Final Report for LS11-245
Based on the results of the baseline studies of pastured poultry farms, most pasture-raised broilers processed on-farm, in a small United States Department of Agriculture Inspected slaughter facility (USDA-IF), and in a Mobile Processing Unit (MPU) pilot plant methods were contaminated with Salmonella and/or Campylobacter. These pathogens were highly prevalent in wastewater, soil, and compost resulted from broiler processing on-farm. The MPU has a good economic feasibility and it is a competitive alternative to the traditional on farm processing option.
1. Assess the food safety risk (concentrations of foodborne pathogens) on pasture poultry chicken carcasses processed using MPU compared to traditional on-farm processing and chicken processed at a small volume USDA facility.
(Leader-Alali; Co-PIs: Ricke, Jaroni, Gibson, C. Owens)
2. Assess the biosafety risk of pathogens in waste disposal (wastewater and solid waste) of poultry processing (MPU vs. on-farm) on the environment.
(Leader-Gibson; Co-PIs: Ricke, Crandall, Jaroni, Sharpley, Alali, C. Owens)
3. Evaluate the economic feasibility of MPU for pasture farmers as a potential source to increase poultry products marketability. Furthermore, pasture poultry farmers in Georgia, Arkansas, and Louisiana will be surveyed to evaluate their interest and willingness to process their birds in MPU.
(Leader- Kostandini; Co-PIs: Van Loo, Welander, C. Owens)
4. Assess the consumers' willingness to pay for pasture chickens compared to USDA certified-organic chickens in the three states using 'consumer experiments'.
(Leader- Van Loo; Co-PIs: Ricke, Crandall, Alali)
The purpose of this project was to assess the food safety risk, environmental impact of waste disposal, and economic feasibility of pasture poultry processing using Mobile Processing Units (MPU) in the Southeast of the U.S. The demand for locally produced food in the U.S. continues to grow. According to a report by the USDA-Economic Research Service (ERS), there is a sustained consumer demand for locally grown food (King et al, 2010). The demand for locally grown food in the U.S. is expected to increase to about $7 billion by 2012 up from $4 billion in 2002 (Martinez et al., 2010). Under the 2008 Farm Bill, USDA has increased the focus on small and mid-size farms, encouraging projects to enhance locally grown food (fresh produce and meats) production and marketing to consumers, and launching what is known as "Know Your Farmer, Know Your Food" program.
Pasture poultry farms are small operations (average of 1,500 broiler birds raised per year) where chickens are reared on pasture in open-air moveable pens or completely free range (Jacob et al., 2008). Pasture birds are grown without subtherapeutic (growth promotion) or therapeutic antimicrobial use (i.e., considered as antibiotic-free chickens), and usually fed non-USDA-certified organic diet. The USDA has placed a set of national standards, the broiler production must meet, to be labeled “organic” (Dimitri and Greene, 2002). These standards are primarily: 1) birds must be raised without the use of antibiotics, 2) fed organic dietary supplements, consume all organic feed free of animal by products, 3) feed ingredients are from organic farms (e.g., organic corn), and 4) birds have access to the outside environment (Dimitri and Greene, 2002).
Pasture poultry farmers are at a disadvantage when it comes to marketing their locally produced chickens. Pasture poultry is mostly processed on-farm or in small facilities exempted from federal inspection. Farmers that kill and process < 20,000 bird/year are federally exempted from USDA inspection. Due to this exemption, pasture poultry sales have been limited to household consumers and very few market venues (e.g., farmers' markets, restaurants, hotels). Small volume USDA processing facilities within a reasonable driving distance to farmers are lacking in many states. Many farmers realize that long-distance transportation is stressful to birds which may have an impact on the quality and safety of their product. On-farm processing is labor-intensive, and time consuming, which therefore limits the number of birds that can be processed per week and subsequent production volume and profitability. The MPU initiative, as a potential USDA inspected facility, is being discussed by pasture poultry farmers, pasture poultry working groups, and “buy local”/organic non-profit organizations. Having USDA-inspected chicken products will eliminate regulatory impasses, increase market venues and consequently sustain farmers' profitability. Farmers will then be able to sell their USDA-inspected chicken products without restriction to all potential customers.
The USDA-FSIS has recently released a recommendation guide “Mobile Slaughter Unit Compliance Guide” intended for MPU owners and managers who want their unit to be federally inspected in accordance with FSIS regulations (USDA, 2010a). Due to the lack of data on both, food safety risks of chicken processed in MPU and the environmental impact of waste disposal, this FSIS guide recommended assessment of food safety that relates to the MPU processing and resulting products, and assessment of the impact of waste disposal on the environment.
