Meat and bone meal

IMPORTANT INFORMATION: This datasheet is pending revision and updating; its contents are currently derived from FAO's Animal Feed Resources Information System (1991-2002) and from Bo Göhl's Tropical Feeds (1976-1982).

Datasheet

Description

Click on the "Nutritional aspects" tab for recommendations for ruminants, pigs, poultry, rabbits, horses, fish and crustaceans

Common names

Meat and bone meal, bone and meat meal, meat meal, slaughterhouse by-product meal, processed animal proteins [English]; farine de viande et d’os, farine de viande [French]; harina de carne y huesos, harina de carne [Spanish]; farinha de carne e ossos, farinha de carne [Portuguese]; Fleischknochenmehl, Fleisch- und Knochenmehl, Fleischmehl [German]; farina di carne e ossa, farina di carne [Italian]; vleesbeendermeel, vlees- en beendermeel [Dutch]; kød- og benmel [Danish]; kött- och benmjöl [Swedish]; kjøttbeinmel [Norwegian]; mączka mięsno-kostna [Polish]; мясокостная мука [Russian]; м’ясо-кісткове борошно [Ukrainian]; месно-коштано брашно, mesno-koštano brašno [Serbian]; مسحوق اللحم والعظام، مسحوق اللحم والعظم [Arabic]; 肉骨粉 [Chinese]; 肉骨粉（にくこっぷん）[Japanese]; 육골분 [Korean]; मांस और अस्थि चूर्ण [Hindi]; இறைச்சி மற்றும் எலும்புத் தூள் [Tamil]; tepung daging dan tulang [Indonesian]; bột thịt xương [Vietnamese]; เนื้อและกระดูกป่น [Thai]; vleis-en-beenmeel [Afrikaans]; ukutya kwenyama namathambo [Xhosa].

Related feed(s)

Description

Meat and bone meal (MBM) is a rendered animal by-product made from animal tissues that are not used for human food: bones, carcass trimmings and other tissues from slaughter and meat processing. It is rich in protein and minerals, particularly calcium and phosphorus (Wilkinson et al., 2021; Lee et al., 2025). MBM has been used as an ingredient in animal feeds since the 19th century, and it became a staple of livestock feeding in the second half of the 20th century, as a source of valuable protein rich in essential amino acids. MBM has been used in all livestock species, including ruminants, notably in countries lacking a local production of soybean meal. The percentages in the diets were often low: less than 6% in poultry, 4% in pigs, and 1% in ruminants in France (Sauvant, 2001).

In 1986, bovine spongiform encephalopathy (BSE), a fatal prion disease of cattle, was recognised in the United Kingdom. Recycling infected bovine tissues through MBM in cattle feed amplified the epidemic, and the subsequent link with variant Creutzfeldt–Jakob disease in humans made BSE a major food safety crisis (the "mad cow crisis") (Lee et al., 2025; Woodgate, 2023). The United Kingdom banned MBM in ruminant feed in 1988, followed by France in 1990 and the European Union in 1994. These measures reduced transmission, but cases continued to occur in animals born after the bans, largely because cattle feed could be contaminated by feed containing MBM intended for pigs or poultry. This led to wider feed bans, including an EU-wide ban on processed animal proteins in feed for farmed animals in 2001 (European Parliament and Council of the European Union, 2001; Ducrot et al., 2013).

The initial bans were relaxed as BSE declined and controls on raw materials, processing and species identification improved. Selected non-ruminant animal by-products processed with methods meant to destroy the infectious agents have been gradually reintroduced into feed. In the EU, this included their reintroduction into aquaculture feed in 2013 and the authorisation in 2021 of pig-derived animal by-products in poultry feed and poultry-derived ones in pig feed, subject to safeguards against cross-contamination and intra-species recycling (European Commission, 2021).

In the European Union, three categories of animal by-products were defined in 2009 depending on the risk they pose (European Parliament and Council of the European Union, 2009; European Commission, 2011).

Category 1 (high risk) includes animals infected or suspected of infection with BSE or other transmissible spongiform encephalopathies; specified risk materials, such as certain brain and spinal cord tissues. These products can only be used for incineration and energy production and are not permitted in animal feed or fertilisers.
Category 2 (intermediate risk): animals that died on farms (fallen stock); manure; digestive tract contents; animal products containing excessive residues of certain authorised substances or contaminants. These products can be used for incineration, energy recovery, biogas, composting and organic fertilisers under specified processing conditions. They are not permitted in ordinary livestock feed.
Category 3 (low risk): slaughterhouse by-products from animals fit for slaughter for human consumption; meat and organs not marketed for human consumption; certain bones, blood, hides, feathers and former foodstuffs. Called processed animal proteins (PAP), these products can be used pet food, authorised livestock feeds, fertilisers, biogas and other products, and they remain to subject to specific restrictions.

