NE1441: Environmental Impacts of Equine Operations

(Multistate Research Project)

Status: Active

NE1441: Environmental Impacts of Equine Operations

Duration: 10/01/2014 to 09/30/2019

Administrative Advisor(s):

NIFA Reps:

Statement of Issues and Justification

One of the serious challenges on horse farms is the disposal and management of manure. Many smaller horse farms (Westendorf, et al., 2010a) indicate that disposing of horse manure is one of the chief challenges in equine management. A combination of increased horse numbers and insufficient acreage may limit the ability for on-farm usage; nearly 58% of surveyed farmers indicated that some manure was disposed off-farm while only 54% spread any manure on the farm (Westendorf et al., 2010a). Of further concern, is the low adoption rate of various manure Best Management Practices (BMP's); Fiorellino et al. (2013a,b) indicate a lower adoption of some environmentally friendly BMP's, but that participating farms still posed a low potential for non-point source (NPS) pollution. Several studies have shown poor adoption and use of soil test information in making manure spreading decisions (Fiorellino et al., 2013ab; Westendorf et al., 2010a; Marriott et al., 2012). Marriott et al. (2012) and Westendorf et al. (2010b) found that most equine property owners were either unaware of or did not use cooperative extension or other conservation services; Singer et al. (2002) suggests that extension programs should target smaller property owners. Best management practices related to pasture management are only sporadically applied. Most farmers are either not aware of soil testing on pasture or dont utilize results in managing fertility. Continuous grazing, overstocking, and lack of weed control also influence pasture management (Fiorellino et al., 2013ab; Westendorf et al., 2010a; Marriott et al., 2012). Many horse producers are not interested in managing manure or pastures on-farm and when given the choice ask how manure can be disposed off-farm. While manure is often stored away from water or wetlands, manure storage structures are often non-existent and manure storage areas often contaminated by encroaching stormwater. A study (Westendorf et al. 2013) of 21 New Jersey horse farms (USDA-NRCS/CIG, 2009-2012) found that these farms averaged 276 pounds per acre of phosphorus. Only five of the farms were not in the excessive range. The Phosphorus Index is a manure management risk assessment based on soil type, slope, distance to water, potential for soil loss, soil test phosphorus, crop and cropping system, and manure spreading management (; it is a tool used to assess the potential for phosphorus to move from agricultural fields to surface water. Elevated soil P levels and poor adoption of pasture management BMPs can identify areas of increased phosphorus runoff risk.

The work proposed here will develop new manure storage and management methodologies for equine producers. Since many do not have appropriate storage facilities or sufficient land for spreading, our first objective will be to develop appropriate low-cost storages for producers, and increase opportunities for off-farm disposal. Research will focus on adoption of composting technologies (Komar et al., 2012) for equine producers and the use of different bedding types and production for off-farm uses. Another emphasis will be on the energy potential of horse manure. Horse manure, irrespective of bedding type, averages about 7,200 BTUs/pound. While horse manure may not be suitable for anaerobic digestion, we hope to develop a product (pellet, briquette, etc.) that can be combusted to produce heat and for greenhouses, farm shops, etc.

Pasture management and the adoption of BMPs is a second objective. Because many equine pastures are poorly managed, we will emphasize BMPs that are readily adopted. Use of appropriate pasture mixes for seeing and renovation techniques are essential. The use of feeders to decrease mud in and around feeding areas, appropriate footing materials for dry lots, rotational grazing systems instead of continuous grazing, and proper stocking densities are all important for developing a more environmentally sustainable equine management model.

A Best Management Practice (BMP) refers to management practices effective in preventing or reducing pollution from nonpoint sources. Most, if not all, horse farms are non-point source polluters. The BMPs referred to here are separate from manure storage and disposal or pasture management, which we view as separate categories. These BMPs would be anything that mitigates non-point source pollution such as streamside buffers, roof gutters, heavy use pads around feed lots, and vegetative filters around manure storages. Much of this research would focus on feedlot management. Since horses spend significant amounts of time in dry lots for resting or exercise these areas can have mud and water runoff problems when it rains. We will conduct research in appropriate low-cost footings, feeding and watering stations, shelter, the use of these dry lots as hubs for rotational grazing, etc.

Feeding management and stable management are two other research areas or objectives. Elevated levels of phosphorus in the diet resulted in increased phosphorus excretion and possible increases in phosphorus runoff potential in manure (Westendorf and Williams, 2011); the greatest increase came in the level of water extractable phosphorus (Wolf et al., 2005). Williams et al., (2011) found an increase in nitrogen excretion and barn levels of ammonia when excess nitrogen was fed. Further research is planned with differing nitrogen and phosphorus levels in the diet. Some of this will focus on the use of different forages, BUN production, and nitrogen excretion. We will compare ammonia levels in stables on different managements. Some of this will be a field and/or a comparative study between states.

The research we propose is feasible considering our research team. Several states have strong equine environmental programs. In the course of the previous project (NE-1041) pasture management research was conducted by Rutgers University, the University of Minnesota, North Carolina State University, the University of Vermont, Pennsylvania State University, the University of Maryland, and the University of Massachusetts. Manure storage and disposal work have been done at Rutgers University and Pennsylvania State University. The development of Best Management Practices has been done at Rutgers University, the University of Minnesota, North Carolina State University, the University of Vermont, Pennsylvania State University, the University of Maryland, and the University of Massachusetts. Feeding and management work has been done at Rutgers University, the University of Minnesota and the University of Michigan. And stable management work has been completed at Rutgers University and Pennsylvania State University. This list is not comprehensive as other states have contributed as well.