In a recent meeting organized by Georgia Organics (Rolls, Owens, and Welander) in August 2010, ten pasture poultry farmers from Georgia participated in the meeting and shared their views and concerns on the poultry processing issue. The PI (Alali) attended the meeting and presented an overview of food safety assessment needs in pasture chicken products. Farmers were highly interested in the food safety assessment in addition to the environmental impact of waste disposal for two main reasons: 1) how safe is their product (i.e., food safety risk) compared to conventional chicken products and whether waste disposal (wastewater and solid waste) have an impact on their farm land and underground water, and 2) data on product safety will support the farmers legal issue with the State of Georgia to support the creation of rules and regulations permitting safe and legal processing in the state of Georgia.
Early input for this proposal came from a symposium organized by Co-PI (Ricke) and University of Arkansas Poultry Extension specialist, Frank Jones, entitled “Current and Future Prospects for Natural and Organic Poultry” at the 2008 Poultry Science Association annual meeting held in Niagara Falls, Canada. Several issues such as food safety, the need for better antimicrobials, economical viability and marketing were highlighted as key areas that needed further research. In a follow-up to this symposium, Co-PI Ricke in conjunction with Poultry Extension specialist Jones conducted a NW Arkansas pasture flock poultry farmers workshop in Eureka Springs, AR where issues such as the shortage of available local poultry processing facilities and comprehensive outreach information were identified as acute needs for a local pasture flock industry to flourish.
Collaborating institution (Co-PI, Jaroni), the Southern University Agricultural Research & Extension Center (SUAREC), also serves pastured poultry farmers as one of their clientele groups and has conducted several workshops and extension activities to educate the pastured poultry farmers of Louisiana. One of the workshops held recently at SUAREC titled, “Sustainable Broiler Production and Marketing Enterprise”, focused on the issues of small-scale pastured poultry and was attended by several small-scale poultry farmers in Louisiana. These farmers, who mostly harvest and process their birds on-farm, have shown extreme interest in improving the safety and profitability of their products that are mostly sold at the farmer's market or to local consumers. Some of the farmers have also started following a processing model (non-mobile processing unit) suggested by SUAREC extension.
Investing farmers' money in a sustainable MPU also requires that chicken products are cost-effective, economical, and profitable to producers. Small-scale poultry producers (process fewer than 20,000 birds per year) would want to know whether federally-inspected MPU is an economical alternative for processing their birds compared to on-farm or processing at small-volume facilities. In a survey conducted by project participant (Welander) to evaluate the processing infrastructure in Georgia, found that 52% (out of 61) of the surveyed farmers indicated an interest in processing over 20,000 chickens per year on-farm. Only 15% of the farmers want to exclusively process on-farm, while other farmers are open to alternative processing methods including MPU.
The federal law exempts farms processing less than 20,000 birds from inspection. However, state laws may not allow this exemption. In Arkansas, the federal law is followed, allowing farms to be exempt from inspection if less than 20,000 bird/year are processed. However, in the other participating states, the state laws are stricter. The Louisiana state law requires inspection of facilities for sanitary conditions that process fewer than 20,000 birds. The processing facility has to follow the federal regulations on sanitary condition for processing birds for human consumption. In addition, pasture chicken products can be distributed only within the state of Louisiana. Georgia is another participating state disallowing the federal exemption.
The US poultry industry is strongly vertically-integrated including production and processing, resulting in few processing plants available to the small-scale, independent farmers. For small-scale poultry farms, the USDA inspected processing facilities in place for conventional poultry operations are off-limit (Welander, 2010). They have two options: either process their chickens in a sanitary way on their own farms or take them to smaller volume processing facilities that serve small-scale farmers. There are not many processing facilities available that are designed for those very small batches of poultry. We suggest that a MPU processing unit, shared by the farmers, would be the perfect way to provide them with a sanitary method for the on-farm processing.
Validation of consumers WTP (Willingness To Pay) for pasture poultry products and the factors that influence their decision will feedback directly to pasture poultry producers to better assess their products marketability and production cost. Consumers view organic meats, in general, as safer and healthier alternative to conventionally-produced meats mainly due to the perception of organic meats as higher quality, more nutritious, and antibiotic free (Krystallis and Chryssohoidis, 2005; Krystallis et al., 2006; Winter and Davis, 2006). According to a study by Van Loo et al. (2010b), the consumer's WTP for organic chicken was affected by the type of label. Overall, consumers indicated they would be willing to pay 34.8% extra for an organic label and 103.5% extra for an USDA certified organic label. This indicates a difference in WTP depending on the type of label. The frequency of buying organic meat had a significant influence on the WTP with habitual buyers indicating willingness to spend 146.6% and 244.3% extra for organic and USDA certified organic label respectively indicating a huge market potential for these types of products. Consumer's organic poultry products purchases were influenced by various factors such as price, availability of the products, satisfaction with conventional chicken products, quality of the product, and whether products contain antibiotic residues Van Loo et al. (2010b). Furthermore, other factors such as household income, ethnicity, and education level were not significantly associated with consumption of organic chickens. Interestingly, Van Loo et al. (2010a) reported that 35% of habitual organic meat consumers/buyers 'neither agree or disagree' that organic meat products are less likely to be associated with food poisoning compared to conventional meat products. This figure was a little higher for occasional and non-buyers of organic meats with 49% and 44% 'neither agree or disagree', respectively. This suggests that consumers don't know which meat products (organic vs. conventional) are actually safer. Data on food safety risk of conventional chicken products is available in the literature and in FSIS quarterly and annual reports. However, data is limited on food safety risk associated with pasture poultry chicken products. Our proposed study will focus on the small-scale (family farm) pasture poultry producers and their products. We anticipate the information generated from this study will be paramount to sustainability of pasture poultry producers.
