Recycled manure solids

Published 9 September 16

Defra, the Welsh Government and the Scottish Government will continue to permit the use of RMS as bedding for dairy cattle provided farmers comply with certain conditions and follow best practice management criteria. These conditions have been agreed by Defra, Welsh Government and Scottish Government in consultation with industry stakeholders to mitigate any potential risks to public and animal health, provide guidance to farmers, and to protect the reputation of the industry. The conditions are available to download here.

Should new research identify any further risks to public or animal health that cannot be sufficiently mitigated by amendments of the conditions, then farmers must be aware that Defra, the Welsh Government and the Scottish Government may no longer permit the use of RMS as bedding material under the EU Regulation.

Background

Virtually all dairy cows are housed at some stage during the year, not least to provide protection from inclement weather over the winter months. While the animals are housed, the use of safe, comfortable, dry bedding is an important consideration for good health and welfare. Materials used typically include, straw (whole or chopped), synthetic cubicle mattresses, sand, sawdust, wood shavings, and a variety of proprietary products.

Increased costs and reduced availability of bedding sources has prompted many dairy farmers to search for more accessible, cost effective and sustainable alternatives. Interest in using separation technology, to produce recycled manure solids for bedding (RMS, commonly referred to as ‘Green Bedding’), has been increasing in many countries around the world. For example, this has become common practice in many US herds, and is also being used in several European countries.

The advantages claimed include increased cow comfort relative to other bedding materials, reduced cost and increased environmental sustainability. An increasing number of British farmers have been considering whether to use this technique to provide bedding for their own herds.

EU regulation

Current users and those considering using RMS as bedding need to be aware of the legal requirements. Livestock manure is classified as a Category 2 animal by-product under the EU Animal By-Products (ABP) regulation (EU 1069/2009). As such, the ABP regulation does not directly permit the use of manure, as bedding. However, the regulation has provisions which permit animal by–products and derived products to go for technical uses provided these do not pose an unacceptable risk to public or animal health. Therefore, farmers using recycled manure solids as bedding have to ensure they control risks to public and animal health.

Defra, the Welsh Government and the Scottish Government are of the view that if RMS is used for cattle bedding in accordance with prescribed conditions, there will be no unacceptable risks to public and animal health. These conditions are based on the latest research into RMS use on farms in England and Scotland.  

If at any point, unacceptable risks emerge that cannot be sufficiently mitigated through changes in practices or management, Defra and the devolved administrations may no longer permit the use of RMS as bedding. This fail safe is essential to ensure the good reputation of the dairy industry and consumer confidence in its production methods, are maintained. Defra and the devolved administrations will review the current position in summer 2017. 

What are the controlled conditions I must comply with? 

The requirements in this section must be followed at all times. By complying with these conditions you can ensure that action will not be taken against you under the Animal By-Products and Animal Welfare regulations. Requirements are either based on the need to mitigate risks to an acceptable level as required under regulation or a consensus agreement by industry stakeholders about good management practice.

 1. RMS must only be produced using raw cattle manure/slurry from housing and/or yards

Manure from other livestock species must not be included for the production of RMS, to avoid introducing external pathogens which may affect cattle health.

 2. RMS must only be used as bedding for cattle which are in the same epidemiological unit as those cattle from which it is generated 

To minimise the risk of disease transfer, RMS must only be produced on the unit on which it is to be used and only from slurry originating from that unit. Slurry or manure must not be moved between units either before or after separation. An epidemiological unit comprises animals which come into contact with each other directly or indirectly (e.g. shared facilities or personnel) as part of the same farm business. They may not necessarily be housed on the same site or premises. 

3. RMS must be produced from a slurry separator unit, designed for the purpose, which produces manure solids of at least 34% Dry Matter 

Slurry is mechanically separated into a liquid fraction and a “solid” fraction, typically by using a screw or roller press action. The equipment needs to be capable of extracting sufficient water to make the solid fraction at least 34% dry matter. If the material is too wet (below 34%) it is unsuitable for use as bedding 

4. Material that has been composted or digested must not be used 

The spores of certain bacteria, particularly those that are heat-resistant may be encouraged by composting. Too high a concentration of spores can lead to losses during the manufacture of cheese and reduce the shelf life of pasteurised milk. 

Putting manure through a digester will also increase temperatures, which can affect pathogen load. Until further information is available, use of RMS produced from the output of a digester is not permitted. Equally, use of digestate which contains feedstock from non-farm sources could cause an additional unacceptable risk, and must not be used. 

