The Benefits of In-House Litter Composting

poultry house litter composting

Management Guidelines for In-House Composting of Litter

In-house composting. Windrowing. Pasteurization. There are several different names for this type of poultry litter treatment, but, whatever you call it, the benefits are the same. The following article was written by Bud Malone, a poultry specialist and consultant based in Princess Anne, MD. It was originally developed for the 2010 Virginia Poultry Health and Management Seminar in Harrisonburg, VA, on April 13, 2010. It is republished here with permission from Bud Malone.

by Bud Malone
Malone Poultry Consulting
Princess Anne, MD

During the past few years there has been rapid adoption of composting the litter between flocks with a primary goal of reducing the pathogen load in poultry litter. The term for this procedure goes by different names; composting, windrowing and pasteurization. Implemented properly, this biological heat treatment reduces many heat-sensitive bacteria, viruses, parasites such as coccidia and darkling beetles. This litter treatment program has been a successful intervention strategy in reducing or eliminating many common poultry diseases such as dermatitis, necrotic enteritis, and runting and stunting syndrome. It is also been used to treat litter following a viral challenge such as laryngotracheitis. With some disease challenges the severity of infection decreases with each consecutive flock that is windrowed. Although some have implemented in-house composting as a means of reducing bedding replacement costs or as a waste management reduction/treatment strategy, it is often the improvement in production efficiency and bird health that drives adoption of this practice. Often the greatest benefit of in-house composting is from poultry farms having the poorest production cost and health.

The merits of this litter management technique will not be realized if the program is not implemented properly! Windrows can be formed with grader blades on tractors, skid-steer loaders or specially-designed windrowing equipment. Each windrowing method has advantages and disadvantages. Many have opted using the windrowing equipment since it pulverizes the litter, cake and hardpan; aerates, re-conditions the litter and forms desirable size windrows in the two-foot height range. Windrowers also turn piles more effectively than blades or skid-steer loaders. When using windrowing equipment on farms having a significant disease challenge it is important to incorporate all litter from along the sidewalls and corners into the piles for heat treatment. Depending on house width and litter depth, two or three windrows should be formed within two days following bird movement.

Often the greatest benefit of in-house composting is from poultry farms having the poorest production cost and health.

The goal is to achieve 130o F or greater temperatures within the first two to three days and to maintain these windrow temperatures for a cumulative period of time of three to five days. Turning the piles is important in assuring pathogens throughout the litter mass are exposed to the elevated temperatures. Litter moisture of 25% or more is often needed to achieve these temperatures. When the litter becomes dry and powdery following years of reuse and fails to heat properly, it may be advantageous to supplement it with wet bedding materials for added carbon, porosity and moisture. If time permits, allowing piles to heat for a total of 7 to 10 days is considered ideal. Equally important in this process is proper and timely re-spreading the piles and getting the litter base leveled back uniformly. A minimum of 4 days should be allowed between leveling the piles and chick placement. Table 1 depicts a typical schedule of events for a 14-day layout between flocks.

Proper implementation and in particular, managing ammonia is often key to the success of this program. Factors to minimize elevated ammonia levels with in-house composting include the following. Ideally, in-house composting should start the first flock following a total cleanout. Starting the program the first time on built-up litter releases excessive ammonia! When starting on built-up litter it is important to begin during warm or moderate weather in order to more cost effectively ventilate the house for ammonia control. It will also require at least a 25% increase in the rate of litter amendment for ammonia control, especially during cold weather. Managing litter depth in a range of 3 to 6 inches not only aids in reducing ammonia, it also enhances the windrowing process. At minimum, a partial house cleanout should be done annually as a means of managing litter depth. All hardpan should be removed during these partial cleanouts. Another key factor is to maintain constant ventilation after forming the windrows and following pile leveling. This is a necessary step to remove the ammonia and moisture that is released from the litter during the heating process. Turning windrows also facilitates the release of ammonia and moisture. Piles should be turned at least once. If time permits and resources are available, some of the more successful growers turn piles two or three times. There is a delicate balancing act between having enough moisture to get desirable windrow temperatures and avoiding excessive ammonia. If caking is excessive, it may be advantageous to remove the cake prior to windrowing particularly during cold weather. Tilling or removal of cake fragments after re-spreading may also aid in reducing ammonia and moisture. To avoid excessive ammonia challenge it may be best to skip composting for a flock if the layout is less than 10 days or in extremely cold weather with wet litter. Repeated composting over consecutive flocks conditions the litter and reduces the initial burst of ammonia of release often seen when starting this program. There may be another challenge with ammonia when re-starting the composting process after skipping multiple flocks.