In summary, we propose to use a more holistic approach to assess food safety risk, environmental impacts of pasture poultry processing methods, and economic feasibility of MPU compare to other methods in the Southeast. None of the SARE-funded projects reviewed here addressed the multiple components of our proposal in a system approach that circumvent the most crucial issues surrounding the MPU initiative for pasture poultry farmers in the Southeast. The sustainability of pasture poultry production is critical to: 1) the farmers and their families (economically), the environment where production causes no adverse effect (i.e., environmentally friendly), and 3) the local communities that buy locally produced chickens. The research findings will be made available through workshops, seminars, in-print, training programs for pasture poultry farmers and the scientific communities.
Study Design and Sampling Scheme
Over a one year period, this study was conducted at independent, small-scale pasture-raised broiler farms that processed birds at the site of production (on-farm), at the small USDA-IF or at an MPU pilot plant in the southeastern region of the United States. The participating farmers produced approximately 1,000 broilers per year. Samples were collected during 12 on-farm visits in accordance with the farmers’ broiler processing schedules. One producer raised and processed Cornish Cross breed broilers, while the other three producers used slower-growing breeds (i.e., Freedom Rangers and K-22). Ten sampling visits were conducted between two small USDA-IF and five processing runs were conducted at the MPU pilot plant. At each visit to the farms that processed birds on-farm, at the USDA-IF, and during each MPU processing run, 10 post-chill broiler carcasses were randomly selected and rinsed using the USDA whole carcass rinse method.
Birds were processed manually on the farm in an open-air setup or at a processing station in an enclosed shed. Processing stations included kill cones, a single-stage static scalder, a mechanical batch picker, stainless steel tables for evisceration, a water hose for spray washing carcasses, and large containers filled with ice water as a chill tank. The two small USDA-IF were located in rural areas of the southeastern United States. Both were equipped to process small batches (less than 500/day) of pasture-raised broilers from independent producers. Pasture-raised, slow-growing Red Rangers and Cornish Crosses were processed at these facilities. A batch processing system was used and most of the processing was performed manually by employees of the establishments. Antimicrobial interventions for pathogen control included treatment of carcasses with a citric and lactic-acid based antimicrobial spray. Carcasses were chilled in a chill tank filled with ice water. Processed birds were inspected by a USDA-FSIS employee.
The University of Arkansas (UA) Poultry Science Department MPU pilot plant was located at the UA-Agriculture Experiment Station in Fayetteville, AR. Pasture-raised broilers were delivered to the facility by local farmers and were processed on the same day. Breeds included Ross 708, Cobb 700, Freedom Rangers and Naked Necks. The batch processing system consisted of a killing tunnel, 5 SHC-16 shackles, a 5A140 scalder with attached PDK Dunkmaster immersion unit, a JS-2A Spin-Pik picker and a chill tank. All MPU components were manufactured by the Pickwick Company (Cedar Rapids, IA). Birds were stunned and killed with a hand held electric stun knife and were allowed to bleed out for 2 to 5 minutes. After scalding and defeathering, evisceration was performed manually with scissors and gloved hands. No antimicrobial interventions were used during MPU processing. Carcasses were chilled in chill tanks filled with ice water.
Pasture-raised broiler carcasses were removed from the chill tank after 1 hour of immersion chilling, then each carcass was placed into a sterile poultry rinse bag (Nasco; Fort Atkinson, WI) and 400 ml of sterile water was poured into the cavity. The carcass was rinsed for 1 minute using a rotating arc motion as described in the USDA-FSIS method. The rinsate was aseptically drained from the rinse bag into a sterile field bottle (Nalgene, Rochester, NY) and was placed on ice for transport to the laboratory.
Analysis for Salmonella and Campylobacter
All samples were processed and assayed on the day of collection using the 3-tube Most Probable Number (MPN) method was used for quantification of Salmonella according to USDA-FSIS methods.
The direct plating and enrichment method was used for detection and enumeration of Campylobacter. to USDA-FSIS methods..
