How do farmers manage animal health?

Animal health is managed by the farmer in partnership with a veterinarian and other agricultural advisers. It begins with the animal selection where the farmer looks for traits such as longevity of animals, robustness, resource efficiency, and environmental impact. And it continues with an animal health management plan which includes concepts such as: biosecurity measures, good housing, good hygiene, appropriate nutrition, regular monitoring of health and welfare including vaccination when advised, and treatment of illness when necessary.

Animals, just like people, can get sick, no matter the farming practices, and they require proper care from the veterinarian and the farmer. Reducing infections in animals is also important for improving food safety, food yields and reducing any animal suffering. Good husbandry, biosecurity and hygiene are the cornerstones of protecting animal health and welfare on Europe’s farms.

The use of vaccination to prevent disease along with good farm hygiene, herd health plans, and good nutrition are the first steps in reducing the occurrence of bacterial disease. Whenever possible, farmers adhere to the concept that prevention is always better than cure. Use of diagnostics and other innovative technologies like digital monitoring can also assist with earlier disease detection help support a more targeted health management.

Despite best efforts however, like people, animals can get sick. It is the farmer’s duty to provide appropriate care as advised by a veterinary surgeon in case of illness.

What is genetic improvement of animals and why is it important?

Those with a more vivid imagination may envisage genetic improvements to mean creating giant chickens and enormous cows, but this is science-fiction! Breeding and selection of best traits of animals are important for animal resilience and is often focused on selection of best traits and improvements to health, disease resistance, feed efficiency, etc.

Animal breeding plays a crucial role in the European food supply chain, balancing efficiency, availability and minimal environmental load. Farm animal breeding aims to support more sustainable livestock production by selecting for traits such as longevity of animals, robustness, efficiency, environmental impact, animal health, and animal welfare while addressing the key issues of food safety and public health, product quality and preserving genetic diversity, etc.

As an example, the genetic improvement of pigs, poultry and fish over the past 30 years has (together with animal nutrition science) allowed for a significant improvement of the feed conversion ratio, without affecting animal welfare. Farm animals have effectively become more efficient in the conversion of feed into animal product, meaning farmers have needed to use less feed for their herd to obtain the same, or even better results. This means a financial gain for the farmer, but it also has an environmental advantage due to less manure production and therefore less nitrogen excretion.

Less need for feed is considered as an efficient use of resources, a criteria that forms an integral part of sustainability. As our increasingly globalised market requires breeders to supply everywhere for any kind of farming, more efficient animal breeding stock will help to meet the growing demand for all livestock products. Responsible breeders aim to meet to this demand in as balanced a way as possible, selecting animals that can produce in an economically viable way whilst taking care of the animals and making efficient use of feed and other resources that are required for good husbandry.

- Code of Good Practice for Farm Animal Breeding and Reproduction Organisation

Chickens in intensive systems grow fatter faster! - is this true?

Birds naturally grow fast. Through breeding selection, chickens and domestic ducks have increased this “fast growing” process.

Modern breeding techniques have managed to optimise the bird growth, feed intake alongside good animal health and welfare. Contrary to what some people think and to what is sometimes reported, the birds do not have weakened legs that break easily or are unable to support their own weight. The idea that birds cannot move, cannot drink nor eat is also false as this would be bad not only for the bird but for the farmer’s investment. No farmer wants to lose animals!

Breeders provide the best genetic improvements they can so that farmers can produce healthy chickens. In fact rearing healthy, thriving birds is the aim of European poultry producers in adherence to European animal health and welfare standards, while supporting sustainable and responsible production techniques. Growth challenges may arise due to nutritional deficiencies, but this can be resolved through improved nutrition.

An EU directive from 2007 also lays down minimum rules for the protection of chickens kept for meat production.  It aims to reduce the overcrowding of chicken holdings by setting a maximum stocking density and ensure better animal welfare by specifying requirements such as lighting, litter, feeding, and ventilation.   

- Council Directive 2007/43/CE (June 2007) 

Why do farmers use antibiotics ? Do alternatives exists?

Just like when people get sick, farmers sometimes need to use antibiotics when their animals fall ill with a bacterial infection. In Europe antibiotics are only prescribed for livestock following diagnosis by a veterinarian and there are strict rules as to when and how they can be used.