In EU terminology, PAP means animal protein derived entirely from Category 3 material treated in accordance with regulated methods. They include proteins derived from terrestrial animal tissues as well as blood meal and fish meal. PAP differs from meat and bone meal, defined as protein produced by processing Category 1 or Category 2 materials (European Commission, 2011). In the current (2026) EU framework, only PAP can be fed to livestock, with important limitations: PAP from mammalian species can only be fed to pigs and poultry, and PAP from ruminant species can only be fed to pets and fur animals.

In the United States, the feed ingredient definition specifies mammalian tissues including bone, without added blood, hair, hoof, horn, hide trimmings, manure or stomach and rumen contents, apart from unavoidable traces arising during good manufacturing practice (Wilkinson et al., 2021). AAFCO definitions define separately meat meal and meat and bone meal. The latter explicitly includes bone and must contain at least 4% phosphorus, whereas no minimum phosphorus content is specified for meat meal. The definition of meat meal does not exclude the presence of bone. In practice, meat and bone meal generally contains more ash, calcium and phosphorus, and less crude protein than meat meal, reflecting its higher proportion of bone material. Both products are subject to the same maximum calcium-to-phosphorus ratio of 2.2:1 and the same limits on pepsin-indigestible material (AAFCO, 2002).

Meat and bone meal is a variable commodity. Its composition depends on the animal species and tissues processed, on the relative proportion of bone, and on the rendering and fat-separation methods. Variation may occur between plants and between batches from the same plant (Dilelis et al., 2021; Pérez-Calvo et al., 2010). Product names and definitions should therefore be interpreted in their regulatory and commercial context (Wilkinson et al., 2021). Currently, the nature and the permitted uses of MBM depend on the origin and classification of the material and on local rules (Woodgate, 2023; Lee et al., 2025).

Distribution

Meat and bone meal originates from the slaughtering and meat-processing industries and is thus available worldwide. Its supply and quality is linked to the number and species of animals slaughtered and to the collection and rendering of their by-products. Raw materials are highly perishable and require prompt processing, favouring the location of rendering activities within reach of slaughterhouses and other collection points (Ash, 1992; Downing, 2026; Woodgate, 2023).

Production figures in million tonnes

Producer	Year	Production	Remark	Source
United States	2025	2.2	MBM (excluding poultry by-product meal)	Downing, 2026
Europe	2025	2.9	All PAPs from members of the EFPRA (not strictly EU)	Prykhodko, 2026
Brazil	2026	4.0	All land animal by-products	ABRA, 2026
Australia	2015	0.3	Excluding poultry by-product meal; 50% is from ruminants	ARA, 2016

Note that these figures are not directly comparable as they do not include the same types of materials.

The resulting meals enter both domestic markets and international trade. Here are the main exporters of MBM according to the UN Comtrade Database for the UN Harmonized System code 230110: Flours, meals and pellets; of meat or meat offal, greaves (United Nations, 2026).

Exportation figures in million tonnes for 2025

Rank	Exporter	Export	Share (%)
1	European Union	2.05	43.86
2	United States	1.10	23.53
3	Brazil	0.41	8.69
4	Australia	0.35	7.47
5	United Kingdom	0.25	5.32
6	Argentina	0.15	3.16
7	New Zealand	0.15	3.11
8	Canada	0.13	2.86
9	Paraguay	0.06	1.28
10	Norway	0.03	0.71

Availability for livestock feeding is smaller than total rendered meal production might suggest. Species segregation, processing capacity, price and demand from pet food manufacturers affect the volume offered to feed manufacturers. The origin and risk category of the material also determine whether a rendered meal enters feed, fertiliser or energy markets (Dzwonkowski, 2021; Woodgate, 2023). In the case of Europe's EFPRA members, for instance, about 75% of the PAPs went to petfood in 2025, with a 16% increase since 2015 (Prykhodko, 2026)

Processes

Yield

The yield of MBM from slaughtered animals was estimated in the US to be about 16.8 kg of meat and bone meal from a steer weighing 454 kg and about 3.2 kg from a pig weighing 109 kg, equivalent to approximately 3.7 % and 2.9 % of live weight, respectively (Ash, 1992).

