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The Humane League UK v Secretary of State for Environment, Food and Rural Affairs and others

Updated: Jun 21, 2023

3 and 4 May 2023

URL: Citation: [2023] EWHC 1243 (Admin)

Advocates for Animals acted for The Humane League UK (THL), who brought a judicial review against the Secretary of State for Environment, Food & Rural Affairs (“the Secretary of State” or “Defra”) for the use of fast growing chickens bred for meat (broilers). National Farmers Union was an interested party in the case and The Royal Society for the Prevention of Cruelty to Animals (“RSPCA”) was an intervenor.

The Facts

The case centred around the use of broiler chickens that have been genetically selected to prioritise fast growth to produce the most meat in the shortest time possible. This growth rate causes health and welfare issues, which include: (i) heart attacks, (ii) lameness, (iii) green muscle disease, (iv) hock burns and (v) organ failure.

The RSPCA published a report in March 2020, which for the first time looked holistically at health and welfare issues attached to fast growth by comparing three fast growing breeds against a slower growing counterpart. Its executive summary states that the genetic selection of meat chickens for performance contributes to welfare problems such as chronic leg disorders, heart and circulatory problems. It also discusses the reduction in activities and behavioural patterns such as: “less active, spending less time walking and standing, and more time feeding and sitting, and spent less time engaged in enrichment type behaviours: foraging, perching and dust bathing.”

The trigger system assesses the results of inspections that are carried out by the Food Standards Agency (“FSA”) staff at slaughterhouses to determine if there are any welfare problems on a farm. The welfare conditions that are assessed are:


Cellulitis & Dermatitis

Dead on Arrival (DOA)


Joint lesions


Total rejections

Cumulative Daily Mortality Rate

A “trigger report” is produced if post- mortem conditions exceed a defined threshold in respect of chickens from the same flock. Annex 3 of The Code of Practice for the welfare of meat chickens summarises the thresholds as follows:

Process 1: A trigger report is generated if the level of a post-mortem condition is exceptionally high (defined as greater than 6 standard deviations above the average).

Process 2: A trigger report is generated if the Cumulative Daily Mortality Rate is unusually high (defined as greater than 3 standard deviations above the average = 7.37%) and, additionally, the level of three or more other post-mortem conditions is high (defined as above the average).

The trigger report is shared with the producer and the Animal and Plant Health Agency (“APHA”) which then identifies farms at highest risk on non-compliance.

The Law

The primary legal framework of this judicial review rests on: (i) Directive 98/58/EC or the “Farming Directive” and (ii) Directive 2007/43/EC or the “Chicken Directive” and the domestic transposed legislation.

The Farming Directive recognises the need for common minimum standards for the protection of animals that are kept for farming purposes. It ensures no animal must be kept unless it can reasonably be expected, on the basis of its genotype or phenotype, that it can be kept without ‘detrimental effect on its health or welfare’. The Chicken Directive sets down minimum rules for the protection of chickens kept for meat production. It also includes monitoring requirements to ensure that welfare detriment is detected and reported.

The above requirements are transposed into UK law through The Welfare of Farmed Animals (England) Regulations 2007 (WOFAR), which places a duty on people responsible for farmed animals to take all reasonable steps to ensure that the conditions under which the animal is bred or kept comply with Schedule 1. In addition a person responsible for conventionally reared meat chickens must comply with Part 2 of Schedule 5A

Schedule 1 includes a similar requirement to the Farming Directive Requirement, this being:

Paragraph 29

Animals may only be kept for farming purposes if it can reasonably be expected, on the basis of their genotype or phenotype, that they can be kept without any detrimental effect on their health or welfare.

Schedule 5A derives from the Chicken Directive and states:

Part 2, paragraph 15

(1) An official veterinarian conducting controls under Regulation (EU) 2017/625 in relation to chickens must evaluate the results of the post-mortem inspection to identify possible indications of poor welfare conditions in their holding or house of origin.

(2) If the mortality rate of the chickens or the results of the post-mortem inspection are consistent with poor animal welfare conditions, the official veterinarian must communicate the data to the keeper of those chickens and to the Secretary of State without delay.

The Claim

THL asserted that the defendant was in violation of paragraph 29 through the use of fast growing chickens, by virtue of the detriment experienced based on their genetic makeup. THL argued that the Secretary of State had misdirected herself as to the correct interpretation of paragraph 29, which had manifested in a range of unlawful practices and policies, including:

  1. A flawed Code of Practice, which did not offer any clarity on paragraph 29

  2. A flawed position that commercial productivity is a relevant consideration when complying with paragraph 29

  3. A failure to undertake any prosecutions for breaches of paragraph 29

THL put forward its interpretation of paragraph 29 as meaning if animals whose genotype or phenotype is such that, in modern farming conditions, detrimental effects on health and welfare arise, then they cannot be kept. THL claimed that the prohibition was a conditional permission and if this conditional permission was not satisfied, keeping of the animal would be prohibited. THL asked the Court to provide its interpretation of the provision.

The claimants also submitted that the Secretary of State had an unlawful monitoring enforcement mechanism termed “trigger system”. It was argued before the judge that the trigger System needed to factor in the paragraph 29 duty to detect any breaches of that provision. Further, it was argued that the trigger system had set the thresholds for detecting and reporting welfare issues unlawfully high as per the requirements under paragraph 15 Schedule 5A WOFAR and even if a report was triggered, it would not ordinarily lead to an APHA inspection.

