Recycling manure as cow bedding: potential benefits and risks for UK dairy farms

Material obtained from physical separation of slurry (recycled manure solids; RMS) has been used as bedding for dairy cows in dry climates in the US since the 1970s. Relatively recently, the technical ability to produce drier material has led to adoption of the practice in Europe under different climatic conditions. This review collates the evidence available on benefits and risks of using RMS bedding on dairy farms, with a European context in mind. There was less evidence than expected for anecdotal claims of improved cow comfort. Among animal health risks, only udder health has received appreciable attention. There are some circumstantial reports of difficulties of maintaining udder health on RMS, but no large scale or long term studies of effects on clinical and subclinical mastitis have been published. Existing reports do not give consistent evidence of inevitable problems, nor is there any information on clinical implications for other diseases. The scientific basis for guidelines on management of RMS bedding is limited. Decisions on optimum treatment and management may present conflicts between control of different groups of organisms. There is no information on the influence that such 'recycling' of manure may have on pathogen virulence. The possibility of influence on genetic material conveying antimicrobial resistance is a concern, but little understood. Should UK or other non-US farmers adopt RMS, they are advised to do so with caution, apply the required strategies for risk mitigation, maintain strict hygiene of bed management and milking practices and closely monitor the effects on herd health

Using Manure Solids as Bedding - Final Report

Six farms using different types of dried manure solid (DMS) strategies, including a farm that had side-by- side pens using sand and DMS, participated in a study to assess the impact on herd health of using DMS as bedding on dairy farms in the Northeast. Samples of unused and used bedding were taken over the course of a year and analyzed for bacterial content and physical properties. Mastitis and somatic cell count (SCC) records were analyzed in relation to those properties. Sand bedding started out “cleaner” than DMS bedding, but once in the stalls, the bacterial load of several organisms was highest in sand. In addition, DMS with the least bacterial numbers in the unused tended to have the highest bacterial numbers in the used bedding. A comparison of bacterial concentrations in unused and used air-dried DMS versus composted DMS did not show composted to be consistently lower and calls into question the value of composting DMS prior to bedding. Bacteria in the unused bedding had little to no effect on bacteria in the used indicating that bacterial levels in used bedding are more dependent on bacterial levels in the manure of the cows using the stalls and how well the stalls are scraped, rather than the cleanliness of the bedding before it is place in the stalls. Levels of Streptococcus, Klebsiella and gram negative and positive bacteria were significantly higher on the teat ends of cows bedded on DMS versus those bedded on sand, but SCC and mastitis for those cows did not differ between bedding materials. Although mastitis differed among farm/bedding strategies, bacteria levels and properties of bedding had no effect on mastitis incidence. Lactation number, stage of lactation and SCC were the significant variables. Decreased levels of Klebsiella in the used bedding increased the odds of having an abnormal SCC for one FBS, and decreased moisture and fine particles in the used bedding increased the odds of having an abnormal SCC for a different FBS. For all others, abnormal cell counts were affected only by season, lactation number and milk production. Concern that continued use of DMS will increase SCC was not borne out using linear regression of 10 years worth of linear score data. Although 2 of 6 farms showed an increase in linear score while using DMS, it was not different from the change in linear score prior to using DMS. Lameness was higher in cows bedded on sand compared to DMS. Economic analysis a savings of between 1 and 26 cents per hundred weight of milk produced through the use of manure solids as bedding on five farms. This study suggests that properly managed DMS can provide an economic benefit without compromising herd health.The New York State Energy Research and Development Authorit

Reduction of Selected Pathogens in Anaerobic Digestion

Anaerobic digesters are becoming a popular waste treatment option in New York State. These systems generate energy for on-farm use and sale while providing significant odor reduction. Research has shown that mesophilic systems (T=100oF) have the potential to reduce pathogens entering the environment. A plug flow digester was monitored for 14 months starting in May 2001. Samples taken from the digester influent and effluent were tested for the fecal coliform group of indicator organisms and Mycobacterium avium subspecies paratuberculosis (Map). M. avium paratuberculosis is the microorganism responsible for Johne’s disease in dairy cattle and other ruminants. Results show almost a 3-log reduction in fecal coliforms and slightly more than a 2-log reduction in Map. This paper describes an anaerobic digester and shows the comparative results of testing between a farm with a digester and a farm without a digester. Since both farms in this study compost and sell excess solids, analyses were done on the composted manure as well

Reduction of Selected Pathogens in Anaerobic Digestion

Anaerobic digesters are becoming a popular waste treatment option in New York State. These systems generate energy for on-farm use and sale while providing significant odor reduction. Research has shown that mesophilic systems (T=100oF) have the potential to reduce pathogens entering the environment. A plug flow digester was monitored for 14 months starting in May 2001. Samples taken from the digester influent and effluent were tested for the fecal coliform group of indicator organisms and Mycobacterium avium subspecies paratuberculosis (Map). M. avium paratuberculosis is the microorganism responsible for Johne’s disease in dairy cattle and other ruminants. Results show almost a 3-log reduction in fecal coliforms and slightly more than a 2-log reduction in Map. This paper describes an anaerobic digester and shows the comparative results of testing between a farm with a digester and a farm without a digester. Since both farms in this study compost and sell excess solids, analyses were done on the composted manure as well