Managing the health of animals on farms may require the use of veterinary medicines, including antibiotics. No matter the type of farming practices used, like people, on occasion animals can get sick and farmers have a moral and legal obligation to keep their animals healthy and ensure they receive appropriate treatment. This is why farmers sometimes need to administer antibiotics.

Antibiotics can only be used by farmers to treat sick animals at the direction of a veterinarian. Antibiotics are prescription-only medicines in Europe and are therefore only available for use by farmers following diagnosis by a veterinarian and after provision of a veterinary prescription. 

The veterinarian can prescribe antibiotics to control disease in a group of animals where one or more animals are already sick, to prevent the spread of an infection where no appropriate alternatives are available. The veterinarian can also prescribe antibiotics for an individual animal or a restricted number of animals to prevent infections when the risk is high, for instance following certain surgical procedures Antibiotics cannot be used routinely nor to compensate for poor hygiene, inadequate husbandry or poor farm management. In Europe farmers have signed up to the Responsible Use principles as set out by the European Platform for the Responsible Use of Medicines in Animals(EPRUMA) under the best-practice framework for the use of antibiotics in food-producing animals. EPRUMA sets out guidance on how to stimulate optimal animal health as part of a farm management plan, which aims at reducing the need for antibiotics. 

This is based on a holistic approach of minimising disease through infection prevention approaches including:

  • Biosecurity: a set of preventative measures aiming to keep groups of animals healthy or to limit the spread of diseases within an animal population
  • Good housing and ventilation
  • Good hygiene
  • Appropriate nutrition
  • Regular monitoring of health and welfare
  • Animal health planning
  • Use of diagnostics
  • Vaccination
  • Reporting any adverse events to the pharmacovigilance system

Aren’t there alternatives to using antibiotics?

When an animal is hit by a bacterial disease, there is no alternative to antibiotic treatment for that animal. But some infection prevention actions and productsexist which help to reduce the needfor antibiotics; these can be broken into two main categories: 

  • Preventive: biosecurity, good housing and ventilation and also the use of vaccines that protect animals from specific diseases
  • Supportive: those products which help to maintain the animal in good health, for example optimal nutrition and probiotics

Whilst there are currently no therapeutic alternatives to antibiotics authorised for use in livestock in Europe, there are however a number of susceptibility enhancing productse.g. virulence modifier. 

Nutrition, can play a very important and even critical function in the maintenance of optimal animal health and welfare. Feed additives used in feed for farm animals are pivotal contributors to ensuring adequate nutrition and optimal animal welfare. Such ingredients not only ensure the safety of feed (e.g. reducing the presence of undesirable microorganisms), but they can also improve digestibility and maintain the balance of the animal’s gut flora, supporting their welfare, resistance and resilience to eventual infections or stressors.

Are antibiotic growth promoters used in animal feed?

No, using antibiotics for growth promotion purposes was banned in 2006 under the EU Feed Additives Regulation – Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 September 2003 on additives for use in animal nutrition as a measure to tackle antibiotic resistance.

The fact that the use of antibiotics as growth promoters has been banned in Europe remains widely unknown amongst the general public. This was recently demonstrated in the latest European barometer 522 on Antimicrobial Resistance (2022) which showed that only 42% of EU citizens know that using antibiotics to stimulate growth in farm animals is banned within the EU.  

Since the 2006 EU ban on the use of antibiotics as growth promoters, other continents have decided to follow this example underpinning the position of the EU as a best practice region as outlined in the EU One Health Action Plan on Antimicrobial Resistance.

- Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 September 2003 on additives for use in animal nutrition 

Does feed include ingredients derived from genetically modified crops?

Indeed livestock animals get a diet that can contain feed ingredients produced from genetically modified (GM) crops. It is well known for example that a very large proportion of soybean meal used in the EU is produced from genetically modified soybeans.

All feed materials produced from GM crops that are used in the EU have been tested for food and feed safety by the European Food Safety Authority. A large body of scientific research supports the view that authorised GM crops are as safe for human or animal consumption as their non-GM equivalent. In addition, GMO-derived feed materials have been included in animal feed manufacturing for more than 25 years. The current application of GMO technology in crops focuses on increasing beneficial traits to arable farmers, such as increased yields and reduced pesticide use, meaning currently available feed materials derived from GMO crops do not provide any particular nutritional advantage or disadvantage to European livestock farming.