These states are well-equipped to conduct research about the environmental impacts of equine operations. A multi-state approach allows us to leverage other state resources to conduct research with different management systems. In the end our research, recommendations, and extension outreach will be stronger and better able to meet the needs of a diversity of systems.

We hope for a variety of impacts, but the main two would be to improve rotational and pasture management systems and to develop more storage and disposal options for farmers. Improving rotational and pasture management will impact through increasing field ground cover, lowering stocking density, increasing soil organic matter content, decreasing soil erosion and reducing the effects that insufficient ground cover might have on non-point source pollution risk.

We hope to encourage the use of more appropriate storage methods for small farms. This will include the use of centralized composting areas. There are many of these present in the northeast. Composting as an option for small farms will be pursued. Different bedding sources and their influence on storage, composting and disposal, and effects on horse stall management will be considered. Success in this objective would be an increase in composting among small horse farmers and an increase in appropriate techniques among the many who think they compost. Finally, it is hoped that examining the use of horse manure as an energy source will result in the growth of several pilot projects.

Related, Current and Previous Work

Grazing Management: Continuous grazing systems for horses often lead to selective grazing where preference is given to some areas of a pasture while other areas are avoided. Preferred areas eventually become overgrazed, while the avoided areas become latrines (Archer, 1973; Fluerance et al., 2007). Overgrazing results in the decline of forage quality and quantity due to impaired ability for re-growth (Matches, 1992; Hubbard et al., 2004; Bilotta et al., 2007). The lack of forage quantity reduces forage canopy coverage. Forage canopy coverage of less than 70 to 80% can lead to significant erosion and subsequent soil nutrient loss (Butler et al., 2007). Furthermore the uneven distribution of grazing and manure deposition leads to inefficient land (Odberg, 1976) and plant nutrient uptake from manure (Peterson and Gerrish, 1995).

Negative environmental impacts associated with grazing can be avoided by implementation of grazing best management practices such as rotational grazing (Teague and Dowhower, 2003). Unfortunately, many horse-owners/manager fail to implement these practices correctly (Privatsky et al., 2013; Swinker et al., 2011). These findings may suggest that horse owners do not fully understand the practice of rotational grazing (i.e., the necessity of allowing time for plants to fully recover from grazing).

Restrictive grazing in conjunction with rotational grazing is another method that may also be useful in preventing overgrazing and its negative environmental impacts. Restrictive grazing is accomplished by limiting the amount of time a horse spends at pasture so that horse graze only long enough to consume a targeted dry matter intake. For example, Dowler et al. (2012) measured pasture DMI and pasture DE concentration, and then used these measures along with a horse s maintenance DE requirement to determine the amount of time required to consume maintenance DE requirements. This approach appeared to be successful in limiting dry matter intake to an amount providing only the daily DE required for maintenance. One caveat with this approach is that pasture DMI rate does not appear to be constant over a wide range, and is accelerated when pasture access is restricted resulting in greater consumption of forage than would be expected when grazing periods are restricted significantly (e.g., three to six h/d) (Dowler et al., 2012; Glunk et al., 2013). In order to address this problem an equation was developed using available values from the literature to predict DMI over a range of pasture access times (Siciliano, 2012). However, this equation remains to be validated in a variety of practical settings.

Selection of a mix of pasture plant species that vary in palatability may also be a strategy for preventing overgrazing and maintaining ground cover. Horse pastures are primarily comprised of legumes, warm-season and/or cool-season grasses. Horses determination of palatability is based upon combinations of not only the offered plants, but also the environment in which the plants are grown. Although much research has focused on horse grazing preference of cool-season grass (Allen et al., 2013), little data exists on horse preference when grazing legumes and warm-season grass. Although horse preference is important to maximize forage utilization, the goal of any pasture management program should be to maximize yield and forage persistence. To maximize pasture yield, species selection should be based on both persistence to horse grazing and yield potential.

Although research investigating horse preference and forage yield and persistence to individual species is important, horse pastures are rarely planted to a single species. Planting mixtures is common; however, mixtures are rarely evaluated under horse grazing. Recent research suggested that to maximize forage use, promote uniform grazing, and maximize forage yield and persistence, mixtures containing meadow fescue, Kentucky bluegrass, perennial ryegrass, and orchardgrass should be planted in horse pastures in the North Central U.S (Martinson and Sheaffer, 2013). Pasture mixtures of various forage mixtures need to be investigated throughout the U.S.

The successful implementation of any pasture/grazing management practice will depend upon the development of sound educational tools for horse owners. Efforts in this area are currently underway. The University of Maryland (Burk et al, 2013) has developed a rotational grazing demonstration that provides a great resource for horse owners in that region. Additionally the same group has developed a YouTube video clip on estimating pasture plant composition using the step-point method. Pennsylvania State University has also developed the Equine Pasture Evaluation Disc (Foulk et al., 2011a,b) which is has proven to be an effective means of predicting pasture plant composition and ground cover.

Manure Storage and Disposal: The use or implementation of appropriate manure storage and disposal practices can help to further reduce the risks that animal waste will contaminate water or air. Westendorf et al. (2010a) conducted a survey to assess BMP usage in NJ. The results indicate that although most equine farms did not pose a direct risk to water quality or to a neighbor, most do not currently use best management practices in managing, spreading, or storing manure.