Rendering

Rendering separates animal by-products into a fat fraction and a protein-rich solid fraction. The raw material is reduced in size and heated to remove water and release fat. Fat is separated from the solid fraction, which is ground to make a meal. Rendering may be carried out in batch or continuous systems, and processing conditions differ among plants (Woodgate, 2023; Wilkinson et al., 2021). Heating helps control microorganisms, but process conditions also affect product quality. In a study of two rendering plants in Spain, differences in raw materials, processing conditions and fat removal contributed to variation in the meals; the more severe heat treatment was associated with a reduction in the ratio of reactive to total lysine and in pepsin digestibility (Pérez-Calvo et al., 2010).

Product safety

Since the BSE crisis, international and national authorities have defined processes to reduce the infectivity of any transmissible spongiform encephalopathy agent present in animal by-products. The general recommandation of the World Organisation for Animal Health are as follows (WOAH, 2022):

The raw material should be reduced to a maximum particle size of 50 mm before heating.
The raw material should be heated under saturated steam conditions to a temperature of not less than 133°C for a minimum of 20 minutes at an absolute pressure of 3 bar.

In the European Union, PAP meant for livestock feeding must have undergone one of the following treatments, as described in Commission Regulation (EU) No 142/2011, Annex IV, Chapter III, methods 1–7, consolidated version of 29 October 2025, pp. 48–50 (European Commission, 2011).

Method	Maximum particle size	Core temperature and minimum time	System and other conditions
1: Pressure sterilisation	50 mm	>133 °C for at least 20 minutes, without interruption	At least 3 bar absolute pressure, produced using saturated steam after evacuation of air. Batch or continuous. Heat treatment may be the sole process or a pre- or post-process sterilisation phase.
2	150 mm	>100 °C for at least 125 minutes; >110 °C for at least 120 minutes; and >120 °C for at least 50 minutes.	Batch only.
3	30 mm	>100 °C for at least 95 minutes; >110 °C for at least 55 minutes; and >120 °C for at least 13 minutes.	Batch or continuous.
4	30 mm	>100 °C for at least 16 minutes; >110 °C for at least 13 minutes; >120 °C for at least 8 minutes; and >130 °C for at least 3 minutes.	Material is heated in a vessel with added fat. Batch or continuous.
5	20 mm	After coagulation and pressing: >80 °C for at least 120 minutes and >100 °C for at least 60 minutes.	Material is first heated until it coagulates, then pressed to remove fat and water from the proteinaceous material. Batch or continuous.
7: Authorised process	Determined for the authorised process.	Determined for the authorised process.	The operator must identify relevant hazards, demonstrate that the process reduces them to an acceptable level, and meet microbiological standards (testing for Clostridium perfringens, Salmonella and Enterobacteriaceae) through daily sampling over 30 production days. Particle size, critical temperature and time must be recorded and monitored. The competent authority must authorise the proces.

For methods 2–5, all listed time–temperature requirements apply; the periods may be achieved consecutively or overlap. Particle-size reduction equipment must be checked daily, its condition recorded, and processing stopped and equipment repaired if oversized particles are found.

Method 7 provides a route for approving a process tailored to the material and its hazards. The operator proposes a method and must demonstrate to the competent authority that it reduces the identified risks to a level that poses no significant risk to public or animal health.

Environmental impact

Rendering recovers proteins, fats and minerals from animal tissues that would otherwise require another form of treatment or disposal. Their use in feed, pet food, fertilisers and energy production can conserve resources by replacing other products, although the environmental benefit depends on the material recovered, its processing and the use that it replaces (Wilkinson et al., 2021; Woodgate, 2023; Lee et al., 2025). Feed-grade processed animal proteins (PAP) should be distinguished from higher-risk meat and bone meal directed to fertiliser or energy uses, since these streams differ in their raw materials and permitted applications (Woodgate, 2023).

Energy use and greenhouse gas emissions

Rendering requires heat to cook and dry the raw material, as well as electricity for processing equipment. In the United Kingdom, a life-cycle assessment of mammalian rendering showed that greenhouse gas estimates depended strongly on the use of natural gas or rendered fat as process fuel. The base-case estimate for PAP was 0.15 kg CO₂-equivalent per kg of product for fossil emissions. Raw animal by-products were treated as wastes carrying no upstream livestock-production burden, and the system included the use of rendered fat as fuel; the estimate therefore describes that particular modelling approach (Ramirez et al., 2012).

Studies that assign some livestock-production impacts to the raw materials can give different results. An assessment of two poultry-rendering units in Portugal reported 726 kg CO₂-equivalent per tonne of poultry by-product meal delivered to the feed producer, using economic allocation, which divides impacts according to product value. Process heat was a major contributor to climate impact, and assigning impacts by mass instead of value increased the estimates. These results concern poultry by-product meal and should not be transferred directly to mammalian meat and bone meal (Campos et al., 2020).

