Chicken Shit 
Cachu Iar

Phosphate + Protein Methodology

This report is produced from a file of predominantly visual evidence of the metabolic violence along Cargill’s supply webs, from soy to supermarket. We will travel along one specific strand of the web, viewing images and other forms of evidence that are specific to either the locations along the supply web, or the species that inhabit it. For example, images of the Water Crowfoot used were captured on the Wye, while a PhD thesis included here discusses the impact of phosphate on the same species that lives on the Wye.

We will zoom into the moments of metabolic violence, to understand how the flow of protein and phosphate causes harm to the bodies of the chickens and Water Crowfoot. At other times we zoom out, to map the flow of protein and phosphate across the landscape of the River Wye, and the logistical network that funnels feed from Brazil to Herefordshire. Further methods for zooming in and zooming out are detailed in the Investigative Mapping document.

Evidence was gathered remotely through desktop research, from Google searches, to planning portals, to industry literature, and mapping databases. These are images of spaces changed through the flow of phosphate and protein, in different scales and concentrations. Where possible, the images have been geolocated – cross-referencing maps and aerial views with visual clues in the images – to situate them accurately in space. Metadata is displayed next to each image, detailing the date and location of capture and the tool used. Images are constructed and their meaning and evidentiary capacity changes in the process of making. One example is a long focal length can make objects seem closer in the image than they would be in plan. Another is false colour, the staining of microscope slides, or the combination of satellite image colour bands – both produce an image that can be read and analysed with a key but does not represent the colours seen with a naked eye.


The increase in chicken farms in the Wye catchment correlates with an agreement signed by Cargill in 2013, to increase the supply of poultry produce to Tesco, exclusively from their Hereford processing (slaughter) centre. In 2018, Cargill’s UK operations merged with Faccenda Foods, becoming Avara Foods, further consolidating the industry. Avara in 2019 extended their processing centre after a further increase in demand from Tesco and recruited more chicken farmers for supply. Campaigners have recently called for Tesco to ‘clean up’ its supply chain and prevent phosphate from entering the River Wye (Laville 2022). In response, Tesco issued standard assurances that is has been working with stakeholders and does indeed care about nature.

Campaigners have been arguing that the intensive chicken industry pollutes the Wye directly. However, a combination of incomplete regulatory data, farming guidelines, and subcontracted supply chain enable Tesco and Avara to distance themselves from the consequences of the production they demand. Chicken farmers are contracted to Avara, and Avara supply Tesco. For the purposes of this report, Avara is referred to as Cargill. Cargill controls the supply of feed that is used by Avara’s farmers, and therefore naming them as Cargill highlights the continuity of their control.

We start in the Wye, tracking the disappearance of the water crowfoot plant, a keystone species for the habitat, as it is subsumed by algae. We depart from the Wye by following the trail of phosphate, travelling through the fields, the spreading of shit, back to a farm known to be contracted to Cargill, Penrhos poultry. This farm has been unusually open in allowing press inside and has won industry awards for its farming practice. We use this example to critique the best practice of the industry.

From Penrhos, we track the feed back to soy production in Brazil, to a farm accused of deforestation. We use this example to highlight different types of violence in this region, how it is linked to phosphate, and debate the temporal framing of what the industry defines as deforestation-linked soy. After this, we follow the trail of protein processing back to Penrhos. Here, we zoom into the body and metabolic violence enacted on the chicken. Rather than accusing Penrhos directly and singularly of this violence, we have found evidence in the manuals and documents of the chicken breeding company Aviagen, of widespread suffering across the industry.

Form and Function

This report taps into the legacy of travel guides and the River Wye. In 1782, Gilpin published his guide ‘Observations on the River Wye’, kickstarting tourism in the area and the picturesque art movement. His book contains images on and by the river, alongside comments on their portrayal. Unlike the picturesque lens, which saw nature as separate and passive, we follow its entanglements with the supply web. The format of this booklet, and the map that accompanies it, references the Ordnance Survey Explorer maps that will be familiar to hillwalkers in the catchment following the Wye Valley Walk. The documents rely on each other, the booklet zooms in at points on the map. The footnotes on each page point to the stage of the supply web it occupies and details the path behind and ahead.

The publication is aimed at tying together the separate critiques of the intensive chicken industry, from animal rights and conservation perspectives. It is rooted in a more critical stance against the capitalist mode of agriculture than most organisations and campaigns around the Wye. Throughout the report, snippets of theory that have informed this critique are included. As you read this report, please take note of the links between the evidence, theory, and comment, as with the metadata, image locations, and mapping.

Above all, this is a friendly intervention in the spaces of activism. It is an invitation to consider evidence, reporting, mapping, and critique in other forms and angles, and an invitation to collaborate. At the end of the report, I pose questions on policy and areas for further investigation that were outside the scope of time and energy put into this work. Questions shift the emphasis for improvement on the companies and regulators more than recommendations do (Dudai 2006), while demands should be collective, situated, and are not for this report to dictate.

The word shit is used here because it is more evocative of the potency of the pollution, manure implies productivity, it does not cover the full stink of the situation (Caffyn 2020).

Let’s stir some shit.