With the large penetration level of GMO technology in large agricultural exporting countries (e.g. USA, Brazil, Argentina), GMO-derived feed materials have simply become mainstream in global commodity trade, particularly for soybean and maize. Considering that the EU is still dependent on the global market for its supply in feed, in particular high protein-rich feed materials (30-50% of protein content), EU operators must import feed materials derived from GMO crops.

Feed delivered to livestock farmers containing more than 0.9% GMO-feed materials is labelled accordingly. In different Member States a number of initiatives have been developed to cater to the demand for animal products fed with ‘non-GM feed’. Therefore choice is offered to consumers who wish to purchase these kind of animal products.

- Regulation (EC) 1829/2003 of the European Parliament and of the Council on genetically modified food and feed was adopted on 22 September 2003

Animals consume 70% of all antibiotics in Europe! - is this true?

Whilst this number is technically correct, what does it actually mean? It’s a great shock figure that is often quoted, but the gross tonnage that is used to get this figure is a poor way to compare the use of antibiotics in humans and animals. The population biomass-corrected calculation indicates a lower consumption of antibiotics in livestock than in people in 18 EU countries.

Gross Tonnage as a measurement does not take into account two very important factors:

  • The Potency of the Antibiotic:most of the newer antibiotics commonly used in human medicine are more potent and thus require the use of a lower dose than the older antibiotics commonly used in veterinary medicine. In other words, one ‘therapeutic dose’ of the newer antibiotics commonly used in human medicine weighs less than the equivalent ‘therapeutic dose’ of the older antibiotics commonly used in veterinary medicine. That is why a better comparative figure is the number of therapeutic doses used in each sector.
  • Biomass: the dose of an antibiotic is calculated on the bodyweight of the patient, a 650 kg Dairy Cow would therefore need a much larger dose than a 80kg person. Animal numbers also play their part. For instance chickens, although weighing much less, are far more numerous with billions of chickens being produced for consumption in the EU every year. Because of this, milligrams of antibiotic per kilogram of bodyweight (mg/kg bodyweight) is a better measurement of the tonnage used.

According to a recent EU reportstates “ In 18 of 28 countries, the population biomass-corrected consumption was lower or much lower in food-producing animals than in humans, in two countries, the consumption was similar in both groups and in the eight remaining countries, the consumption was higher or much higher in food-producing animals than in humans.

ECDC/EFSA/EMA second joint report on the integrated analysis of the consumption of antimicrobial agents and occurrence of antimicrobial resistance in bacteria from humans and food-producing animals

Is there a risk of medicine or antibiotic residues in the food we eat?

No, there are no harmful residues of antibiotics in the food we eat. Strict EU rules protect the consumer from any harmful residues in animal-sourced foods by setting a timeframe for antibiotics or other medicines to be eliminated from the animal before any food products enter the food chain.

Protecting the consumer

By law foodstuffs, such as meat, milk or eggs, obtained from animals treated with veterinary medicines or exposed to biocidal products used in farming must not contain any residue that might represent a hazard to the health of the consumer. EU rules set the standards for “withdrawal periods”. This is the minimum time lapse required between the treatment of an animal and when it or its produce is allowed to enter the food chain. These are established for each veterinary medicine to ensure that if residues arise from treating animals, they are at levels below specific, scientifically set limits (maximum residue limit). The amount of a veterinary medicine present in treated animals and their products, such as milk or eggs, declines over time as it is metabolised and is eliminated from the animal’s body. Tests to establish the rate at which these levels decline are part of the food-safety testing that must be submitted by companies requesting permission to sell a new veterinary medicine for use in food-producing animals.

This assures that no unsafe residues are found in food. As a precaution the actual maximum residue limits are often thousands of times lower than the level at which any traces of a medicine would have any impact on consumer health. 

These limits are strictly monitored by national authorities to ensure, through residues surveillance schemes, that all foods coming from animal products are safe.