RMS must be used within 12 hours of its production to avoid composting or anaerobic digestion of the material and significant change to its nature and microbiological composition. 

5. RMS must not be produced from manure/slurry of herds which are subject to official restriction for notifiable diseases, (see below for TB specific conditions) 

A list of notifiable diseases is available here. The main notifiable disease of concern is foot and mouth disease, as the infective agent can occur in faeces and urine up to four days before clinical signs appear. 

6. Manure from TB Inconclusive reactors and TB reactors must be excluded from the use of RMS 

Unless TB is advanced in an animal, there are unlikely to be large numbers of organisms shed in faeces. However, as yet the specific risk of TB spread though manure/slurry has not been quantified.  With regular testing, the chances of reaching this stage of infectivity are much reduced. However, if TB were present in slurry, it is not likely to be reduced by physical separation. Therefore, RMS may only be made and used in herds that are Officially Tuberculosis Free (OTF) for bovine TB. RMS made from manure/slurry originating during a period of non-OTF status is potentially contaminated and must not be used after OTF status is regained. 

7. The production and use of RMS must be suspended if animals on farm show clinical signs of infection or have tested positive for enteric pathogens or outbreaks of clinical disease (e.g. Salmonella, VTEC etc) 

8. RMS must not be produced from slurry/ manure of cattle that are undergoing treatment for disease. 

Using antibiotics and dry cow therapy responsibly are an essential element in the fight against animal disease. However, there are concerns over an increased risk of antibiotic resistance developing in manure being recycled for bedding. Every effort should be made to take the slurry to be processed for RMS from groups where no or minimal numbers of cows currently being treated with antibiotics. You may want to consider putting a protocol in place to ensure  slurry/manure from cows under treatment or withdrawal can be kept separate from the rest of the herd e.g. using a quarantine/isolation pen. In the event that all cattle or a significant proportion of the herd are being treated with antimicrobials, then their slurry/manure should not be used to produce RMS during the treatment and withdrawal period. 

9. RMS must not be produced from manure/slurry produced in quarantine pens

Bought-in cattle are likely to have different faecal flora and also immune status, so they could introduce new pathogens and also be more susceptible to those endemic in the herd. 

10. Manure from aborted cattle under brucellosis investigation must be excluded from use as RMS 

On farms where RMS are being used for bedding, rigorous biosecurity is even more important in relation to suspected brucellosis cases as it is a zoonosis. 

11. Other materials, such as birthing fluids and placental material, manure from calving areas, and waste milk must not be disposed of by adding these to manure/slurry going for RMS 

Afterbirth and other fluid materials are a potential risk for disease transmission. Waste milk, subject to withdrawal period, must not be added to the slurry pool, as there is an increased risk of developing antibiotic resistance and increased risk for MAP. Anecdotally, inclusion of waste milk in material used for bedding has been associated with increased cell count/mastitis problems. 

12. RMS must only be used as bedding for housed cattle over twelve months old 

Regulations on calf health and welfare (Council Directive 2008/119/EC and the Welfare of Farmed Animals Regulation 2007) state that calves must have access to a lying area which is ‘clean, comfortable and adequately drained and which does not adversely affect the calves’. Young-stock are particularly susceptible to disease and if infected may be highly contaminating themselves. Risks of disease transmission will be minimised by preventing calves less than twelve months old from having contact with faeces and slurry from adult cattle. Any calves that are inadvertently born in areas bedded on RMS must be removed as soon as possible from the area, to a location where suitable alternative bedding is provided. 

13. RMS must only be used on cubicle beds, and not as a deep bed in pens or yards 

RMS must only be used in cubicles, either as a layer on top of mattresses, or as a cubicle bed up to 15 cm in depth. It should not be used in calving areas, due to the susceptibility of new-born calves to Johnes disease or other pathogens. 

14. Excellent pre-milking teat preparation must be conducted which must include a pre-milking teat disinfection 

Pre-milking teat disinfection (‘pre-dipping’) allows a rapid reduction in the number of bacteria that are present on the skin of the teats and is associated with lower total bacterial counts (TBC) in bulk milk. 

15. Milk from herds using RMS must be pasteurised 

All bedding materials are potential sources of contamination for milk. Micro-organisms and their spores can get on to the teat from the bedding and through the milking process end up in the milk bulk tank. As a precautionary measure, all milk and milk products derived from farms using RMS must be pasteurised. Unpasteurised milk or milk products must not be consumed (this includes consumption by farmers, farmer families and farm workers). 