Finally, in-house composting involves more cost and labor, and poses scheduling challenges during layout. For those farms having to deal with many types of diseases, when implemented properly and done repeatedly, in the majority of cases in-house composting improves performance and health. The benefits for these heath-challenged farms far exceed the added costs and labor. There are a number of factors to consider in determining if in-house composting is a program that should be adopted by average or above average growers and the frequency in which it should be done during the year. In Virginia, NRCS has recently approved in-house composting of litter between flocks for cost-share assistance under the waste treatment standard #629.

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Guidelines for Composting Poultry Litter

guidelines for composting poultry litter

Management Guidelines for Windrowing Litter Between Flocks

When it comes to composting poultry litter, it’s extremely important to follow a set of guidelines to help ensure positive and consistent results. Below is a set of windrowing litter guidelines that carefully explains all aspects of the process. Many thanks go to Bud Malone, an in-house composting expert and retired poultry specialist from the University of Delaware, who developed these guidelines and granted us permission to republish them here.

by Bud Malone
Malone Poultry Consulting
Princess Anne, MD

The following guidelines represent the current (2009) information for in-house windrowing of litter between flocks. This information is based upon research and observations during the past few years on Delmarva and other regions of the country. The procedures may be modified in the future as more experience is gained with this litter management technique.

Furthermore, the guidelines are based mostly on Delmarva broiler production practices, housing, litter management, climate and formation of piles using windrowing equipment. Modifications to these procedures may be needed for other regions of the US and with other species of poultry.

The ideal time to start in-house windrowing of litter is the first flock following a total cleanout. If starting with built-up litter, it might be best to implement windrowing during warm or moderate weather to minimize the challenge with controlling ammonia during the initial windrowed flock.

Windrowing should be implemented within 2 days following bird movement. If the litter is dry (~20%) it may be beneficial to close the houses prior to windrowing to minimize moisture loss.

One must manage litter depth in the range of 3 to 6 inches. If depth excesses 8 inches, a portion of the litter should be removed at least on an annual bases. This may be done in spring or fall and when there is adequate storage for the litter, land available for spreading according to nutrient management plans or other suitable alternative uses for the litter.

If caking excesses 3 feet wide and/or 3 inches thick under the nipple lines, it may be necessary to re-crust the house after the windrowing process. During cold weather it may be beneficial to remove this excessive cake before building the windrows.

When starting with built-up litter that has an excessive hard pan, windrow the loose litter and either remove the hard pan from the house or break it up sufficiently for incorporation into the windrow. In cold weather, it would be best to remove this hard pan from the house. In warmer weather and with dry litter, the hard pan may be incorporated into the windrow as an added source of moisture. Since it has been suggested that one of the benefits of windrowing is exposing the dirt floor to the atmosphere on a regular bases, as much as practical, removing all litter and hard pan from the floor is generally recommended.

The optimum windrow size is ~18 to 24 inches high and conical shape. This size windrow heats rapidly, is ease to turn and allows maximum moisture and ammonia release. The number of windrows per house will depend on litter depth and house width. All litter, including that under the windrow base should be turned and go thru the heating process.

From a pathogen reduction standpoint the goal is to reach at least 130 F and maintain these temperatures for a minimum of 3 to 5 days. Approximately 3 days after constructing the windrows the piles should be turned. Turning exposes the cooler portion of the pile to the higher temperatures. It is important to monitor and record temperatures daily. An inexpensive digital thermometer with a 1 foot long probe inserted into the top of the pile is one option for monitoring windrow temperatures. Since temperatures vary at different depths and piles vary in height, for consistency purposes, it may be helpful to place the temperature probe at 50% of the pile depth.

