An Approach to Building a Sustainable Small Flock Poultry Operation Through Improvement in Nutrition, Food safety, and Marketing

1. Establish specific dietary energy level that is optimal to calcium absorption for an egg type  breed in a free-range pastured operation

Treatment diets and husbandry practices

A commonly reared egg- type breed, Rhode Island Red, will be utilized in the study. Day-old chicks will be obtained from a reputable hatchery and will be raised with common starter and pullet diet (0-19 wks.) until the production phase at the TSU research farm utilizing a free-range pastured poultry system (Cheatham County). Experimental diets (corn-soy based) will consist of three different energy levels (~135 kcal/lb difference). This experiment will also test organic soy-free diet. The dietary energy level of soy-free diet will be selected based on field practice that will be determined after Workshop 1 of this project. The major ingredient for soy-free diet will be corn and other minor ingredient will include wheat. Calcium levels and other nutrient profile of test diets will be kept constant (Table 1). All the ingredients used in test diets: corn, soy, and wheat, are the major crops grown in TN.

Table 1. An illustration of nutrient profile of experimental diets.

*The energy level chosen for treatment 1 is the recommended energy levels for a typical commercial egg-type breed. TBD: To Be Determined. TRT= Treatment. TRT 1-3: conventional corn-soy diet; TRT 4: Organic soy-free diet.

There will be three replicate plots per treatment, with 20 birds per replicate at production phase (~ 200 sq. foot run/replicate). Pasture will be rotated every 7 days. Forage coverage % will be accounted for each rotation made. Regression approach will be utilized to understand the dietary energy required for optimal calcium absorption (TRT 1-3). There will be a total of 12-week experimental period from week 20 to 32 wks. of bird age.

Performance and egg quality parameters

Following performance data (TRT 1-4) will be collected during the study period: 

• Body Weights: 0, 2, 4, 6, 8, 10, and 12 weeks post start of the experimental period
• Feed: Feed consumption; Conversion (g egg/g feed), feed costs
• Egg production and egg quality parameters: Daily egg output/treatment, Egg quality (shell mineral analysis, shell thickness, and specific gravity) at three occasions during the 12-week experimental period spaced out evenly
• USDA egg grade evaluation and cost-benefit analysis based on the current feed and egg prices for each treatment
• Mortality %

Physiological parameters

Two birds per replicate will be sacrificed to collect blood and tissue samples (Treatment 1-3). Calcium (Ca) levels in blood, and Ca digestibility (ileal) will be measured at three different occasions (4 -week interval) during experimental period. Titanium dioxide will be used in feed as indigestible marker and digestibility values will be measured as discussed in Maharjan et al., 2019.. The circadian dynamics of Ca- metabolism related hormones in blood (dihydroxy cholecalciferol (1,25 (OH)₂D₃), 17β-Estradiol-2, Parathyroid Hormone (PTH), calcitonin, and Parathyroid Hormone-Related Peptide (PTHrP)) and eggshell calcification related genes (calbindin d28k, clusterin, carbonic anhydrase II (CA2), ovalbumin (OVA), ovotransferrin (OVO), ovocleidin-17 (OC-17)) for differential expression in the duodenum, kidney, and uterine tissue in the 24-hour egg laying cycle will be measured (Ma et al., 2020).

Statistical analysis

Performance data (body weight, feed efficiency, egg production, and shell quality) will be considered as response variables for treatment diets (TRT 1-4). Each replicate patch will be considered as experimental unit for performance data analysis. For physiological data, pooled values of multiple (two) hens sampled from each replicate will act as an experimental unit for response variables measured (hormones, differential gene expressions, Ca levels in blood and tissue, etc.). Within treatment, data will be checked for outliers. Outliers are not automatically rejected but only after check of plausibility. The data obtained for variables measured will be analyzed by one-way ANOVA using JMPro 15(SAS Institute, Inc., Cary, NC). Significant means will be separated at P<0.05 using Student’s t- test or Tukey’s HSD where appropriate. Individual regression lines will be drawn to understand the dietary energy required for optimal calcium absorption, eggshell quality, and performance parameters.

Educational material output:

• Bird responses to dietary energy levels on performance
• Specific dietary energy level that is optimal to calcium absorption

2. Evaluate performance and egg quality differences for conventional and organic soy-free diets between farms

 The on-farm rearing of the birds will be performed by the three co-operating farmers (Susan Kyle, Ron Bridges, and Cynthia Capers) in their respective farms, with either conventional or organic based diets (Table 3). At least 50 birds will be utilized at each farm, and study will be conducted for the 12-week period at the same time as TSU research farm utilizing the same batch of birds. Treated and untreated drinking water supplies will be alternated weekly for these farms with co-operating farmers and at TSU research farm for Treatment 4 diet. Environmental friendly UV-based water treatment technology will be applied to  sanitize farm water supplies. Feed conversion values, daily egg production, egg weight, eggshell quality, and livability will calculated for conventional and organic based dietary approaches for each farm (of co-operating farmers) and will be compared with performance values obtained at TSU research farm. The fatty acids profile of eggs will also be measured between these two feeding approaches. The co-operating farmers have been informed  about their roles (research and education components) in the project. Furthermore, they have actively participated in planning of project and the farm trial. We have had opportunity to meet in-person through on-site farm visits (Rustic Farm and Heniscity Farm) and remotely via (multiple) zoom meetings.

Table 3: Dietary table for on-farm studies by co-operating farmers

Educational Output:

• Possible farm to farm variation in performance outputs for same dietary approaches
• Impacts of poultry water supplies treatment on performance (within farm comparison).