EU Regulations on residues 

All animal medicines are strictly regulated, meaning that their quality, safety - to animals as well as people and the environment - and efficacy is assured. In addition, there are a range of safety factors in place to protect consumers. Where animals have been treated with medicines, regulatory bodies such as the European Medicines Agency and CODEX (a standardisation body supported by the FAO and WHO) set strict limits on the residual levels permitted to enter the food chain. All veterinary medicines including antibiotics used in farm animals have maximum residue limits (MRLs) set under MRLs Regulation 470/2009and listed in Regulation 37/2010. The assessment of the safety of residues is carried out by the EMA’s Committee for Medicinal Products for Veterinary Use (CVMP). Establishing maximum residue limits involves several steps. At each stage, regulators build in a safety factor designed to minimise any potential risk to those consuming food from treated animals. 

The latest reportfrom the European Food Safety Authority (2017) on the results from the monitoring of veterinary medicinal product residues show that for overall residues, 99.69% of samples provided were compliant. And for antibacterials, which includes antibiotics, 99.83% were compliant. The samples are analysed according to specific EU rules: Council Directive 96/23/EC on measures to monitor certain substances and residues thereof in live animals and animal products.


In organic farming, animals do not receive medicines or vaccines! - how accurate is this?

No matter the type of farming practice, animals can get sick and farmers have a moral obligation to keep their animals healthy, so yes, animals on organic farms may receive medicines at some point in their lives if they are ill, or vaccines to prevent a disease.

In the case of both organic and conventional farming systems animals can be prescribed antibiotics to treat bacterial infections. The EU Regulation[ref]Regulation (EU) 2018/848[/ref] on organic production and labelling of organic products stipulates that: 

  • When the animals are ill, allopathic veterinary medicinal products including antibiotics may be used where necessary and under strict conditions. This is only allowed when the use of phytotherapeutic, homeopathic and other products is inappropriate 
  • The use of immunological veterinary medicines is permitted, i.e. vaccines. Where an animal or a group of animals receives more than three courses of treatments with chemically synthesised allopathic veterinary medicinal products, including antibiotics (excepting vaccinations, treatments for parasites and compulsory eradication schemes), within 12 months, or more than one course of treatment if their productive lifecycle is less than one year, neither the livestock concerned nor produce derived from such livestock can be sold as organic products.

The regulation also states that:

  • Growth promotersand synthetic amino-acids are prohibited (note that the use of antibiotics for growth promotion purposes have been banned in ALL farming practices in Europe since 2006)
  • Natural methods of reproduction must be used, artificial insemination is however allowed 
  • Hormones or similar substances are not permitted, unless as a form of veterinary therapeutic treatment for an individual animal 

Precision farming and animal health and welfare – is this just cutting out the people?

Precision farming is not about cutting out the people. The entire theory of precision livestock farming, even though it interacts with technology, is based on improving and optimising the farmer’s daily tasks. This includes paying attention to the health and welfare of the animals as well as productivity.  

Terminology like digitalisation and precision farming may sound futuristic and make people think of farming systems where everything is done by machines, but that is not the case. Precision farming is actually about finding ways to help make the farmer’s job easier and more precise, through the use of technology available. 

From the outset the entire theory of precision livestock farming is based on improving and optimising the different procedures that the farmer goes through every day. This includes a number of different elements such as paying attention to the health and welfare of the animals, monitoring resource use and productivity, etc. It also allows for data collection and sharing. This is one reason why EU farmers and partners adhere to the EU Code of Conduct on Agricultural Data Sharing.

Emerging smart technology has the potential to improve the farmer’s ability to spot and treat animal illness before it becomes a full-blown outbreak that can cost the lives of hundreds of animals, and completely devastate a farmer’s livelihood. Use of smart technology creates a potential for spotting early signs of illness.Through continuous livestock monitoring veterinarians and farmers have real-time info at their fingertips, allowing them to take action to keep diseases away from farms and from the food supply. 

New technologies could also allow farmers to maximise the efficient use of feed and other resources to avoid waste and limit the herd’s carbon footprint. 

Most importantly though, precision farming can help uphold welfare standards by measuring animals’ vital signs consistently and objectively throughout their entire lives to pick up on the first sign of any change. Researchers at KU Leuven in Belgium, for example, have developed a microphone and algorithm system using sound monitoring and analysing technology that is able to identify the sound of a pig coughing distinct from all other noises. Another example is the early detection of lameness through video analysis. As an early warning system, this means farmers and veterinarians can intervene sooner and reduce the animal’s risk of suffering from a serious, prolonged illness and reduce the eventual use of antibiotics. 