Manure on horse farms is generally stored solid. A variety of storage facilities and bedding sources are used for horses (MWPS, 2005). Wood products are the bedding of choice for many equine producers. Ward et al. (2001) and Komar et al. (2012) studied the use of bedding and determined bedding effectiveness. The advantage of straw for availability and ease of disposal was hurt by the fact it tended to be less absorbent in a stall. Pratt et al. (1998) found ammonia in stalls to be a health concern. In some regions of the country (Westendorf and Krogmann, 2006) straw bedded horse manure is in demand on mushroom farms.

Manure storage can be very simple or quite complex. When properly managed, flies, odors, dust, and particulate matter can be controlled. Manure should be kept as dry as possible since wet manure provides a breeding ground for flies and mosquitoes. A roofed storage area may be advisable to keep manure as dry as possible when stored for long periods of time.

Stockpiling is when the solid manure and soiled bedding are piled in a convenient location. The cost involved with this system is relatively low. This method can be acceptable for a small farm with just one or two horses. However, the spot must be compacted and sealed so that rainfall landing on the pile cannot leach pollutants into the soil and groundwater.

Dry stacking is probably the most common and practical choice for the small livestock operation. The cost of this method is moderate. The walls of a dry stack facility should be a minimum of four feet high and the back walls must be stout since the manure will be exerting outward pressure as the pile grows higher.

Composting is a recommended management practice for horse manure and, when done properly, will result in the destruction of internal parasites and weed seeds. The composted product can then be spread on pastures. Composting is a managed process, resulting in accelerated decomposition of organic materials. Microorganisms, including bacteria, Actinomycetes, and fungi will break down organic materials at elevated temperatures. Compost from horse farms can be used as a soil amendment that provides organic matter, nutrients, and many other environmental benefits. Proper compost management and storage can help reduce sources of pollution to watershed areas such as nitrogen, phosphorous, and pathogens.

Waste accumulated from livestock operations represents a significant potential source of nutrients and bacteria to adjacent receiving waters. When waste is released from an agricultural facility it will accumulate in receiving waters leading to potential outbreaks of diseases that are present in fecal material or eutrophication from enhanced inputs of phosphorus and nitrogen. Animal manures can contain numerous pathogens that are potentially harmful to humans (Azevedo and Stout, 1974). Eutrophication is the most common impairment of surface waters in the United States (USEPA, 2000). In aquatic systems, high concentrations of waste nutrients can lead to excessive production which can result in several impairments such as toxic algal blooms, anoxia, fish kills, loss of biodiversity and other impairments (Carpenter et al., 1998).

Stormwater runoff from livestock areas has been found to contain high nutrient concentrations. The nutrients present in the daily waste of a single 1000 lb horse are 0.31 lbs of nitrogen and 0.072 lbs of phosphorus (Godwin and Moore, 1997). High livestock densities often result in soil and groundwater nutrient contamination because the amounts contained in the animal manures exceed the capacity of the local agricultural land base to utilize them for crop production (Power and Schepers, 1989), and because it is often not economical to transport manure far from the animal operations (Eghball and Power, 1994).

Elevated phosphorus concentrations in the soil result in a greater potential for phosphorus runoff to aquatic ecosystems (Fluck et al. 1992). The dominant phase for phosphorus in runoff is absorbed to soil particles (Daniel et al. 1993, Sharpley et al. 1994). These particles are then suspended in runoff during storm events and carried to lakes, streams and rivers. In most fresh water systems phosphorus is the limiting nutrient for growth and thus the primary cause of eutrophication.

Nitrogen is transported in runoff in both the dissolved and particulate phases. Thus nitrogen can travel in surface water, but also infiltrate and travel through groundwater. For most temperate estuaries and coastal ecosystems, nitrogen is the limiting nutrient for primary production (Howarth and Marino, 2006).

Feeding and management: Overfeeding can result in overspending on feed, over-conditioned horses, and harmful nutrient interactions, and may also have destructive influences on the environment. Animals acquire nitrogen from protein in the plants they eat. However, only 5-30 or 45% of consumed protein is utilized and made into animal protein, leaving a substantial amount of organic N to be excreted in urine or feces (Follet and Hatfield, 2001; Oenema and Tamminga, 2005). That amount will be significantly increased if animals are fed in excess of their recommended amounts. It has been reported that horse owners commonly overfeed protein over what is recommended by NRC (Swinker et al., 2009; Harper, 2010). Horses at maintenance were associated with greater overfeeding than working horses. This could lead to horse farm operations contributing to environmental excesses of nitrogen in soil, water and air.

While N is an important and necessary fertilizer in agricultural production, it can have negative consequences on air and water quality when it travels from the site of deposition. Nitrogen is excreted from animals as organic nitrogen and ammonia; organic nitrogen is slowly available to plants over a several year period, ammonia is available immediately but can also be volatilized or lost in the surface waters (Koelsch and Shapiro, 2006). Nitrogen from stall waste can build up in the soil and run off into waterways leading to eutrophication. Many methods to reduce environmental impact of livestock operations that have been previously tested and implemented on cattle and swine concentrated animal feeding operations (CAFOs) in the United States (Rotz, 2004), however, equine research and implementation is much slower to follow.