Consequently, comparisons between ingredients need consistent boundaries and allocation rules: whether livestock production is included, how impacts are divided between meat and by-products, the fuel used, and the products assumed to be displaced can all affect the conclusion (Ramirez et al., 2012; Campos et al., 2020; Al-Zohairi et al., 2023).

Industry assessments of carbon and water footprints

EFPRA's Sustainability Charter promotes recovery of animal by-products as part of a circular bioeconomy (EFPRA, 2021). Its subsequent white paper and case study present an industry-commissioned assessment by Mérieux NutriSciences | Blonk, using data from 48 European rendering production lines in 2020–2022. The published results use economic allocation and include farming, slaughter, transport to rendering and rendering, ending at the rendering-factory gate (EFPRA, 2024a; EFPRA, 2024b). Under these assumptions, EFPRA reports lower carbon footprints for rendered meals than for the soybean-meal market mix selected for comparison. Much of the upstream livestock burden is assigned to meat, while land-use-change emissions contribute to the soybean result. The white paper states that the plant-based comparators rely mainly on secondary database information and should be regarded as benchmarks rather than definitive comparisons (EFPRA, 2024a; EFPRA, 2024b).

The EFPRA assessment reports water use of approximately 6.6–15.3 litres per kg of PAP or meal from cradle to rendering-factory gate. In its comparisons, rapeseed meal used less water than rendered meals, while soybean meal used more; conclusions also depended on whether the comparison was expressed per kg of ingredient or per kg of protein (EFPRA, 2024b).

Recovery of feed resources and choice of use

Returning suitable animal proteins and minerals to feed can reduce demand for other protein and mineral sources (Lee et al., 2025). However, the preferred recovery route depends on the comparison made. A study using data from four European pig slaughterhouses found that increasing the proportion used as human food reduced impacts per kg of pork sold. Among the modelled uses of remaining by-products, pet feed performed better than biofuel and biogas (Al-Zohairi et al., 2023).

For aquafeed production in Italy, a life-cycle assessment estimated a 66.0 % reduction in climate impact per kg of a gilthead seabream feed formulated with poultry by-product meal relative to a fishmeal-based reference feed. The formulations also differed in other ingredients and their supply chains. This is therefore a result for the complete feed-production scenarios, ending at the feed-production gate, rather than an isolated effect of replacing fishmeal or a reduction demonstrated per kg of fish produced (Tignani et al., 2024).

Alternative treatment systems can also offer environmental benefits. A US study comparing slaughterhouse-waste rendering with anaerobic digestion found that digestion and co-digestion could perform better when credits for displaced energy and fertilisers were included. Methane leakage and the amount of mineral nitrogen fertiliser displaced were particularly influential (Wang et al., 2021).

Fertiliser use and nutrient losses

Meat and bone meal can recycle nitrogen and phosphorus to cropland, but its nutrient ratio may not match crop requirements. In Norway, a laboratory column experiment with bare soil showed that nitrogen mineralised from meat and bone meal could be lost through leaching before crop uptake; phosphorus losses were smaller, but increased with application rate. The findings support matching the rate and timing of application to crop demand rather than applying meal solely to meet nitrogen requirements (Jeng et al., 2009).

In a six-year field experiment in north-eastern Poland, an annual application of 1.0 tonne of meat and bone meal per ha, supplying 45.0 kg P/ha/year, met the phosphorus needs of a maize, wheat and oilseed rape rotation comparably to mineral phosphorus fertiliser at the same P rate. Higher annual inputs supplying 68.0 or 90.0 kg P/ha resulted in excessive phosphorus accumulation in the soil. Nitrogen and potassium supply were controlled across the fertilised treatments, so the comparison does not show that meal alone supplied all crop nutrients (Załuszniewska et al., 2022).

Soil conditions and processing also affect the environmental consequences of fertiliser use. In the Netherlands, a three-month laboratory incubation of sandy and loam soils found that nitrous oxide emissions from the animal-derived amendments tested, including meat and bone meal, did not exceed those from calcium ammonium nitrate. Emission patterns nevertheless varied with soil and amendment, so the result does not establish a general field-emission advantage for meat and bone meal (Cayuela et al., 2010). In Italy, a soil-incubation study found that alkaline thermobaric hydrolysis increased nitrogen availability from meat and bone meal without improving phosphorus availability or significantly changing carbon mineralisation (Ciurli et al., 2026).