The outcomes of the study were the prevalence and concentrations of Salmonella and Campylobacter on pasture-raised broiler carcasses. The concentration data (MPN or CFU/ml) were adjusted to the original rinse volume (400 ml) and were log10 transformed to approximate normality. The prevalence data were cross-tabulated and compared by processing method (on-farm, USDA-IF, and MPU), followed by a comparison of breeds within each processing method using a Fisher’s exact test or 2-by-n likelihood ratio chi-square test in STATA software version 10.1 (Stata Corp., College Station, TX). The relationship between the pathogen prevalence on the carcasses and the pastured broiler processing method and breed (within each processing method) was assessed using a generalized linear model, with binomial error distribution, logit link function and adjustment for dependency within farms using generalized estimated equations (GEE) in STATA. For pathogen concentration data, the relationship between the log10 MPN or CFU/carcass and the broiler processing method and breed (within each processing method) was assessed using the GEE model, with identity link function to adjust for dependency within farms in STATA. A p-value less than 0.05 was considered significant.
Over a one year period, this study was conducted at 4 small-scale, independent, pasture-raised broiler farms in the southeastern United States. The farms were selected based on the farmers’ willingness to participate in the study (convenience sampling) and participation was based on the condition of privacy. All of the participating farms were exempt from federal and state inspection. Approximately 1,000 broilers were produced per year at each small-scale operation and birds were manually processed at the site of production (on-farm) as described above. Birds were slaughtered at 9 to 10 weeks of age and were processed in a processing station located in an open-air set up or in an enclosed shed. A total of 46 composite processing wastewater (PWW) samples, 42 composite soil samples, and 39 composite compost samples were collected during 12 on-farm visits in accordance with the farmers’ broiler processing schedules. Three visits were conducted at Farm A, 2 visits were conducted at Farms B and C, and 5 visits were conducted at Farm D.
Sampling Scheme and Processing
Farmers processed between 50 and 100 pasture-raised birds at each visit. The processing wastewater from the scalder, picker and runoff from the evisceration table emptied directly into the soil surrounding the processing area. Processing offal was collected and added to an on-site mortality compost pile which utilized the passive composting method (USDA-NRCS, 2010). Compost ingredients included a mixture of manure from farm animals (i.e. goats, pigs, cows), wood chips or straw, dead birds and other small animals. The approximate age of the piles ranged from 6 months to 2 years old.
Samples were collected before processing began at each farm visit. Three separate areas subjected to previous wastewater disposal in the soil were chosen using the judgmental sampling approach(IAEA, 2004). In most cases, previous wastewater disposal occurred at least 1 week prior to sample collection. Sampling points included the areas around the scalder discharge hose, the picker, and the evisceration table. Three 24 cm soil cores (2 cm wide) were collected at each of the 3 disposal areas using a soil auger. Samples were placed in Whirl-Pak® bags (Nasco, Fort Atkinson, WI) on ice for transport to the laboratory where they were combined into 3 composite samples (approximately 100 g each).
Three 30 to 40 g samples in each of 3 areas of the mortality compost pile were collected at each farm visit. A large sterile metal scoop was used to collect the samples at a depth of 24 to 36 cm. Samples were placed in sterile Whirl-Pak® bags on ice for transport to the laboratory where they were combined into 3 composite samples (approximately 100 g each).
Three composite processing wastewater (PWW) samples (1,000 ml each per 10 to 20 birds processed) were collected into sterile plastic field bottles (Nalgene, Rochester, New York) upon emptying of the scalder, picker and during runoff from the evisceration table. Samples were placed on ice for transport to the laboratory.
Analysis for Salmonella and Campylobacter
The 3-tube Most Probable Number (MPN) method was used for Salmonella quantification according to USDA-FSIS methods. The direct plating and enrichment method was used for enumeration and detection of Campylobacter.
The outcomes of this study were the prevalence and concentration of Salmonella and Campylobacter in soil, compost and PWW samples associated with small-scale, pasture-raised broiler processing at the site of production. The concentration data (MPN and CFU/ml or g) were adjusted to the original sample volume or weight collected and were log10 transformed to approximate normality. The relationship between the pathogen prevalence and the sample type (soil, compost and PWW) was assessed using a generalized linear model with binomial error distribution, logit link function and adjustment for dependency within farms using generalized estimated equations (GEE) in STATA software version 10.1 (Stata Corp., College Station, TX). For pathogen concentration data, the relationship between the log10 MPN or CFU per sample and sample type was assessed using the GEE model in STATA, with identity link function to adjust for dependency within farms. A p-value less than 0.05 was considered significant.
Methods, results, and impact are under the Economic analysis section (below).
This objective was not completed due to the following the reasons: 1) the lead participant (Ellen Van Loo; Research Associate) of University of Arkansas has moved to another job outside of the United States, 2) University of Arkansas Co-PIs (whom had the budget to conduct this work and has the expertise) have failed to accomplish the work required to carry on the proposed survey.