In a study done in horses fed at about 165% of the recommended protein amount authors showed that elevating protein levels in a horse s diet increases the ammonia and nitrogen levels excreted in manure, the ammonia in the atmosphere, and the urea nitrogen in the animal s blood (Williams et al., 2011). More specifically fecal nitrogen and ammonia were higher (approximately 35 and 50 % higher, respectively) in the high protein fed horses than in the control fed horses. When atmospheric ammonia was tested there was a significantly higher level of ammonia in the air in the stalls of horses fed the high protein diet (Williams et al., 2011). However, as far as the authors know there has never been a study evaluating the health of equine farm workers when they are subjected to confined horses with high protein diets.

Phosphorus is particularly a concern because of its effects on water quality and the environment when overfed (Sharpley et al., 1994). Water extractable phosphorus (WEP) has been evaluated previously to compare different materials on the basis of their potential to release dissolved P to runoff water (Wolf et al., 2005).

One of the chief components related to waste excretion is the concentration of nutrients in the diet and overfeeding. Work with dairy cattle has indicated that P levels can be reduced in the diet without influencing animal performance (Valk et al., 2001; Wu et al., 2001; Knowlton et al, 2002). Work with swine and poultry has shown that dietary modifications, the use of low phytate feedstuffs, or the use of phytase enzymes in swine or poultry diets can also reduce the level of nitrogen and phosphorus excretion (Angel et al., 2005). Phytase is an enzyme that can break down the indigestible phytic acid (high in phosphorus) in cereal grains and release phosphorus for use by swine or poultry. Microbial action in the ruminant breaks down phytic acid without the use of phytase (Clark et al., 1986).

Phosphate from manure can build up in the soil and may run off into waterways resulting in potential harm to the environment. When it enters waterways, phosphorus can have a significant impact on aquatic plant growth and lead to eutrophication (Sharpley et al, 1994). Nitrogen and phosphorus from agriculture have been shown to lead to this nutrient enrichment and eutrophication.

Less research has been completed with horses on the subject of the excretion of waste or excess nutrients. The latest Nutrient Requirements for Horses (2007) indicates diet composition will influence the amount and composition of waste. Schryver et al. (1971) found that ponies fed increasing levels of phosphorus had greater levels of phosphorus excretion; excretion was greater in feces but percent increase was greatest in urine.
One study (Westendorf and Williams, 2013) fed horses a low P diet meeting the NRC dietary requirement and a high P diet with about 2.5 times the recommended amount. The horses on the high P diets had a significantly elevated level of P in their feces. This study was designed to demonstrate the effect of added P in the form of an inorganic supplement on P excretion. The supplement used, NaH2PO4 is readily soluble in water and has been reported to have a good bioavailability for animals (NRC, 2007, Peterson, et al. 2011). The WEP was also significantly higher in the group fed a high P diet.

The fecal concentrations in the study by Westendorf and Williams (2013) are consistent with published values. When manure is spread it is delivered as pounds per ton. The supplement group had a manure concentration (as phosphate) two times the control. There was an increased concentration of WEP in the added P group. This indicates that the increase in P excretion due to high solubility results in a significant increase in WEP in the feces. This results in a greatly increased runoff potential for P.

Another study has looked at phosphorus and phytate-phosphorus on horses excretion level of total phosphorus and WEP (Weir et al., 2013). They found that horses that were fed an excess of 3 times the recommended amounts of phosphorus they excreted 2.5 times the amount of total phosphorus and twice the amount of WEP. Therefore both of these studies leads us to conclude that overfeeding horses phosphorus is not necessarily detrimental to the horse, but could be detrimental to the environment.

Stable Management: Well-ventilated stables are necessary for horse health. Ventilation involves air exchange, where stale air is replaced with fresh air, and air distribution, where fresh air is available throughout the stable (Wheeler et al, 2003, 2005). Proper ventilation must provide both for adequate ventilation without the occurrence of a draft. In an equine stable, providing 4 to 8 air changes per hour will help to reduce mold spore contamination, minimize condensation, and reduce moisture, odor, and ammonia accumulation. Natural ventilation is used in horse stables and the openings located along the sidewall and ridge (roof peak) are used to accommodate these air movement forces. The other major type of ventilation is mechanical ventilation, which uses fans, inlets, and controls in a pressure controlled structure (Webster et al., 1987; Wheeler et al, 2003, 2005). Proper ventilation can decrease respiratory problems and inhibit dust accumulation, molds and other air contaminants.

Ammonium-N is highly volatile, able to enter the air in gaseous form. Nitrates and ammonium-N can have negative implications on air and water quality, with potential to cause stark ecological changes harming biodiversity (Koelsh, 2003). Ammonia emmissions (kg/LU (Livestock Unit 500kg live weight)) is predicted to be lower in horses than in cattle, pigs, poultry, or sheep (reviewed in Hartung and Phillips, 1994), yet ammonia emitted by horses is no less able to impact the environment on a unit by unit basis. Ammonia contamination has the potential for at least short-term adverse effects on agricultural workers involved in animal care (Greger and Koneswaran, 2010; Schiffman et al., 2005).

Environmental ammonia is another growing health risk for animals confined indoors (Sweeney et. al., 1989). McMillan in 1986 reported that aerial ammonia in horse stalls can be a predisposing cause of foal pneumonia, and certain natural defense mechanisms of the horse's respiratory system can be inhibited by exposure to aerial ammonia.

Ways of controlling environmental ammonia include adequate ventilation in equine housing and daily stall cleaning (Wheeler et al, 2003, 2005). Other measures of controlling environmental ammonia accumulation may be through the use of optimal bedding materials and/or the use of ammonia absorbing compounds, 33. Tanner et al, 1997, found that paper bedding was effective in managing environmental ammonia when combined with daily stall cleaning. More research is needed on the air quality in horse housing especially in establishing the level at which aerial ammonia will have a detrimental effect on the health of the horse.