Fertiliser recycling also involves trade-offs between impact categories. In a Swedish life-cycle assessment of Category 2 meat meal, recovering nutrients for crop production reduced greenhouse gas emissions and acidification relative to a system recovering energy and using chemical fertiliser, but increased total energy use and eutrophication impacts. The result depended strongly on the fuels displaced (Spångberg et al., 2011).

Combustion and local emissions

Combustion provides an outlet for meals that cannot be used in feed, recovering energy and leaving a phosphorus-rich ash (Woodgate, 2023). Its environmental performance depends on energy inputs and the heat, electricity or other products credited as replacements: an assessment of two Polish combustion technologies changed their relative ranking when avoided environmental burdens were included (Kowalski et al., 2021). Tests of a rotary combustion system showed that energy recovery could be combined with compliance with the air-emission limits examined (Bujak et al., 2020).

In China, laboratory experiments showed that meat and bone meal incineration ash could remove phosphate from synthetic wastewater and subsequently serve as a phosphorus-recovery material (Leng et al., 2019).

Rendering can also cause local odour nuisance. At a plant in southern Brazil, the biofilter tested did not achieve the odour-removal benchmark used by the researchers, indicating a need for improved biofiltration or additional treatment (Vieira et al., 2016).

Nutritional aspects

Nutritional attributes

Meat and bone is an excellent source of supplemental protein and has a well-balanced amino acid profile. Digestibility of the protein fraction is normally quite high, ranging from 81 to 87% (Kellems et al., 1998). It is well suited for use in feeding monogastric and provides not only a well-balanced protein source, but also a highly available source of calcium and phosphorus. Excessive heating during processing will reduce the digestibility of the protein fraction. Limiting amino acids for swine when combined with cereal grains are lysine, methionine and threonine and for poultry it is methionine and cystine (Kellems et al., 1998). Meals that have higher protein content, often contains blood and isoleucine may become the first limiting amino acid. The protein quality is lower than fish meal or soybean meal for applications in feeding swine or poultry when used to supplement protein in cereal based diets. Processing temperature was higher correlated with lysine availability, as the temperature increased the lysine availability declined (Batterham et al., 1986).

In addition to the protein (amino acids) meat and bone meal is an excellent source of calcium and phosphorus and some other minerals (K, Mg, Na, etc.). The ash content of the meat and bone meal normally ranges from 28 to 36 %; calcium is 7 to 10 % and phosphorus 4.5 to 6 %. When using meat and bone meal as the primary supplemental protein source the mineral levels may limit its use in some diet formulations. Meat and bone meal like with other animal products is a good source of Vitamin B-12.

Potential constraints

Legal status on the use of meat and bone meal

The legal status of meat and bone meal (MBM) depends on the species of origin, the animal species to be fed, the material’s legal classification and its intended use. There is no single worldwide authorisation or prohibition. The examples below illustrate rules verified for selected jurisdictions; they do not constitute an exhaustive inventory of national legislation. The principal common control is to prevent ruminants from consuming ruminant-derived protein meal, while rules for non-ruminant feeds vary by country, source species and processing status. For feed classification and use, the product’s origin and legal category are essential: a rendered product called "meat and bone meal" (MBM) in trade may not correspond to a legally defined processed animal protein (PAP), and the same species of origin may be allowed for one livestock species but prohibited for another. Feed bans also need to be distinguished from restrictions on manufacture, import, fertiliser use or disposal.

International framework

The World Organisation for Animal Health (WOAH) Terrestrial Animal Health Code addresses bovine spongiform encephalopathy (BSE), including the risk associated with ruminant-derived protein meal and controls to prevent contaminated feed reaching cattle. These international standards inform animal-health measures and trade but do not themselves establish a uniform domestic feed authorisation; national rules determine which materials may be manufactured, traded and fed to each species (WOAH, 2022).

European Union

The following table summarises the EU feed-ban framework as it stood after Regulation (EU) 2021/1372 entered into force on 7 September 2021 (Schneegans, 2021; European Parliament and Council of the European Union, 2001; European Parliament and Council of the European Union, 2009; European Commission, 2011; European Commission, 2021; IPIFF, 2024).

Source and product	Ruminants	Pigs	Poultry	Farmed fish	Fur animals	Farmed insects
Ruminant PAP, including blood meal	No	No	No	No	Yes*	No
Pig PAP	No	No	Yes	Yes	Yes*	No
Poultry PAP	No	Yes	No	Yes	Yes*	No
Fishmeal	Exception†	Yes	Yes	Yes‡	Yes*	Yes
Insect PAP	No	Yes	Yes	Yes	Yes*	No

Yes means permitted subject to applicable sourcing, processing, segregation, traceability and other conditions. No means prohibited for the specified ingredient and recipient. The table concerns farmed animals; fish means farmed fish, and insects means insects farmed for food or feed.