THL also claimed that action being taken against non-compliant producers outside of the trigger system was remote. THL argued therefore that the system had an effect of concealing rather than revealing the true extent of the welfare problems.

A final argument was that the trigger system violates the principle of equal treatment as applied between compliant producers on the one-hand and non-compliant producers on the other. The operation of the trigger system treats compliant and non-compliant producers equally, but without justification. Non-compliant lower-welfare producers whose flocks suffer much higher levels of detriment are being treated identically, through non-enforcement, compared to higher welfare producers whose flocks exhibit much lower levels of welfare detriment and are more likely to be compliant. This is to the benefit of non-compliant producers who avoid regulatory costs without any material sanction, thereby skewing the market.

The Defence

The Secretary of State argued that she had no policy that condoned or permitted the use of fast growing chickens, despite fast- growing breeds being standard in the industry.

The Secretary of State acknowledged that there are higher welfare issues and risks with fast- growing breeds; however, it was argued that environmental conditions have a significant influence on the welfare for both fast and slow- growing breeds, such as: lower stocking densities and the use of straw bales or step platforms. As such it was reasoned that there is no scientifically agreed definition of what constitutes as detriment to welfare, and the risks of fast growth does not automatically result in “unacceptably poor welfare in all circumstances and therefore cannot (based on their genetics) be kept without detriment to their health and welfare.”

The Secretary of State argued that the trigger system was often cited as an example of “best practice” to monitor on- farm welfare issues and that the thresholds chosen were at appropriate levels to ensure proper reporting of poor welfare conditions. It was also claimed that there were other referral and complaints mechanisms.

The Secretary of State argued the unequal treatment ground was parasitic on the success of the other two grounds and as such it should fail.

The Judgment

A wealth of scientific evidence was presented to the Court along with the RSPCA report, this included a recent report by the European Food Safety Authority 2022, which concluded that fast growth causes welfare detriment.

The Court concluded that it was not its task to form a view on the scientific literature regarding fast-growing chickens [79], but that the task is to review what the Secretary of State has done and to decide whether it falls short in public law terms. The Court found that the Secretary of State assessed the literature and took advice from expert advisers, which led to her reaching the judgment that environmental conditions have some bearing on the health and welfare of fast-growing chickens. The Court found that the conclusion is not irrational, and it cannot be said to have left out material findings to which she should have given attention [78].

The Court was also asked to define the meaning of paragraph 29.

The Court found that the construction of paragraph 29 must take account of the potential criminal liability to which its breach can lead and as such required a narrower interpretation than what otherwise may obtain, as such it rules out that paragraph 29 constitutes a conditional permission if this means that keepers of animals are prohibited from keeping them subject to the condition that they can satisfy a criminal court (in practice, the magistrates' court) that as regards their genotype or phenotype they can be kept without detrimental effect on their health or welfare [88]. The Court felt that it was putting the burden too high to expect keepers to be familiar with scientific literature to prove this [ 91].

The Court ruled that paragraph 29 meant: given the breed of animal chosen for keeping for farming purposes, it must reasonably be expected by the reasonable person responsible for them that given their genotype or phenotype they can be kept in appropriate conditions without any obvious or deleterious effect on their health or welfare [94].The Court found that there was no support in the language or context of "kept for farming purposes" that meant kept in reasonably foreseeable farming conditions. Rather the Court found that paragraph 29 does not mean kept in any particular farming conditions and that it could mean kept in environmental conditions which improve the health and welfare outcomes of the animals from what might be the case if kept in other conditions. The Court concluded that the obligation under paragraph 29 is on the keeper who must keep the breed chosen in appropriate conditions without any detrimental effect on the animals' health or welfare [93].

Turning to the trigger system, the Court found that paragraph 15(2) of Schedule 5A does not quantify the thresholds to trigger reporting or further action and that the Secretary of State has also established other referral and complaints mechanisms for enforcement [106]. The Court concluded that as a matter of judgment the Secretary of State has chosen these thresholds as the appropriate levels to ensure reporting of poor welfare conditions and that the criticisms do not meet the high threshold for a successful irrationality challenge, especially in this type of technical area where experts can differ [107].

Finally, on the principle of equal treatment, consistency of treatment is regarded as rational behaviour, so that inconsistent treatment is only reviewable if it is deemed irrational. The Court stated that even if it could be shown that the trigger system leads to failures of enforcement, that of itself would not amount to inconsistent treatment and even if inconsistent treatment was established then you would need to show such treatment was irrational. The Court concluded this had not been evidenced [109].


The fate of billions of animals was hanging in the balance. Despite evidence that fast-growing chickens suffer from lameness, heart attacks, organ failure and burns to the skin, the Court ruled in favour of the government on technical grounds. It is THL’s view that the law clearly applies to the detriment suffered in standard conditions, of which the science proving this happens is plentiful, but in any event adjusting the birds’ environment is not enough to improve their welfare since the complications arise from their genes itself.

Whilst the trigger system may have been deemed proportionate by the Court, the issues connected to it still continue. The high thresholds mean unlawful producers go undetected and issues go unaddressed.

The judgment essentially shifts the onus on the farmers, requiring them to find the environment where the breeds can be kept without detriment. This is a significant burden when the legislation and guidance is geared towards the standard conditions.

An appeal has been launched against the High Court’s decision.

Advocates for Animals instructed Brendan McGurk and Ed Brown KC.

Getting advice

This post is not legal advice and should not be relied on as such. If you require legal advice on animal protection laws please contact

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