The economics of the treatment of dairy cow slurry by anaerobic digestion

1986 ◽  
Vol 35 (4) ◽  
pp. 259-276 ◽  
Author(s):  
D.J. Parsons
AGROFOR ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Maarit HELLSTEDT ◽  
Hannu E.S. HAAPALA

Agriculture is the most significant source of Ammonia emission that causes e.g. loss of Nitrogen from agricultural systems. Manure is the main source of Ammonia emissions and causes losses in the nutrient cycles of agriculture as well as local odour nuisance. By using different bedding materials, it is possible to reduce both the Ammonia emissions and to improve the cycling of nutrient. Peat is known as an effective litter material but its use as a virtually non-renewable resource is questionable. Therefore, we need to find new bedding materials to replace peat. In this study, the effect of ten different industrial by-products, reeds and stalks to reduce Ammonia emissions was tested in laboratory in January 2020. Dairy cow slurry and bedding materials were mixed in a volume ratio of 4:1. The Ammonia emission was measured for two weeks once or twice a day. Measurements were performed with a photoacoustic method. The results show that all tested materials reduce the Ammonia emission from the cow slurry used. Interesting new materials to substitute peat are zero fiber and briquetted textile waste. Wheat bran, pellets made of reed canary grass and chopped bulrush had the best effect which is at the same level as that of peat. However, no statistically significant differences between the calculated emission rates were found.


2015 ◽  
Vol 3 (6) ◽  
Author(s):  
R. Smith ◽  
M. O’Hara ◽  
J. L. Hobman ◽  
A. D. Millard

The diversity of bacteriophages in slurry from dairy cows remains largely unknown. Here, we report the draft genome sequences of 14 bacteriophages isolated from dairy cow slurry using Escherichia coli K-12 MG1655 as a host.


2021 ◽  
Vol 12 ◽  
Author(s):  
Satoshi Katada ◽  
Akira Fukuda ◽  
Chie Nakajima ◽  
Yasuhiko Suzuki ◽  
Takashi Azuma ◽  
...  

Efficient methods for decreasing the spread of antimicrobial resistance genes (ARGs) and transfer of antimicrobial-resistant bacteria (ARB) from livestock manure to humans are urgently needed. Aerobic composting (AC) or anaerobic digestion (AD) are widely used for manure treatment in Japanese dairy farms. To clarify the effects of AC and AD on antimicrobial resistance, the abundances of antimicrobial (tetracycline and cefazolin)-resistant lactose-degrading Enterobacteriaceae as indicator bacteria, copy numbers of ARGs (tetracycline resistance genes and β-lactamase coding genes), and concentrations of residual antimicrobials in dairy cow manure were determined before and after treatment. The concentration of tetracycline/cefazolin-resistant lactose-degrading Enterobacteriaceae was decreased over 1,000-fold by both AC and AD. ARGs such as tetA, tetB, and blaTEM were frequently detected and their copy numbers were significantly reduced by ∼1,000-fold by AD but not by AC. However, several ARG copies remained even after AD treatment. Although concentrations of the majority of residual antimicrobials were decreased by both AC and AD, oxytetracycline level was not decreased after treatment in most cases. In addition, 16S rRNA gene amplicon-based metagenomic analysis revealed that both treatments changed the bacterial community structure. These results suggest that both AC and AD could suppress the transmission of ARB, and AD could reduce ARG copy numbers in dairy cow manure.


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