* Fur animals are excluded from the extended TSE feed ban. The material must be eligible and comply with the animal-by-product and feed rules. The same-species restriction on PAP for terrestrial animals explicitly excludes fur animals.

† Fishmeal is permitted in milk replacers for unweaned ruminants under specified conditions; it is not generally permitted in ordinary ruminant feed.

‡ Fishmeal derived from wild fish may be used for farmed fish; material from farmed fish may be used for farmed fish of a different species, subject to the applicable conditions.

Meat and bone meal (MBM) has a specific EU meaning: it is produced from Category 1 or 2 material. It should not be substituted for Category 3 PAP in the table. Ruminant gelatine and collagen may be used in feed for non-ruminant farmed animals, while milk, egg products and certain hydrolysed proteins are subject to different rules. Non-ruminant blood products are also treated differently from blood meal. Insect-rearing substrates therefore cannot be classified solely by the source species; for example, fishmeal may be permitted while other PAPs are generally prohibited. Detailed conditions and product-specific exceptions must be checked before use.

Examples of other national rules

United States federal rules prohibit most mammalian protein in feed for ruminants, with defined exceptions and additional restrictions on specified cattle materials (Code of Federal Regulations § 589.2000 and § 589.2001) (CFR, 2026a; CFR, 2026b).
Brazil prohibits the production, marketing and use of feed for ruminants containing animal-origin proteins or fats, with specified exceptions including milk products and protein-free calcined bone meal. Labels for products containing animal-origin protein or fat intended for non-ruminants must state that use in ruminants is prohibited (MAPA, 2009).
Australia prohibits feeding restricted animal material, including MBM, to ruminants under state and territory controls (AHA, 2023).
New Zealand’s Biosecurity (Ruminant Protein) Regulations prohibit feeding ruminants protein derived from ruminants, including ruminant protein meal (MPI, 2013).
Japan permits approved porcine-origin MBM in certain non-ruminant feeds under a longstanding approval system. In 2024, following a risk assessment, Japan also authorised eligible cattle-derived MBM for specified non-ruminant feeds subject to source and processing controls. MBM remains prohibited in ruminant feed (Food Safety Commission of Japan, 2024; MAFF, 2012).

It is strongly recommended that potential users check their country's regulations to assess the current status of meat and bone meal regarding its utilization in livestock feeding.

In areas where meat and bone meal is authorized for livestock feeding, the use of proper heat treatment is required to control the spread of BSE and other disease agents such as salmonella.

Feed safety concerns other than those related to BSE

The safety of meat and bone meal (MBM) depends on the origin and condition of the raw materials, the effectiveness of rendering, and protection of the finished meal during handling, transport and storage. Control measures therefore need to cover the whole production chain, combining supplier assurance, process monitoring, good manufacturing practices and appropriate testing (EFSA, 2008; Lachapelle et al., 2024).

Microbiological contamination

Salmonella is an important microbial hazard in animal-derived protein ingredients: contaminated feed can introduce infection into livestock populations, including infections that do not cause obvious clinical signs, and can contribute to contamination further along the food chain (EFSA, 2008). Other bacteria, including Clostridium spp. and Bacillus spp., have also been detected in MBM during investigations of rendering operations (Leiva et al., 2018).

Contamination after cooking is a particular concern. In Costa Rica, Salmonella was detected in 8 of 62 MBM samples collected at different points in the production process, but was not detected immediately after cooking; the investigators identified subsequent recontamination as a major weakness in the production chain (Leiva et al., 2018). In Turkey, a survey of several types of rendered animal meal found positive samples at feed factories, whereas samples obtained from rendering plants were negative. This finding concerned the combined group of rendered meals and should not be interpreted as an MBM-specific contamination rate (Kutay et al., 2016).

Prevention requires both an effective rendering process and separation of raw materials from finished meal. Important measures include controlling personnel and equipment movements between these areas, maintaining clean conveyors and storage facilities, controlling pests and dust, and protecting vehicles and loads from contamination. Moisture ingress and condensation require particular attention because they can create conditions favourable to bacterial multiplication in an otherwise dry feed-production environment (EFSA, 2008; Leiva et al., 2018; Lachapelle et al., 2024).