The original planned work as in the proposal:
A product label is a quality signal for the consumer and is an important tool to help consumers identify specific attributes of products and help differentiate products. According to Yiridoe et al. (2005), product labels can help buyers assess product quality by transforming credence characteristics into search attributes. Depending on the information present on the product label, consumers are willing to pay a different price. Consumer preferences and WTP for certain food attributes are important for food producers and processors as well as policy makers. The consumer's WTP for different attributes will be evaluated with the use of a choice experiment. In choice experiments respondents are asked to make repeated choices between alternatives described by varying attributes. It is an established approach for understanding and predicting consumer trade-offs and choices in marketing research. Individuals are asked to choose their preferred alternative amongst hypothetically constructed scenarios, where each scenario is a function of different attributes of product (including price) and each attribute varies at different levels. The attributes considered in this study include a label for type of production with levels “all natural”, “USDA organic”, “naturally raised”, “free-range” or "pasture" no production label. However, a lot of consumers are confused about these different production labels. USDA organic label implies that the product meets all USDA organic requirements for production, handling, and processing and is the most strict production label. This standard includes: outdoor access for the livestock, 100% organic feed (so no genetically modified feedstock) and no antibiotics or hormones (Baier, 2010; Fanatico, 2008; USDA, 2010c). “All-natural” label implies that no artificial ingredients or color are added to the product or to the feed (USDA-FSIS, 2006). To meet the "naturally raised" standard, the livestock has to meet the following three requirements: be raised entirely without growth promoting chemicals (1) and antibiotics (except for ionophores used as coccidiostats for parasite control) (2), and have never been fed animal (mammalian, avian, or aquatic) by-products (3) (USDA-AMS, 2009). Poultry products are allowed to be labeled as “Free-range” when allowed to access to outdoors (USDA-FSIS, 2006). With a natural food industry estimated to be 5 times larger than the organic food industry (Keefe, 2010), it is very important to evaluate the WTP for natural food labeling comparative to organic food and conventional food. Another attribute is the location of the banner “locally produced” label if present. As last attribute, an inspection label “USDA inspected” will be evaluated. Consequently, in this choice experiment, we ask respondents to make trade-offs between price, production, location and inspection label. In addition to the choice experiment questions, the subjects will also complete a short questionnaire on attitudes and perceptions towards chicken production and processing as well as some demographic questions.
Consumers from a consumer database in each of the participating states will receive an e-mail invitation with a link to this on-line survey. As incentive, cash price drawing will be done 1 month of completion of the data collection. As indicated by a similar study done at the University of Arkansas (Van Loo et al, 2010b), more than 900 consumers responded to the survey. Our goal would be to have at least 300 consumers filling out the survey in each state.
Data will be analyzed by 2-way ANOVA to test the difference between questions asked to consumers and multivariable regression analysis to shed light on the characteristics of demand for pasture chicken. The three research institutions (UGA, UARK, and SUAREC) and will be involved in this objective. Farmers will be invited to evaluate the progress of this objective's findings and offer suggestions.
The current study established an initial record of quantified Salmonella and Campylobacter populations on pasture-raised broiler carcasses processed on-farm, at small USDA-IF, and in a MPU pilot plant. A total of 120, 100, and 50 carcass rinse samples were tested from small-scale pasture-raised broiler farms, the small USDA-IF, and the MPU pilot plant, respectively.
Salmonella on Pasture-Raised Broiler Carcasses
The Salmonella prevalence and mean log MPN concentration on chicken carcasses by processing method is shown in Table 1. The distribution of the mean log MPN concentrations of Salmonella in carcass rinses is shown in Figure 1. The Salmonella prevalence and mean log MPN per carcass was significantly different (P <0.05) between the processing methods.The prevalence of Salmonella in birds processed on-farm and the small USDA-IF in the current study is relatively greater than data reported in previous studies. Lestari, Han, Wang, & Ge (2009) reported 20.8% of national-brand organic broiler carcasses (n=53) examined from 7 chain grocery stores in Louisiana were Salmonella-positive. Moreover, Cui, Ge, Zheng, & Meng (2005) revealed that 61% (n=198) of organic broiler carcasses at retail were Salmonella-positive. In a study by Melendez et al. (2010), 50% (n=36) of pasture-raised broiler carcasses purchased from a natural foods retail store or obtained from a local processing plant were Salmonella-positive.
Salmonella was not detected on carcasses processed by the MPU in the current study. This finding is in agreement with Killinger, Kannan, Bary, & Cogger (2010) which reported a zero prevalence of Salmonella in post-wash, pasture-raised carcasses used as untreated controls (n=60) during MPU processing. Hoogenboom et al. (2008) reported that Salmonella was not detected in the feces of organically raised broilers at nine farms in the Netherlands.