Air quality is sampled for quality by using an Andersen Cascade Impactor for analyses for airborne GNB and fungi in the stalls using the N-6 plate technique (Jones et al, 1985).

Dust exposure is associated with adverse health effects in both animals and humans. A major health concern in stabled horses is the occurrence of chronic obstructive pulmonary disease (COPD). Chronic obstructive pulmonary disease, also known as heaves or broken wind, has been associated with poorly ventilated stables, exposure to dust, and as a sequel to bacterial and viral respiratory tract infections (McPherson and Thomson, 1983). Previous studies have shown equine COPD to be a pulmonary hypersensitivity to organic dust antigens in the environment (McPherson et al., 1978, 1979ab). The quantity, composition and aerodynamic size of respirable dust particles in stable air determines the inhaled dose, antigenicity and the site of deposition in the respiratory tract, respectively (McPherson et al., 1978, 1979ab). One study of airway disease in horses determined that any riding surface, of any material, may eventually result in air pollution with dust and fungal spores, regardless of material (Rapp et al., 1992).

Equestrian riding instructors and trainers are at an increased risk for several respiratory conditions based on research. During riding and training activities, arena surfaces are agitated by the use of one or more horses, resulting in airborne dust. Instructors and trainers are exposed to this dust for many hours daily. Confined or enclosed areas can intensify dust concentrations (NIOSH, 1994). In a Colorado study (Barton, et. al., 2001), the amount of endotoxin contamination in the arena dusts was similar to or higher than those reported to have been associated with the development of pulmonary disease in other work environments. Dusts generated from these riding surface materials are both organic and inorganic in nature and may be a potential health hazard to horses and humans.

In a study (Kollar et al., 2005), the prevalence of symptoms of four respiratory conditions (chronic bronchitis, noninfectious rhinitis, asthma, and pneumonia) was investigated in relation to work exposure, type, and other environmental conditions including dust exposure and smoking. Survey data suggested that both nonsmoker and smoker equestrian instructors (44% vs. 67%, respectively) are more likely to develop bronchitis symptoms if the primary working facility is an indoor arena compared with an outdoor arena. Equestrian instructors appear to be at an increased risk for some respiratory conditions based on these results. Therefore, it is necessary to understand the types of surface materials that are being used in riding facilities. Surveyed riding surfaces were reported to consist of: 71% sandy soils (crushed: shell, limestone, river sand) as a primary surface component, 40% clay soil, 21% wood products (chips, shaving or saw dust), 7% used rubber products and 6% used tan bark. Sands and existing soils were the primary carrying material that was mixed with other arena surface treatments.

The use of dust control agents in barn and riding arenas and the prevalence of bronchitis symptoms were also investigated (Kollar et al., 2005). The primary dust suppression agent used by respondents was water (58%); 7% added chemicals (salts), 6% incorporated soiled bedding/manure, and 3% used other suppressants and 3.2% used other suppressants (tan bark, vegetable oil, petroleum or mineral-based motor oils). Sixty percent of stables have reported using some dust control efforts. In this study, there was no association observed between the prevalence of bronchitis and dust control agent use in indoor arenas. According to these studies, most equestrian facilities operators are concerned about dust control because many equestrian instructors and trainers spend long hours each day in an indoor arena.

Other Best Management Practices: Precipitation can generate significant runoff around horse facilities producing mud. Stormwater management can help reduce non-point source pollution and negative environmental impacts. The installation of gutters, downspouts, and splash blocks on all barns and buildings can reduce mud and pollution. Divert runoff away from paddocks, exercise lots, and stable areas through the use of a properly designed and maintained drainage system. This greatly reduces the amount of mud and water around barns and buildings, and will prolong the life of building foundations and fencing (Bamka, 2004). Provide green belts (grassy areas), swells and other drainage to move and utilize the water and nutrients (Castelle, 1994). Locate buildings and shelters on higher topographic areas with well-drained soils (Bamka, 2004). These BMPs can prevent the potential for manure washing away and will protect the environment.


  1. Examine pasture and grazing management practices on equine farms in order to promote systems that preserve soil, water and environmental quality
  2. Develop suitable manure storage and disposal strategies best adapted to equine farms, particularly focusing on smaller farms (< 20 head per farm)
  3. Better quantify feeding management practices, both dietary nutrient content and feeding practices, in order to determine on manure characteristics and effects on soil, water, and air quality
  4. Study stable and housing facilities to better understand how to improve air and environmental quality, this will include an emphasis on both equine and human environments
  5. Examine other best management practices such as stream crossings, buffer strips, heavy use pads, and sacrifice areas in order to optimize effectiveness
  6. Develop means of determining the impact of equine outreach programs, more specifically determination of BMP adoption rate.