3. Assessing prevalence of Salmonella species, E. coli O157:H7 and Listeria monocytogenes under treated and untreated water supplies

Three farms under co-operating farmers and the TSU research farm (Treatment 4 replicates) will be subjected for this evaluation. During the 12-week experimental period, poultry drinking water samples, egg rinse samples and cloacal swab samples will be taken biweekly and assessed for the prevalence of foodborne pathogens (Salmonella spp., E. coli and Listeria). There will be total of six sampling occasions- three occasions will be utilized on the 7^th day during when water treatment is in place, whereas other three occasions will be during when water supplies are not treated.   Eggs (n= 15), and cloacal swabs (n=10 birds) and water supply source will be aseptically collected from each farm on each occasion. All samples will be transported in an insulated foam box with ice and processed in the laboratory within 24 h of collection or stored overnight at 4°C until processed the next day.

Procedure for microbial analysis

Each egg will be placed separately in a sterile bag containing 300 mL of buffered peptone water (BPW) and manually rinsed for 2 min, ensuring that all external parts have contact with the rinse. Sterile cotton swabs in 0.1% BPW will be used to take cloacal samples and thereafter will be immersed in 10 ml of 0.1% BPW and vortexed for 30 s. Farm drinking water (10 ml) and 90 mL of BPW will be added and pummeled in a stomacher 400 circulator at 230 rpm for 2 min. All homogenates will be evaluated for Salmonella spp, E. coli O157:H7, Listeria monocytogenes by using both traditional and biochemical methods.

Detection of Salmonella spp, E. coli O157:H7 and Listeria monocytogenes characterized according to (Liu and Kilonzo-Nthenge, 2017). Briefly, 0.1 ml of each pre-enriched sample will be added to 10 mL of Rappaport-Vassiliadis (RV), enterohemorrhagic E. coli enrichment broth, and Listeria enrichment broth base, respectively, and then incubated at 37°C for 24 h. Similarly, for each water sample, 1 ml will be added directly to 10 ml of each respective broth and incubated at 37°C for 24 h. Consequently, a loop (10 μl) of cultured broths will be streaked onto respective plates: Xylose-Lysine-Desoxycholate (XLD) selective agar (Oxoid, Basingstoke, Hants, England) for Salmonella spp, Sorbitol MacConkey agar (CM0813; Oxoid) supplemented with cefixime (50 ng/ ml) and potassium tellurite (25 mg/ml) supplement (SR0172E; Oxoid) for Escherichia coli O157:H7, and Listeria selective agar for Listeria monocytogenes. Plates will be incubated at 37°C for 24 to 48 h. Presumptive Salmonella spp colonies of red, yellow with black centers, colorless E. coli O157:H7, and brownish-black colonies Listeria monocytogenes presumptive colonies will be preserved in sterilized 80% glycerol at -80 ºC for confirmation with PCR.

Educational outputs:

• Understand the relationship of food pathogen prevalence that exist between environment (treated versus untreated water supplies), bird (cloaca) and farm produce (eggs)

4. Assess cost associated with production inputs and performance outputs in each conventional and organic based dietary approaches by preparing budget sheet and evaluate profitability (Dr. Lawani and co-operating farmers)

During the experimental phase, data will be collected to estimate production and marketing costs in each conventional and organic based dietary approaches for small flock production. The data will be used to generate sample budgets for each approach and analyzed to compare their profitability.

The budget will consider three time-horizons: raising of rearing phase (before egg production), production phase, and the marketing phase. In addition to the cost commonly associated with rearing chickens, some specific costs will vary and will be related to each time horizon. During the rearing phase, we will collect variable costs associated with the pullet diet. In the production phase, the cost of the experimental diets with the associated three different energy levels will also be evaluated in addition to the cost related to feed consumption and other operating costs. During the marketing phase, we will examine different scenarios. We assume that most of the production will be sold directly to consumers through farmers markets, roadside stands, or directly on the farm. We will also examine indirect marketing options where producers can sell for example as a group to retailers. The rationale behind separating the time horizon into three phases is that i) it allows us to identify the source of difference of performance between the conventional and organic based dietary approaches for small flock production, ii) it offers farmers the possibility to change/adapt their strategy to the market conditions (e.g., if after the day-old chicks raising farmers realize that the market price will not lead to a profitable enterprise, they can change and use the conventional approach instead of the organic based dietary one).

We will also conduct research on consumers’ willingness to pay for organic based dietary eggs. This research will help us estimate how much more consumers are willing to pay for eggs produced using this approach and their market share. We will use a choice experiment for this research. A choice experiment is a tool to elicit consumer utility and is widely applied in consumer studies. Choice experiment allows researchers to uncover how consumer value attributes of a product by asking them to state their choice over different alternatives. The stated choices are econometrically estimated and transformed into utility.  This research will be conducted using a representative sample of U.S. consumers through Qualtrics.

The results will be published in extension outlets. Sample budgets will also be developed in Excel and made accessible to farmers. Farmers will also be trained on using the budgets and the marketing strategies for profitable small flock poultry operation.

Education outputs:

• Hands-on on budget sheets, and product pricing, and marketing options 

PS: The flow diagram for bird trial and activities involved are outlined herewith. Farm trial_ outline

LOS_ Research Dean_SSARE Research and Education

5. Educate small flock producers, county agents, and poultry stakeholders on basics of feeding, food safety practices, and farm economics for sustainable poultry operation 

Detailed out in the Outreach Plan.