Campylobacter on Pasture-raised Broiler Carcasses
The Campylobacter prevalence and concentration on pasture-raised broiler carcasses is shown in Table 2. The prevalence of Campylobacter on broiler carcasses was not significantly different (P > 0.05) by processing method. The distribution of the mean log CFU of Campylobacter on carcass rinses is shown in Figure 2. Birds processed in the MPU had significantly higher (P < 0.05) Campylobacter concentrations than those processed on-farm and at the USDA-IF.
The prevalence of Campylobacter oncarcasses processed by the MPU may also be due to seasonal effects on the pasture-raised broiler farms. In a one-year study of conventional retail market broilers, Willis Murray (1997) reported that the highest recovery percentage of Campylobacter occurred during June and July of that year, and both months had a 96.7% (n=30) Campylobacter-positive percentage. Furthermore, Stern et al. (2001) reported that the highest prevalence of Campylobacter in fecal samples of 32 broiler flocks was detected during the summer months. In the current study, sampling of all MPU-processed carcasses occurred during the summer months and 83% of on-farm processed carcasses were sampled during the summer months. Although Salmonella was not detected on carcasses processed by the MPU, Campylobacter concentrations were the higher on these carcasses compared to those processed by the other two methods in this study. It is possible that the birds processed by the MPU were not shedding Salmonella around the time of slaughter, but were shedding Campylobacter. In commercial broiler processing, the management practices used to control Salmonella are often of little impact on Campylobacter in the in the same environment due to significant differences in the physiology and ecology of these organisms (Newell and Fearnley, 2003). This may be true for small scale broiler production environments.
The objective of this study was to establish initial baseline data on the food safety of small-scale pasture-raised broilers processed on-farm, in a MPU pilot plant and at small USDA-IF. As a result, we did not evaluate potential management risk factors which may have contributed to the differences in the prevalence and concentrations of the pathogens in birds processed on-farm and at the small USDA-IF compared to the MPU. Furthermore, information on the breeding flocks and practices of the hatcheries associated with the participating pasture-raised broiler farms was not available.
The prevalence and mean log10 concentration of Salmonella and Campylobacter in soil, mortality compost and PWW samples collected from the on-farm processing environment is shown in Table 3. The distribution of the Salmonella and Campylobacter mean log10 MPN and CFUby sample type (soil, compost, and PWW) are shown in Figures 3 and 4, respectively. The Salmonella prevalence and concentrations were not significantly different (P>0.05) by sample type. The prevalence of Campylobacter was not significantly different by sample type, but the concentration of thispathogen was significantly lower (P<0.05) in PWW samples compared to soil and compost samples.
The rate at which poultry waste is applied to land depends on whether the objective is to supply nutrients to the soil or to simply dispose of waste. If utilization of the fertility-related aspects of the waste is the primary focus, the application should be based on the needs of the crop and the characteristics of the waste (Edwards and Daniel, 1992). Additionally, organic poultry processing wastes should be regarded as contaminated with human pathogens unless the wastes have been treated sufficiently (Burton et. al, 2004). In the current study, a common belief among the small-scale producers was that the direct application of raw processing wastewater is innocuous and will greatly increase soil fertility (personal communication with farmers). In many cases, the farmers did not rotate the location of wastewater disposal during subsequent processing days (personal communication with farmers) and disposal occurred in areas of high foot traffic.
Since most soil samples were collected at least 1 week after application of PWW to the soil, the data suggests that between slaughter dates, both pathogens were moderately prevalent and fairly concentrated in the soil surrounding the processing area. The absence of soil management practices such as varying the location of PWW disposal, coupled with the direct application of untreated wastewater to the soil surrounding the processing area may have contributed to the prevalence of Salmonella and Campylobacter in the collected samples.
The prevalence and concentration of Salmonella and Campylobacter in the PWW samples in this study suggest that the untreated wastewater itself represents a hazard, in addition to the soil surrounding the processing area where the PWW has been dumped. It is possible that the pathogen concentration may have been higher if sampling had occurred at the soil surface. High foot traffic, rainfall and other animals are potential vectors in the transmission of pathogens around the processing area.
The data in Figures 3 and 4 suggest that the mortality compost pile may also pose a risk for the dissemination of Salmonella and Campylobacter in the small-scale poultry production environment. In the current study, we did not survey the individual farmers to collect information on practices such as compost recipes (i.e. C: N ratios), aeration or temperature monitoring. All of the participating farms lacked enclosed, structured composting bins and piles were located on the ground near wooded areas or piles of debris. This arrangement may have provided easy access to the compost pile for pests such as rodents, which are considered to be potential vehicles for transmission of enteric pathogens on the farm (Meerburg et. al, 2006).