Objective 1: Examine pasture and grazing management practices on equine farms in order to promote systems that preserve soil, water and environmental quality. Tasks 1. Determine differences in environmental impact parameters among the following grazing management systems: intensive rotational grazing, restricted grazing, and continuous grazing. 2. Determine the effect of various horse pasture seed mixes on pasture plant persistence and other environmental impact parameters. 3. Develop pasture best management video clips suitable for posting on YouTube. Task 1 Methodology: The USDA-NRCS Pasture Condition Score criteria will be used to evaluate and compare environmental impact of the following grazing systems during a 60-d period in both the summer and fall. 1. Continuous grazing  Horses will be stocked at 1.5 to 2 ac per horse. 2. Intensive rotation grazing (3.5-d rotation)  Initially, an area of pasture (e.g., grazing cell) will be allocated to provide horses an amount of 3.5 d worth of DM. Horses will be moved to a new grazing cell containing 3.5 d worth of DM every 3.5 d. 3. Intensive rotational grazing (7-d rotation)  A protocol similar to number 2 above will be carried out for 7 d instead of 3. 4. Restricted grazing  Horses will be stocked at 1.5 to 2 ac per horse. Grazing will be restricted to allow a DM intake necessary to meet maintenance DE requirements only according to the equation of Siciliano (2012) and the method used by Dowler et al., (2012). Horses used in this study will have maintenance only requirements and be of similar age and breed. All pasture will contain similar plant composition. USDA-NRCS Pasture Condition Scores will be evaluated in each of the four grazing systems. Overall pasture condition score and individual parameters will be evaluated using analysis of variance to determine differences among the four grazing systems. Task 2 Methodology: Grazing plots containing several pasture plant mixes will be evaluated for persistence. Plant mix composition will be determined based on previously conducted research according to Martinson and Sheaffer (2013). Task 3 Methodology: Based on the outcomes of objectives one and two pasture best management video clips, suitable for posting on YouTube and other similar web-based venues will be developed. Potential topics include: intensive rotational grazing for horses, pasture condition scoring, selecting pasture plant varieties, renovating pasture using plant varieties aimed at improving grazing tolerance and enhancing ground coverage. Objective 2: Develop suitable manure storage and disposal strategies best adapted to equine farms, particularly focusing on smaller farms (< 20 head per farm). Tasks 1. Compare different compost storage methods for how they affect the compost process and water quality; 2. Determine optimum methods for horse manure composting. 3. Examine the use of Near Infrared Spectroscopy as a predictor of horse manure nutrient content 4. Examine the potential of horse manure as an energy source Task 1 Methodology: Two different composting designs will be used to determine influences on environmental and water quality. Horse manure plus different bedding sources will be evaluated from research horses. Manure will be stored on a concrete storage pads or compacted soil pads; composting manure will be turned on a regular basis. Runoff will be monitored to determine nutrient runoff from the compost piles. Following the collections a final compost analysis will be completed to determine compost quality. Soil samples will be taken on the soil pads to determine nutrient buildup. Task 2 Methodology: Determine optimal composting techniques using different types of animal bedding and different turning times upon compost quality and the length of time required for finished compost. A compost analysis will be completed at the end of the study. Using a data logger and sampling probes, compost piles will be monitored regularly for oxygen and temperature; these measurements will be used to make management decisions. Compost project will continue research efforts already in place: windrow composting, off-site disposal, and research comparing different bedding types. Research will result in recommendations about compost storage facilities and composting methods that will be communicated to equine farmers and managers. Task 3 Methodology: Near Infrared Reflectance Spectroscopy (NIRS) is a procedure for the rapid analysis of nutrient content in feedstuffs. It is based on wet chemistry. The near infrared reflectance in a feedstuff is calculated and regressed on the feedstuff nutrient content, based on wet chemistry values. The resulting prediction equations can be used to predict nutrient content from spectral data only. This procedure has not only been used for feedstuffs, but to estimate nutrient in dairy, poultry, and swine manure (Van Kessel and Reeves, 2001; Reeves, 2000; Malley, et al. 2002). We (Rutgers University) have analyzed over 100 samples of horse manure for nutrient content and have also collected NIRS spectral data. We have developed prediction equations. Our next goal is to complete a field study using these prediction equations for determining nutrient content on farm. These predictions could be used in either manure spreading or manure marketing programs. Task 4 Methodology: Horse manure has energy content that compares with that from other species. The addition of high levels of bedding increases the carbon energy content of manure. Previous analysis has indicated that horse manure (with bedding added) averages approximately 4,000 kcal/gram and over 7,000 BTU/lb. Horse manure may have potential for other technologies such as gasification or combustion. Using Near Infrared Spectroscopy (NIR) it is possible to predict nutrient content of horse manure. Near Infrared analysis predicted the gross energy value of fine ground horse manure and course ground horse manure (>100 samples), .90 R-squared and .87 R-squared, respectively. Ash content was also a good predictor of energy content, .96 R-squared. Having demonstrated the energy content of horse manure and two methods for relatively quick analysis, our next goal is to determine its combustion value and potential for widespread use. Objective 3: Better quantify feeding management practices, both dietary nutrient content and feeding practices, in order to determine on manure characteristics and effects on soil, water, and air quality. Tasks 1. To determine the level of excretion in manure of nitrogen, ammonia, phosphorus and water extractable phosphorus 2. Determine the level of ammonia in the air with horses on different feeding programs in different regions of the US. Task 1 and 2 Methodology: Measuring Fecal nitrogen, P and WEP. Several diets will include horses fed a mostly alfalfa diet, low quality grass hay diet, high performance diet with high grain intake and a moderately supplemented diet with grain and grass mix hay. Detailed dietary information will be collected from each horse sampled. Farms will be use from throughout the region and samples will be taken by those involved with the NE-1041 project. Manure samples will be collected from fresh manure (either from the stall or paddock), frozen and shipped frozen to the laboratory (TBA). All samples will be analyzed from the same laboratory. Data will be compiled and an excretion model will be made based on dietary information. Ammonia samples will be taken from the individual farms in the barns, stalls, and cleanout areas (see Objective 4 below). Objective 4: Study stable and housing facilities to better understand how to improve air and environmental quality; this will include an emphasis on both equine and human environments. Tasks 1. To determine ammonia air production in horse stalls in barns with different management schemes across different regions in the US. 2. Determine means of comparing dust and allergens on cooperating farms. Task 1 Methodology: Ammonia measurement. Ammonia production released into the air will be measured by a Drager tube located on the horses halter for a period of 8 hours while they are in an unbedded stall. (A Drager tube is an ammonia monitoring system. [Draeger Safety Inc. 101 Technology Drive Pittsburgh, PA 15275-1057.] Ambient air is collected in the tube and reacts with chemicals in the tube. The degree of color change provides the concentration.) Another Drager tube will be used in the isle of the barn and in a selected number of stalls (a representative number) 1 m above the ground, 1 L of air inspired to give a per L reading of ammonia prior to stall cleaning. Detailed dietary information will be recorded for each horse used and each farm participating. Volunteer farms from around the region in the participating NE-1441 states will be asked to participate in the study. Those participating in the NE1441 project will be asked to collect the data, both management survey and Drager tube readings. Objective 5: Examine other best management practices such as stream crossings, buffer strips, heavy use pads, and sacrifice areas in order to optimize effectiveness. Tasks 1. To compare manure storage base materials and buffer length and grass characteristics when runoff is diverted into a vegetative area. 2. Survey across the NE-1441 region to determine the use of various best management practices related to the environment and water quality. Task 1 Methodology: Using several manure storage areas with either a concrete or a compacted earthen pad (Objective, Task 2), runoff will be collected and diverted into buffer areas that can be used to collect manure runoff. Buffer areas will be compared to determine ability to control runoff. Task 2 Methodology: A survey will be taken in all NE-1441 participating states to determine the use of the following best management practices: managed storage area, composted manure storage, stream crossings, buffers and vegetative filter strips, heavy use pads and sacrifice areas, soil testing, and fertility management on fields receiving manure.