A review of carcass recycling recommends timely collection and delivery of raw materials before substantial decomposition, using liquid-tight vehicles or containers to limit the spread of contamination during transport. It also emphasises sufficient storage space, plant layouts that allow effective cleaning and sanitation, and regular inspection, maintenance and upgrading of deficient processing equipment. The review further recommends proactive testing for pathogens and toxins before, during and after rendering, with monitoring extending through transport of the rendered products. These measures should be supported by good manufacturing practices, hazard analysis and critical control point (HACCP) programmes, independent food-safety certification audits, and clearly assigned responsibilities among operators involved before and after rendering (Pandey et al., 2020).

Microbiological testing should be integrated with process and environmental monitoring rather than used as the sole assurance that a batch is safe. EFSA emphasised that testing only the end product cannot reliably demonstrate the absence of contamination throughout the production chain (EFSA, 2008). Chemical treatments can provide an additional barrier: a study in the United States found that several treatments reduced Salmonella contamination in rendered protein meals, but their effectiveness depended on the treatment, the meal and the period of storage. These experimental results support evaluating a treatment for the particular product and conditions of use, rather than assuming that an additive can compensate for inadequate hygiene (Cochrane et al., 2016).

Research from Brazil proposed near-infrared spectroscopy (NIR) combined with multivariate control charts based on principal component analysis (MCC-PCA) to screen bovine MBM for changes associated with Salmonella contamination. The control charts were established using 300 Salmonella-negative samples and assessed with further negative and positive samples. The authors proposed the method as an initial screening and decision-support tool that could reduce the number of conventional analyses. They stress that NIR identifies changes associated with the presence of the bacteria, rather than detecting the bacteria themselves; its proposed role is therefore screening alongside conventional microbiological evaluation (de Marchi dos Santos et al., 2025).

Oxidation and deterioration during storage

The residual fat and proteins in MBM can undergo oxidation during processing and storage. Lipid oxidation contributes to rancidity, while protein oxidation can alter amino acids and protein structure; the extent of these changes depends on the composition of the meal and its exposure to heat and other oxidation-promoting conditions (Hendriks et al., 2006; Frame et al., 2020; Lu et al., 2025). Evidence reviewed for feeds more generally links excessive protein oxidation with reduced nutritional quality and adverse animal responses, but the consequences cannot be assumed to be identical for every MBM or storage condition (Lu et al., 2025).

In New Zealand, storage of three MBM samples for up to nine months increased lipid oxidation, and antioxidant addition reduced the measured oxidation products. However, storage did not produce a general decline in ileal amino acid digestibility in the rat assay used: methionine digestibility declined, while most amino acids were unaffected. Thus, detectable rancidity does not by itself quantify the loss of protein value or predict the response of livestock fed a complete diet (Hendriks et al., 2006). In a study in the United States, beef MBM showed increased protein oxidation after short-term storage at an elevated temperature, and the antioxidants tested did not consistently protect proteins across the different rendered meals (Frame et al., 2020).

Mitigation should combine protection from excessive heat and moisture, controlled storage duration, and antioxidants selected on evidence of their effectiveness in the particular meal. Antioxidant protection against lipid oxidation should not automatically be taken as protection against protein oxidation (Hendriks et al., 2006; Frame et al., 2020). Quality monitoring can combine lipid-oxidation measurements with protein-oxidation indicators, such as protein carbonyls, where appropriate. Results need to be interpreted in relation to storage history, because oxidation products can themselves react or break down as deterioration proceeds (Hendriks et al., 2006; Frame et al., 2020; Lu et al., 2025).

Biogenic amines

Biogenic amines can accumulate when microorganisms act on amino acids in deteriorating animal tissues. Some amines, notably histamine and tyramine, may be harmful at sufficiently high concentrations, while amine profiles can also provide information about the condition of the raw material and the quality of processing. Their occurrence and interpretation depend on the type of animal meal, and toxicological findings in human foods should not be transferred directly to livestock feeds (Feddern et al., 2019; Braga et al., 2023). In southern Brazil, analyses of bovine MBM, swine meal, poultry meal and feather meal showed differences in their free amino acid and amine profiles, both between meal types and between rendering plants. The authors proposed these profiles as supplementary indicators of identity and quality, rather than as a single universal safety criterion (Braga et al., 2023). Prevention should focus on hygienic collection and handling of animal tissues and control of delays and temperature before processing. Heating may destroy amine-producing microorganisms but does not reliably remove the heat-stable amines already formed; rendering therefore cannot restore the quality of badly deteriorated raw materials (Feddern et al., 2019).