The connectivity of devices allows the system to be set up to send alerts to farmers and veterinarians either by SMS, through a web-based app or on a digital dashboard, instantly notifying them of a potential underlying health issue. And in future, the technology could also be connected to a climate controller to adapt the conditions as part of a therapeutic response to a health problem. This is why it is also important that all farmers get access to broadband internet in Europe!

What is compound feed manufacturing?

Compound feed manufacturing is a process for producing feed based on composing a safe, balanced ration of feed, using advanced animal nutrition science and feed processing technology.

Compound feed can be delivered with the purpose to serve as a complete feed, but also complementary feed, adding to feed materials available at farm level. Animal nutrition science lies at the basis of formulating the optimal feed ingredient mix to deliver protein, energy, fibre, minerals and vitamins to farm animals, meeting the farm animal’s nutritional requirements for optimal performance and health.

The key parameters of animal nutrition science used to be based on the crude content of proteins, fats and fibre. Nowadays, the indicators of animal nutritional requirements are based on digestible amino acids, bioavailability of minerals, micro ingredients (e.g. enzymes, gut flora stabilisers) and the identification and neutralisation of anti-nutritional factors. Innovative formulation can also be credited for reducing the exposure of livestock farmers to fine particles caused by the dusting potential of feed.

Compound feed processing technology has moved well beyond the simple milling and mixing of feed ingredients. The investment in heavy duty industrial equipment with high technological and “smart” power have over the years given feed manufacturers the capacity to operate specific processes with well-defined objectives. The grinding, pelleting, conditioning, coating and rumen protection all have their intended effects on animal performance, health, welfare, environment and animal product quality.

What are feed additives? Can we do without feed additives?

Feed additives are ingredients which, added in small quantities to feed, exert certain important functions. They can, for example, improve feed properties by providing nutritional value, texturise, flavour, emulsify and preserve feed. Examples that most people would recognise are vitamins, amino acids (constituents of proteins), preservatives and antioxidants, among others.

When it comes to farm animals, a great part of their diet usually consists of maize, wheat and soybean meal. In order to avoid possible deficiencies and to ensure the assimilation of all the essential nutrients, feed additives are needed. These ingredients play a key role in guaranteeing appropriate animal nutrition and, therefore, the animals’ health and well-being. 

Feed additives, however, provide other numerous benefits. In fact, among other things, they can reduce the environmental footprint of animal farming as well as supporting animal welfare, improving their resistance to infectious diseases. 

Feed additives are ingredients which are added in very small quantities to feed (in the range of milligrams per kilogramm) in order to exert specific important functions. Furthermore, some of these ingredients are essential, which means that animals are unable to synthesise them by themselves and will thus be deficient of these essentials ingredients if not included to their diet. Feed additives can also, for example, improve feed properties by enhancing their nutritional value, or improve their flavour, texture as well as help conserve their quality, freshness and wholesomeness. Ingredients that most people would recognise are vitamins, carotenoids, amino acids (constituents of proteins), salts and minerals.

When it comes to farm animals, a great part of their diet usually consists of maize, wheat and soybean meal. Such ingredients alone are often not able to satisfy farm animals’ needs in terms of dietary requirements of essential nutrients, necessary to guarantee their good health and their welfare. Therefore, in order to avoid possible deficiencies, feed additives are needed.

Nourishment, however, is not the only function feed additives exert to preserve and support animals’ health and welfare. Some ingredients, such as flavourings and colourants, can stimulate animals’ appetite during delicate periods (like with humans), as could be observed during weaning. Other feed additives, such as probiotics help maintain the balance of the intestinal microflora (similarly as in humans), which has been scientifically demonstrated to boost their immune system. Overall, these functions strengthen animal health and reduce the potential to succumb to harmful micro-organisms and become sick.

Feed additives can also improve the handling and/or hygiene characteristics of the feed.  Most important is the conservation of the quality and nutritive value of the feed, which contributes to the quality of the final animal products. In order to produce healthy food for humans, farm animals need safe, nutritious, wholesome and good quality feed.

Finally, certain feed additives can play an important role in alleviating some societal concerns, especially with regards to sustainability. Enzymes, for example, have been demonstrated to reduce emissions from livestock production (e.g. phosphorus, methane), reducing the environmental footprint.

Can any ingredient be used as a feed additive?