Objective 6: Develop means of determining the impact of equine outreach programs, more specifically determination of BMP adoption rate.

Task: This will allow us to chart progress among producers who use extension services and/or implement BMP's with the assistance of extension or other service providers such as NRCS, state departments of agriculture, and etc. We will work with social scientists to determine adoption rates, what are the reasons for resistance to adoption, and how to develop programs to overcome this resistance. At our fall 2014 meeting we will discuss how we can begin to implement this objective.

Measurement of Progress and Results


  • Research recommendations for appropriate grazing systems to improve water and environmental quality
  • Improved variety and pasture mix recommendations to improve stand heatlh and soil quality under different grazing systems (continuous, rotational, etc.)
  • Develop improved manure composting recommendations appropriate for small horse farms
  • Validate the use of Near Infrared Spectroscopy for the analysis of horse manure to rapidly determine nutrient and energy content
  • Determine the level of nutrient excretion on different diets fed routinely on horse farms
  • Determine the level of ammonia present in horse barns, stables, and in manure storage areas when different diets are fed
  • Determine best management practices for construction and managing manure storages
  • A completed survey of best management practices implemented in NE-1441 participating states

Outcomes or Projected Impacts

  • Increased availability of equine appropriate pasture mixes for different grazing management situations
  • Increase the use of sacrifice areas as an indicator of good rotational or intensive grazing management
  • Increased use of composting determined by an improved understanding of what does and doesn't constitute composting
  • Development of a composting protocol that is easily applicable on small farms
  • Improved hay feeding recommendations for reducing nitrogen excretion
  • Application and use of Water Extractable Phosphorus or WEP to determine phosphorus runoff risk in manure
  • Recommendations for the reduction of ammonia in barns and stables
  • Completed survey results about the application of different best management practices on horse farms
  • Increased use of vegetated areas around manure storages and dry lots


(2015): 1. Design pasture management protocols for comparing different systems (rotational, intensive, continuous, etc.); 2. Establish pasture mixes for grazing wear and persistence studies; 3. Complete compost research area; 4. Complete NIRS calibrations; 5. Write survey to be used in NE-1041 participating states

(2016): 1. Initiate grazing and pasture mix persistence studies; 2. Begin comparing compost storage methods; 3. Begin field study of manure nutrient content using NIRS; 4. Feeding studies using different practical equine diets; 5. Set up monitoring experiments at participating horse farms; 6. Evaluate buffer lengths for runoff from horse manure storages

(2017): 1. Continue grazing and wear studies; 2. Continue compost studies; 3. Analyze horse manure as an energy source; 4. Finish and summarized manure nutrient content calculated by NIRS field study; 5. Continue feeding studies 6. Begin ammonia monitoring studies on horse farms; 7. Begin administering survey about best management practice utilization

(2018): 1. Complete and summarize grazing management and wear persistence studies; 2. Evaluate covered and uncovered manure piles and concrete vs. dirt pads for manure composting; 3. Develop recommendations for using NIRS to determine manure nutrient content; 4. Complete and summarize feeding studies; 5. Continue ammonia monitoring studies on horse farms; 6. Complete and begin summarizing survey data

(2019): 1. Complete and write materials about grazing and pasture management; 2. Complete compost and related best management practice (buffer lengths) studies; 3. Develop a pilot project for use of horse manure as a combustible energy source; 4. Make practical recommendations about ammonia management in barns, stables, and in stalls; 5. At the completion of feeding studies, begin to summarize and determine what research is yet needed; 6. Summarize best management practice survey and use for educational purposes and to determine future research and education programs

Projected Participation

View Appendix E: Participation

Outreach Plan

The NE-1041 project cooperated with eXtension Communities of Practice (COPs) the Livestock Poultry Environmental Learning Center (LPELC) and HorseQuest. We participated in the LPELC Waste to Worth conference in 2013.

