now spread evenly enough for it to fall below the height of 4 to 6 inches which we do not wish to graze below. Livestock will naturally graze within 4 inches of old, dried manure, so if it is spread out and close to the soil managers are better able to maximize available grassland. When planning paddock layout, keep in mind that nitrates and other pathogens have the potential to leach into groundwater supplies. Keep stockyards 100 to 150 feet away from private drinking wells (Uhlman, et al. n.d.) 

Resources:

  • MOFGA Farmer Programs
  • University of Maine Cooperative Extension
  • University of Missouri Extension
  • Natural Resources Conservation Services (NRCS)
  • Washington State University
  • University of Nebraska
  • Texas A&M

References:

American Institute for Goat Research. 2020. “Internal Parasites.” Langston University.

Australian Museum. 2019. “Decomposition: fly life cycle and development times.” January 25, 2019. australian.museum/learn/science/decomposition-fly-life-cycles

Bowman, Dwight D. 1999. Georgis’ Parasitology for Veterinarians, seventh edition. St. Louis: Elsevler. 

Duiker, Sjoerd Willem. 2017. “The Lowly Dung Beetle.” PennState Extension. September 11, 2017. extension.psu.edu/the-lowly-dung-beetle.

Fulhage, Charles and John Hoehne. 2001. Lesson 21: Sizing Manure Storage, Typical Nutrient Characteristics. Ames, Iowa: MidWest Plan Service. lpelc.org/wp-content/uploads/2019/03/LES_21.pdf

Jones, Matthew S. and William E. Snider. 2017. “Dung Beetles: How to Identify and Benefit from Nature’s Pooper Scoopers.” eOrganic. December 29, 2017. eorganic.org/node/23262

MOFGA Certification Services, LLC. “Practice Manual.” 2021 mofgacertification.org/wp-content/uploads/All_PracticeManual2021-FINAL_web.pdf

Uhlman, Kristine A., Diane E. Boellstorff, Saqib Mukhtar and Mark L. McFarland. n.d. “Managing Livestock Holding Pens to Protect Groundwater.” Texas A&M Agrilife Extension. Service. agrilifeextension.tamu.edu/library/ranching/twon-managing-livestock-holding-pens-to-protect-groundwater

Van der Linde, Anne-Marie. 2020. “Welfare and environment key in innovative barn design.” Pig Progress, December 4, 2020. pigprogress.net/World-of-Pigs1/Articles/2020/12/Welfare-and-environment-key-in-innovative-barn-672113E
Whipple, Sean D. and W. Wyatt Hoback. 2012. “A Comparison of Dung Beetle(Coleoptera: Scarabaeidae) Attraction to Native and Exotic Mammal Dung.” University of Nebraska Department of Entomology. digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1636&context=entomologyfacpub.

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