No; to be allowed on the EU market as a feed additive, an ingredient has to undergo a series of meticulous technical and scientific evaluation in the EU before it is allowed to be fed to animals. These assessments ensure that all additives are safe not only for the animals themselves, but also for those handling the feed, for the consumers of animal products, as well as for the environment.

For a feed additive market authorisation, companies have to submit a scientific dossier to the European Commission, who then asks the European Food Safety Authority (EFSA) to undertake a risk assessment. EFSA will evaluate the data on the quality, safety and/or efficacy of the product in the target animals, as well as the safety for the users, consumers and any potential impact of its use on the environment. At the same time, analytical methodology and samples of the products are provided to the European Union Reference Laboratory (EURL), which makes its own scrutiny. In a next step, if the outcome of the scientific risk assessment is positive, the additive has to be approved by the European Commission through an authorising regulation, which specifies the conditions or restrictions of use (e.g. minimum or maximum dose, animal species) and other specifications. Any modifications in the conditions of use need to be evaluated again before they can be introduced.

The outcome of the scientific evaluation and the authorising regulation are all made publicly available on the EFSA and European Commission websites, e.g. the EU Register of Feed Additives.

Thus, the EU authorisation procedure is based on risk assessment, risk management and risk communication, providing a structure guaranteeing transparency and food safety.  

Can we do without feed additives?

The need for healthy and sustainable animal nutrition is higher than ever before, especially as there have been fundamental developments in the knowledge on the dietary requirements of livestock. In the past, the main intention was to protect animals from potential nutritional deficiencies. Nowadays the focus has been broadened to include the assurance of welfare of the animals, as well as the support of ecology and economy.

Abandoning the use of feed additives would have severe negative consequences for the animals, the environment and for consumers of animal products. A world without feed additives could mean, in most cases, the need to use more ingredients to make up for essential nutritional factors. This would imply, in addition to dealing with the consequences of supplying feed that is unnecessary and which could lead to overeating and sickness, the use of more land, water and energy thereby increasing the environmental footprint linked to raising animals. Sustainable farming requires feed additives that contribute to an improved feed conversion ratio for a more efficient use of land, water and energy.

Feed additives are also used for improving the hygiene characteristics (wholesomeness), and to preserve the quality (and safety) of feed itself, as well as its nutritive contents: without additives there would be more spoilage and also (serious) health risks caused by undesirable molds and bacteria.

Feed additives also aid the animals’ digestion of feed and/or enable a more efficient use of the nutrients present in the diet. The absence or lack of availability of such essential components would make animals more susceptible to harmful micro-organisms and may lead to nutrient deficiencies. As animals are not able to synthesize some essential nutrients, like humans, these need to be provided. For example, a lack of carotenoids in an animals’ diet is reported to lead not only to lower vitality and yields, but also reduced fertility, birth of sickly animals which are more prone to disease and higher mortality rates. Feed additives are therefore important to meet the functional and nutritional needs of animals, as well as maintaining their health and welfare.

You can learn more about the specific benefits of certain ingredients in animal nutrition by visiting the following links:

- Carotenoids in Animal Nutrition, FEFANA
- Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 September 2003 on additives for use in animal nutrition

Does using industrial compound feed cause animal health problems?

No. Regardless of whether it concerns compound feed or any other feed, the primary element to not causing animal health and welfare problems through feed is to make sure it is safe. Indeed, good animal health includes access to nutrition containing all necessary macro- and micronutrients that support health.

European compound feed producers have to adhere to a strict and elaborate regulatory framework that imposes requirements to ensure animal feed is safe, both for the animals and the animal products consumed by people. 

A precondition for animal health and welfare is that the animal gets a diet containing all necessary macro- and micronutrients it requires. This is what compound feed is primarily designed for. In addition, compound feed manufacturers apply all the knowledge that advanced animal nutrition science has to offer in order to formulate feed that fits the livestock farmer’s health management strategy to enhance the animal health status and prevent the need for veterinary treatment.  

In the context of producing feed for ruminants, particularly dairy cattle, compound feed producers often deliver a “power feed” concentrate. This ‘complementary feed’ usually aims to compensate for suboptimal nutritional levels in roughages (particularly during winter) and is by no means produced to force an animal’s performance beyond its capacity[ref]Overview EU legislation related to animal feed production -[/ref]. 

Links to further material:
The Role of Animal Nutrition in Animal Health Management -