We provided content to these groups and will continue to do so. In April of 2015 we will again participate in the Waste to Worth Conference. Some of our members are part of the planning committee and we will sponsor an equine environmental program at the meeting which will include plenary talks, oral papers and posters. In addition we will sponsor a tour for attendees. The Waste to Worth attracts not just research professionals, but is attended by extension specialists and agents, industry professionals and farmers. There are international guests as well. This is an excellent opportunity to highlight the group and present our work.

The equine team members will continue to use our research work to produce curricula in conducting more workshops, training other educators, and assuming leadership roles in implementing and evaluating our state and regional programs. Some of our outreach plans include:
1. As part of our annual meeting we will continue to produce a ½ day meeting for horse producers in the locale of that years meeting. We will use our most recent research in preparing our talks. We have done that at several of our recent meetings (Minnesota in 2010; Vermont in 2012; and Penn State in 2013). We will do this at each of our annual meetings. We will also consider the possibility of doing these meetings by webinar to reach more producers with the latest in equine environmental information.

2. Produce a regular series of webinars for outreach. This can also include outreach to research and extension professionals who are not members of NE-1441. This could raise our visibility and help to recruit more membership to our group.

3. Develop a project website that will allow us to disseminate project information and can also be used for recruitment. A Facebook page may also allow us to do this. We will discuss among our group how to pursue on this and we may have to get some outside assistance.

4. We will continue to produce content and make it available to the public by eXtension as well as our individual state experiment stations.

5. An outline composting course developed by Rutgers University will be disseminated using this group and other resources. Producers and others will be informed about its availability.

6. Produce quarterly articles for a lay publication such as The Horse on topics on environmental management of farms.

7. The team will continue to work with demonstration farms on BMP development.

8. Video clips, suitable for posting on YouTube and other similar web-based venues, will be developed. Topics will be developed from our research programs.


This regional project NE-1041 was initiated by Rutgers University and the New Jersey Agricultural Experiment Station.

The following are the current members of the project:

Bott, Rebecca C., South Dakota Cooperative Extension

Burk, Amy O., Maryland Cooperative Extension

Gladney, Laura B., New Jersey - Rutgers University

Greene, Elizabeth A., Vermont Cooperative Extension

Hashemi, Masoud, University of Massachusetts

Herbert, Stephen J., University of Massachusetts

Katz, Michael, University of Massachusetts

Komar, Stephen J., New Jersey - Rutgers University

LeBlanc, Brian D., Louisiana Cooperative Extension

Malinowski, Karyn, New Jersey Cooperative Extension

Martinson, Krishona, Minnesota - University of Minnesota

Nadeau, Jenifer A., Connecticut Cooperative Extension

Obropta, Christopher, New Jersey - Rutgers University

Siciliano, Paul D., North Carolina - North Carolina State University

Splan, Rebecca K., Virginia Polytechnic Institute and State University

Swinker, Ann M., Pennsylvania - Pennsylvania State

Trottier, Nathalie, Michigan - Michigan State University

Wagner, Elizabeth L., Alabama - Auburn University

Westendorf, Michael, New Jersey - Rutgers University

Williams, Carey A., New Jersey - Rutgers University

In addition the following individuals at Rutgers University or other institutions have been involved in Equine Environmental and Management Research:

Foulk, Donna, Extension Educator, Pennsylvania State University

McKernan, Helene, Extension Assistant, Pennsylvania State University

Gimenez, Daniel, Ph.D., Department of Environmental Science, Rutgers University

Maenelis, Gedi, Ph.D., Department of Environmental Science, Rutgers University

Murphy, Stephanie, Ph.D., Soil Testing Laboratory, New Brunswick, NJ, Rutgers University

Sciarappa, Bill, Ph.D., County Agricultural and Resource Management Agents, Rutgers University

Bamka, Bill, County Agricultural and Resource Management Agents, Rutgers University

The recommended Standard Governance for multistate research activities including the election of a Chair, a Chair-elect, and a Secretary. All officers will be elected for at least two-year terms to provide continuity. Administrative guidance will be provided by an assigned Administrative Advisor and a CSREES Representative. As of this date, Michael Westendorf, Rutgers University, has been serving as chair and will continue so until the initiation of the next project.

Subcommittee/research teams will be chosen from the objective areas:

1. Examine pasture and grazing management practices on equine farms in order to promote systems that preserve soil, water and environmental quality

2. Develop suitable manure storage and disposal strategies best adapted to equine farms, particularly focusing on smaller farms (< 20 head per farm)

3. Study stable and housing facilities to better understand how to improve air and environmental quality, this will include an emphasis on both equine and human environments

4. Better quantify feeding management practices, both dietary nutrient content and feeding practices, in order to determine on manure characteristics and effects on soil, water, and air quality

5. Examine other best management practices such as stream crossings, buffer strips, heavy use pads, and sacrifice areas in order to optimize effectiveness

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