Mapping Methodology

Factory Model

While the chicken industry emphasizes the biosecurity and control that their sheds provide, what really matters in the flow of protein and phosphate across the catchment is the intensity of production inside. In planning applications, however, the plans and sections are blank inside – detailing only the structure of the sheds. This shed was reconstructed from an image of Penrhos Poultry, known to be an example of ‘best practice’ in the industry (National Egg and Poultry Awards 2020). An imagewas placed in the modelling software Blender, after the image capture
height was estimated. Through iteration, a structural bay of the shed was reconstructed, using particularly the locations of feeders, ventilation, pipes, and windows, added to a floor template taken from measurements of scaled aerial imagery. The brands of the feeders and water drippers were identified from the logos and shapes in photographs and reconstructed from the manufacturer’s installation manuals. This bay has been multiplied to the length of one (of four) sheds at Penrhos.

The floor area per chicken was calculated from the stocking density (Wasley and Davies 2017), and the dimensions of the whole shed. The sizes of the chicken were estimated in comparison to the size of the feeders from images of Haywood Poultry (Viva! 2021). This farm uses the same brands of feeders and chickens as Penrhos. The images show birds that have just arrived at the shed as chicks, and chickens that are just days away from slaughter.

Shit Map

The locations of the chicken farms are sourced from a dataset compiled by Caffyn and Hugh-Jones, who trawled Herefordshire, Shropshire, and Powys planning portals (Brecon and Radnor CPRW and Herefordshire CPRE 2021). This map shows only the broiler (meat) factories, while their data includes hatcheries, egg production, and turkey farms. The red ring indicates the likely catchment of Cargill’s processing centre. Farm within this area face minimal regulation in the transport of chickens and are more likely to supply Cargill (DEFRA and APHA 2022). There is no publicly available data to confirm which farms supply Cargill, outside of news reports, animal rights investigations and anecdotal evidence.

Studies estimate that the economy of transporting dry manure, chicken litter, is limited to 50 km (Scarlat et al. 2018), while a major phosphate report confirms that shit rarely escapes the catchment (Withers et al. 2022). For each farm a shaded ring of 50km in radius was added to estimate the maximum area the shit could reach. This is overlaid with a crop map from the UK Centre for Ecology and Hydrology, which shows all of the arable farms that the shit could be spread on. The more opaque the field is, the more likely that shit will be spread. The paths of the Wye and Lugg and their catchments are sourced from Friends of the Upper Wye (Brecon and Radnor CPRW and Herefordshire CPRE 2021).

Financial Map

Campaigners cite the defunding of the Environment Agency as allowing the algae blooms to occur (Monbiot 2022), with a lack of staff to test and enforce water quality. This timechart maps the annual funding and spending of the Environment Agency and its Welsh counterpart. It is not clear from the annual statements exactly where their budgets have been cut. Available in 2009, 2010 and 2021 is the budget for national river-specific spending, which has reduced significantly. Underneath this are the annual revenues of three major actors in the poultry and egg industry in the Wye catchment. The annual, national revenues are sourced from statements filed to Companies House.

Algae Map

This timechart tracks the disappearance of the Water Crowfoot, a keystone species of the Wye, and reports of algae blooms. Evidence of algae are sourced from Twitter through searches of “Wye” in combination with “algae”, “bloom”, “green”, “brown”, “stink”, and “slime”. Similarly for the plant, “Wye” and “Ranunculus” or “Water Crowfoot”. Tweets were logged that mentioned a specific location, a specific time, or both. For those that had no specific time, the date of posting was used.

This chart is a template to build on, an invitation for collaboration. It uses situated, testimonial evidence as its basis to challenge the privileging of data by the Environment Agency: local people are convinced that the Wye is deteriorating, even if Natural Resources Wales denies this (McEwan 2022). This chart could be overlaid with data gathered from the significant citizen science efforts in the catchment, and reports from other sources – from news articles to online fishing forums, to a physical installation as evidence gathering.

Soy Sensing

Cargill had been accused of breaking an industry moratorium, after purchasing soy from a farm that had deforested the area the soy was grown on, within the timeframe that the moratorium stipulates (Wasley 2022). Fazenda Conquista, the farm, disputed this and provided a screenshot from Google Earth as evidence that clearing had taken place legally, on ‘consolidated’ land (Repórter Brasil 2022). The official body that investigated and found the farm to be at fault supplied only a partial and grainy image. This was an exercise to confirm the allegations and
understand where and when the deforestation took place in relation to the images of soy plantation (Wasley 2022).

Scrolling through the historic satellite imagery in Google Earth reveals that, aside from the years 1985 and 2021, the tiles of satellite imagery fall outside of the boundaries of the farm. This creates a problem for Fazenda Conquista’s assertion that images are more reliable than words (Repórter  Brasil 2022).

The second step was sourcing satellite imagery from the U.S.G.S, spanning from 1985 to 2021, across three different satellites – Landsat-5, Landsat-7, and Landsat-8. Images from these satellites are available in different bands, capturing different wavelengths of light. Combination of bands are chosen, and images layered (in this case in QGIS) to emphasise and highlight different qualities. Here, the shortwave infrared combination displays vegetation density. One image is striped, a combination of photographs from 2010 – 2012 to compensate for missing data in these years. More detail on this phenomenon can be found here: (Schuppli 2013).

Clear deforestation is visible in 2013, encroaching on the ‘unconsolidated areas’ pinpointed in Fazenda Conquista’s map. Geolocating a drone image captured by journalists of Conquista’s soy plantation, the coordinates found in the metadata of the image, confirms that the northern ‘unconsolidated’ zone was cleared and planted with soy, triggering the violation of the moratorium.


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