Chemical contamination

Chemical quality also requires verification. In Bangladesh, a survey detected chromium and lead in commercial products described as meat and bone meal feed. The findings identify a need for raw-material control and chemical surveillance in that supply chain, but do not establish typical concentrations in MBM from other origins (Jothi et al., 2016). In southern Brazil, mercury concentrations in 12 bovine MBM samples ranged from 0.01 to 0.18 mg/kg as fed, illustrating that chemical contaminants can be present even in meals that meet the microbiological criteria examined in the same study (Braga et al., 2023). Practical controls include specifications for incoming materials, traceability, supplier guarantees supported by analytical results, and audits where warranted. A risk-based testing programme should reflect the origin of the material and the supplier's history, with documented corrective action when results depart from specifications. These measures complement process hygiene rather than being replaced by it (Lachapelle et al., 2024).

Preserving nutritional quality during safety control

Processing must balance microbial control with preservation of the feed's nutritional value. Excessive cooking can impair protein quality, while variation in the proportions of bone and soft tissues changes the protein, ash and mineral contents of the finished meal. Process monitoring should therefore be accompanied by composition and protein-quality checks, so that a hygienically satisfactory product is also suitable for its intended use in feed formulation (Leiva et al., 2018). An integrated HACCP programme, supported by supplier control, effective segregation, monitoring and review of analytical trends, provides a framework for managing these different risks together (EFSA, 2008; Lachapelle et al., 2024).

Ruminants

Note: feeding meat and bone meal to ruminants is restricted or banned in many countries. The research presented below was carried out before the ban was in effect. It does not constitute an endorsement of the use of meat and bone meal in ruminants.

In ruminants it can readily be used to replace most other supplemental protein sources. The crude protein is less ruminally degradable, and will pass thorough the rumen without being degraded when compared to many other supplemental protein sources. Processing temperature will also effect the availability of the protein fraction. Often pepsin digestibility of the protein fraction is used as a means of determining the extent of processing and availability of the protein fraction. Excessive heating during processing can reduce protein digestibility. Ruminal escape protein ranged from 41.7 to 51 % of CP in one study (Klemesrud et al., 1997) and 51.3 to 60.8 % in another study (Howie et al., 1996).

In ruminant species response to meat and bone meal used to replace other supplemental protein sources were mixed. Goats performed similarly when meat and bone meal replaced fish meal (Kunjikutty et al., 1992). Dietary nitrogen digestibility was found to be lower when meat and bone meal was used to replace soybean meal in diets for sheep (Lee et al., 1986). Summarization of a 127 trials where ruminally by-pass protein sources, including meat and bone meal, were fed to lactation dairy cattle, only 17 % showed an increase in milk production (Santos et al., 1998). Milk production of grazing lactating dairy cattle was increased when supplemented with meat and bone meal (Davison et al., 1990). Methionine is considered to be the limiting amino acid in ruminant applications (Klemesrud et al., 1997).

Pigs

Meat and bone meal when fed to swine lowered performance when replacing soybean meal (Kennedy et al., 1974a; Partanen et al., 1998) and other reports observed no differences (Gomes et al., 1982). When it replaced fish meal performance was found to be similar in swine (Mishev et al., 1981). It was found to be superior to feather meal when used in swine ration formulations (Kalous et al., 1981). Feed conversion and nitrogen digestibility was lower for meat and bone meal as compared to soybean meal in feeding applications in swine (Kennedy et al., 1974b). Efficiency of nutrient utilization decreases as dietary level increases in swine (Partanen et al., 1994).

Poultry

When meat and bone meal replaced fish meal in broiler chicks diets growth was similar, but feed conversion was lower (Al-Mulsi, 1998). Up to 10 % replacement levels for soybean meal in chick diets showed no differences in gain and feed conversion (Leitgeb et al., 1998). In turkeys diets meat and bone meal replaced 20 to 60 % of the soybean meal with no effect on performance (Robaina et al., 1997). Efficiency of nitrogen utilization as compared to soybean meal was less for meat and bone meal in broilers (Kim et al., 1993).

Fish

Note: feeding meat and bone meal to fish is restricted or banned in many countries.

Rainbow trout (Oncorhynchus mykiss)

Digestibility of protein was relatively high (83-89 %) and energy digestibility was lower in trout (68-83 %)(Bureau et al., 1999).

Tilapia

Growth was similar in tilapia when meat and bone meal was fed, but feed conversion and the Protein Efficiency Ratio were lower (El-Sayed, 1998).

Hybrid striped bass (Morone saxatilis X Morone chrysops)

Crude protein digestibility was similar and energy digestibility was higher than soybean and cottonseed meals in striped bass (Sullivan et al., 1995).

Nutritional tables

Tables of chemical composition and nutritional value

Avg: average or predicted value; SD: standard deviation; Min: minimum value; Max: maximum value; Nb: number of values (samples) used