Educational & Outreach Activities
- Trimble, L. M., W. Q. Alali, K. E. Gibson, S. C. Ricke, P. Crandall, D. Jaroni, M. Berrang. 2013. Salmonella and Campylobacter prevalence and concentration on pasture-raised broilers processed on-farm, in a mobile processing unit, and at small USDA-inspected facilities. Food Control. 34: 177-182.
- Trimble, L. M., W. Q. Alali, K. E. Gibson, S. C. Ricke, P. Crandall, D. Jaroni, M. Berrang, M. Y. Habteselassie. 2013. Prevalence and concentration of Salmonella and Campylobacter in the processing environment of small-scale pastured broiler farms Poul. Sci. 92: 3060-3066.
- Van Loo, E.J., W. Q. Alali, S. Welander, C. A. O’Bryan, P. G. Crandall, and S.C. Ricke 2013. Independent poultry processing in Georgia: survey of producers’ perspective. Agric., Food, Anal. Bacteriol. 3: 70-77
- Davis, M.L., P.G. Crandall, C.A. O’Bryan, G. Kostadini, K. E. Gibson, W. Q. Alali, D. Jaroni, S.C. Ricke, and J.A. Marcy. 2013. Mobile poultry processing units: a safe and cost-effective poultry processing option for the small-scale farmer. J. Appl. Poultry Res. (under review).
- Angioloni, S., G. Kostandini, W.Q. Alali, C. O’Bryan. Economic Feasibility of Mobile Processing Unit for Small Scale Pasture Poultry Farmers. In preparation.
Education and Outreach:
- An invited talk by the International Association for Food Protection (IAFP) to Dr. Alali was given at the “Ecology of Campylobacter and Salmonella in pasture poultry/mixed farm and their control with natural organic antimicrobials” symposium. The title of his talk was “Salmonella & Campylobacter in pasture poultry production system”, Charlotte, NC. July 29, 2013.
- Poster presentation at the Southern Sustainable Agriculture Working Group annual conference by Lisa Trimble (MS Graduate Student) titled “Food and Environmental Safety of Pastured Poultry Processed On-farm, in a Mobile Processing Unit or at a USDA-Inspected Facility in the Southeastern United States”. Mobile, AL.
- Poster presentation at the IAFP annual conference by Lisa Trimble titled “Food and Environmental Safety of Pastured Poultry Processed On-farm, in a Mobile Processing Unit or at a USDA-Inspected Facility in the Southeastern United States”. Charlotte, NC.
- Poster presentation at the annual Center for Food Safety meeting by Lisa Trimble titled “Food and Environmental Safety of Pastured Poultry Processed On-farm, in a Mobile Processing Unit or at a USDA-Inspected Facility in the Southeastern United States”. Atlanta, GA. March 4, 2013.
- Trimble, L.M., W. Q. Alali, M. E. Berrang. Food and environmental safety of pastured poultry processed on-farm, in a mobile processing unit or at USDA-inspected facility in the Southeastern United States. Poultry Science Association, Annu. Mtg., Athens, Georgia, July 10, 2012
- Foodborne pathogens on chicken carcasses and in the environment of pasture poultry production system. UGA-Sustainable Food System Forum, Athens, Georgia, April 18, 2013.
- Foodborne pathogens on chicken carcasses and in the environment of pasture poultry production system. University of Georgia, School of Public Health, Athens, Georgia, February 15, 2013.
- Mobile slaughter units for pastured poultry growers. Sustainable Agriculture at UGA. Fall 2011.
- From Food safety to economics: Processing your chickens for market. American Pastured Poultry Producers Association Newsletter. November/December 2012. Issue 72. Pages: 6-11.
- A concise version of this final report will be shared with Georgia Organics so it can be distributed through theirDirt paper magazine and eDirt.
Objective 1. The prevalence of pathogens on pasture-raised broiler carcasses may be the result of the Salmonella and Campylobacter dissemination on small pasture-raised broiler farms, which may impact the food safety of the products. Based on the results of this baseline study, most pasture-raised broilers processed by the three methods were contaminated with Salmonella and/or Campylobacter with the exception of the carcasses processed in the MPU pilot plant where Salmonella was not detected on carcasses. The prevalence and concentration of Campylobacter contamination were higher and lower for birds processed in the MPU and on-farm, respectively. Carcasses processed on-farm were mostly positive for Salmonella with levels that correspond with the USDA-FSIS nationwide microbiological baseline data collection program for young chickens (USDA-FSIS, 2008b). The current work provides insight into small-scale poultry production practices and provides a record of data which may serve as a guide for future improvement of food safety practices.
Objective 2. These foodborne pathogens were highly prevalent in wastewater, soil, and compost resulted from broiler processing on-farm. Although the practice of letting the processing wastewater flow on the soil to provide nutrients, it certainly can spread foodborne pathogens in the soil and surrounding environment. Furthermore, current compost practices do not seem to control pathogen presence. Therefore, current study provides insight into small-scale poultry production waste disposal practices and provides a record of data which may serve as a guide for future improvement of these practices.