For farms with a significant disease challenge, it would be best to remove all litter from the sidewalls and corners and incorporate this litter into the windrow. Any undistributed litter under the windrow base should also be incorporated during the turning process. A wash down prior to windrowing incorporates the pathogen-laden dust into the pile and adds moisture, aiding in increased compost temperatures and pathogen kill. Additionally, for farms with a significant disease challenge, it may take 2 consecutive windrowing events (flocks) to break some diseases (ie. dermatitis) and the disease may re-appear if the litter is not windrowed for 2 consecutive flocks.

A minimum of a 10 day layout is often needed to implement the windrowing procedure. Windrowing should be avoided if there is inadequate layout time as sometimes occurs during summer flocks or in extremely cold weather with wet litter that does not allow adequate conditions for moisture and ammonia removal.

It is best to turn windrows at least once, and several times if possible. Turning helps release moisture and ammonia, may increase pile temperatures, reduce cake and increase the percentage of pathogen kill in the litter mass. If time permits, turning windrows on a 2 to 3 day cycle may be a consideration.

If caking or moisture is excessive, re-crusting the house after leveling the litter may be required particularly in cool weather.

If piles are formed with a skid-steer as sometimes required for pole houses, turning may not be an option. These larger piles tend to take longer to reach desired temperatures in the core of the pile. Although the amount of cake if often reduced by as much as 50% in the windrowing process, the house will need to be re-crusted after leveling the litter.

Within an hour darkling beetles will start migrating to the surface of a freshly windrowed pile. An ideal time to get maximum beetle kill may be to apply a quick-kill insecticide to the windrows within the first 12 hours after pile formation. Also, band application along the sidewalls should be considered if this litter is not incorporated into the windrow. If scheduling insecticide application immediately after pile formation is not an option, the regular pre-placement treatment can be used. There may be an opportunity to decrease the frequency of insecticide application since windrowing aids in reducing darkling beetle populations.

Closing houses following windrowing to retain house temperatures will have little impact on windrow temperatures! More important, in a closed house there will be very high (and dangerous) levels of ammonia, carbon dioxide and moisture. For solidsidewalls houses during warm and moderate weather, several tunnel fans should be run continuous with air being pulled thru the inlets. In colder climates it may be necessary to reduce air flow by running minimum ventilation fans set on timer or thermostat.

Ventilation to remove ammonia and moisture should be provided from the day of windrowing until chick placement. When the windrows are being turned, maximum ventilation should be provided to help remove the moisture and ammonia as it is being released from the steaming piles.

All operators should wear a respirator with ammonia filters when constructing, turning and spreading windrows.

The windrows can be spread out and leveled with a blade, skid-steer and/or windrowing equipment. Box blades and windrowing equipment with an adjustable skid to get consistent depth works well. It is critical adequate time be devoted to get the litter level. Leveling the piles at least 4 days prior to chick placement is generally recommended. When the layout schedule permits, leaving the windrows piled for a minimum of 7 days, and 10 day if possible, may promote additional ammonia and moisture volatilization losses.

To minimize the potential for high ammonia levels in the subsequent flock following windrowing, it is essential to follow the steps previously mentioned. Higher levels of litter amendment (~25% more) may be required particularly in cool weather to suppress ammonia. Litter amendments should not be applied within 2 days after leveling the piles. Higher ventilation rates may also be needed during brooding to control ammonia when first initiating a windrowing program. Ammonia control tends to be more manageable after the first or second flocks once starting the windrowing program on built-up litter. Failure to control ammonia during the brooding period can result in poor performance and partially defeat the benefits of the windrowing program!

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Now that you know all of the best practices for composting poultry litter, it’s time to take a closer look at the Creek View Windrow Composter. To request more information, complete the form or call 864-508-2447. You can also Download the Guidelines here (PDF).