16. RMS must not be produced from the faeces of cattle that have been brought into the herd from elsewhere, for a period of one month after their introduction

17. There should be no shared equipment for the handling and processing of feed and RMS 

Designed to prevent cross contamination of feed or forage. 

18. Should any separation equipment be moved between different epidemiological units, it must be thoroughly cleaned and disinfected before moving and subsequent re-use 

In mainland Europe, movement of contaminated equipment has been linked to transfer of pathogens from one farm to another. 

19. Farms using RMS must notify APHA and Red Tractor

In addition to the requirement to notifyRed Tractor (e-mail: dairy@redtractor.org.uk, or phone 0203 617 3670). Farmers must also notify APHA if they wish to use RMS. Complete the form “Notification of Registration of Farmers Using Recycled Manure Solids as Dairy Cattle Bedding” and submit to APHA either by e-mail (ABP@apha.gsi.gov.uk ) or by post to: ABP team, County Hall, Spetchley Road, Worcester, WR5 2NP. 

Recommended best practices 

In addition to the requirements above which must be followed at all times, the seven recommendations in this section should be followed as current best practice.

1. Users of RMS as dairy cow bedding should actively monitor cow health and welfare, in particular intramammary health, as well as bulk tank milk quality as part of their veterinary herd health plan. It is strongly advised that RMS herds have a robust monitoring strategy for MAP. The herd health plan should be regularly reviewed with your vet and the use of RMS should be modified or discontinued if there are signs that it is risking cattle health and welfare, milk quality, or both.

2. Farm personnel should be made aware of the importance of personal hygiene during and following the handling of RMS.

3. RMS should be prepared and stored under cover to avoid an increase in water content prior to application.

4. There should be excellent bedding/cubicle management, including

- Adding RMS to the beds in limited quantities to allow further drying to take place 

- Managing beds to minimise ‘heating’ and therefore microbial multiplication after application

- Designing and managing beds to minimise contamination with urine and fresh faecal material

- Frequent removal (at least daily) of freshly soiled material from bedding)

5. Ventilation and moisture management should be adequate and overstocking avoided, to ensure further drying of RMS once applied to bedding and to minimise the levels of ammonia in the housed atmosphere

6. Water and/or solutions used in footbath wash should not be disposed of in the slurry/manure to be used as RMS bedding

7. Users should have a contingency plan that can quickly be implemented should the use of RMS need to cease, such as loss of OTF status. 

What has AHDB Dairy been doing?

AHDB Dairy has a responsibility to highlight to dairy farmers, who might be considering investing in this technology, the current interpretation of the EU Regulation and the potential practical implications.

In August 2013, AHDB Dairy awarded a research contract to QMMS Ltd, University of Nottingham Vet School and The Dairy Group to conduct a scoping study, reviewing current knowledge worldwide on the use of RMS as bedding for cattle. A specific aim was to collate available evidence on whether any risks arising from the use of RMS for dairy cattle can be sufficiently mitigated to enable it to be authorised for safe use under the EU animal by-products regulation.  

At the same time, AHDB Dairy convened an industry Stakeholders Group which included farming unions (in England, Scotland and Wales), British Cattle Veterinary Association, DairyUK (representing milk buyers), Red Tractor Assurance, equipment suppliers providing RMS technology, commercial consultancies and individual farmers. The purpose was to consider relevant issues from a whole supply chain perspective and, where appropriate, to facilitate greater access to farm data and practical experiences in relation to recommended best practice. A summary of the scoping study is available to download here.

This was followed by further research in winter 2014/15 which involved a survey of over 120 farms bedding on RMS, sand and sawdust, together with replicated experiments at Newton Rigg College. This study was funded by the Welsh Government and provided a greater technical understanding to help inform the legal position with regard to safe use of RMS as bedding. The specific aim was to provide greater technical understanding on the safe use of RMS as bedding, and to investigate management options to safely mitigate any potential risks to animal or human health. The results were intended to inform the regulatory position as well as update current guidance to farmers. A summary report of these results are available to download here.

Where can I get further guidance?  

Further Reading

Green, M.J., Leach, K.A., Breen, J.E., Ohnstad, I., Tuer, S., Archer, S.C., Bradley, A.J. 2014. Recycled manure solids as bedding for dairy cattle: A scoping study. Cattle Practice, Volume 22, Part 2, p207-214

The AHDB Dairy publication 'Housing – a best practice guide' is available to download

Where now in using RMS as bedding for dairy cattle