The study examined the economic feasibly of the mobile processing unit (MPU) for pasture poultry. The analysis uses data from a survey of pasture poultry farmers in Georgia, Louisiana, and Arkansas and on a review of published research.
The first part of the analysis utilized budgets to assess the initial investment, the production cost, the processing cost, the selling price, and the profit of the MPU. This was realized by assuming constant returns of scale. The analysis compared the economic feasibility of the MPU to the profit of the on farm processing alternative and the off-farm USDA inspected facility processing option.
The second part examined the economic feasibility of the MPU using a profit maximization approach accounting for variable and fixed cost with respect to three different scenarios: economies of scale, a more intensive use of the MPU, and the incidence of financial costs.
The study of the economies of scales compared the income of a mini MPU (lower initial investment, higher processing cost) to the income of a medium MPU (higher initial investment, lower processing cost). A more intensive use of the MPU is also considered as a source of additional income by leasing the unit to other farmers. The study relates the profit generated by this activity to the off-farm USDA inspected facility processing options.
The financial aspect examined how the payback period and the per-bird profit changes with respect to the number of processed birds per years and the interest rates. The assessment was conducted for a mini MPU and a traditional MPU.
The results indicated that the MPU profit is, on average, on the same scale with the on farm stationary plant processing system and, generally, lower than the off-farm USDA inspected facility processing option. The per-bird profit is $7.77 and $7.78 for the MPU and the on farm stationary plant option, respectively. The estimated profit of the off-farm USDA inspected facility processing alternative was $11.20 per bird. The profit differences are due to the selling price rather than cost. On average, the per-bird selling price is $3.03 bigger if the product is processed at the USDA inspected facility than if it is not. Instead, the per-bird cost difference is only $0.39 in favor of the USDA inspected facility alternative. However, some of the farmers in our survey indicated selling prices comparable to those of the off-farm USDA processed products.
The analysis of the economies of scale compares the profit from investing in a mini MPU (fixed cost $10,000) to the profit from investing in a traditional MPU (fixed cost $75,000). Results indicate with a capacity of under 1,500 processed birds per year, a traditional MPU incurs in a loss. However, with more than 8,000 processed birds per year, a traditional MPU is more profitable than a mini MPU.
The study also showed that the MPU is characterized by a significant excess processing capacity. A traditional MPU can process, on average, 45,000 birds per year. Sharing the ownership of the MPU and leasing it can produce additional revenue. For instance, if ten farmers who process 1,000 birds per year buy a MPU and lease it by charging a per bird fee of $3.50 to utilize the excess capacity can realize more profits than the off-farm USDA inspected facility processing option.
The analysis with respect to the financial cost indicated that a two years payback period requires 600 and 4,000 processed birds per year for a mini MPU and a traditional MPU, respectively. Furthermore, a 5% interest rate requires that a mini MPU processes 400 or more birds per year to avoid incurring a loss. In contrast, a traditional MPU can have positive profits with a 5% cost of capital equal by processing 3,000 or more birds per year.
The study indicated that the MPU has a good economic feasibility and it is a competitive alternative to the traditional on farm processing option. The incidence of the financial cost is high for a small number of processed birds per year, but for larger production levels and interest rates it can be a profitable option. Taking advantage of the excess processing capacity of the MPU can make this alternative more profitable than the off-farm USDA inspected facility option. This consideration is supported by an increasing demand for processing pasture poultry and by a relatively low supply for processing pasture poultry.
The economies of scale play an important role on the MPU profitability and they necessitate a careful analysis on the farmer’s side. A mini MPU requires a lower initial investment and for a small number of processed birds it allows a higher profit than a traditional MPU. However, a more consistent investment in the processing scale can provide more flexible solutions and generate higher profits for small farmers.
The research project benefits the pastured poultry producers by:
- Providing pastured poultry producers with data to improve the food safety of the pasture broiler carcasses by reducing Salmonella and Campylobacter contamination prevalence regardless of the processing method
- Informing pastured poultry producers that in term of food safety; there is no single processing method where chicken carcasses have Salmonella and/or Campylobacter positive contamination prevalence below 40% (considered high when compared to commercially processed chickens).
- Informing pastured poultry producers that process their chickens on-farm (on-site) that waste disposal is a potential source for pathogen dissemination to the environment (soil and compost).
- MPU has a good economic feasibility and it is a competitive alternative to the traditional on farm processing option.
Areas needing additional study
Further research is needed regarding the small-scale broiler production environment in relation to available processing methods, on-farm practices and pathogen level, the breed of bird, potential pathogen intervention methods, and disposal intervention methods.