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Abstract There are different types of effluents from farming operations including untreated slurry (a mixture of manure, urine, split feed, and water), and treated slurry that normally is filtered to separate the solid fraction from the liquid fraction. With the amount of slurry applied on the soils as fertiliser every year, there are necessary to measure the leaching of microbial capable of transmitting infective agents that can be normally on slurry, because slurry can be a potential biohazard capable of transmitting infective agents. The aim of this study was to investigate the presence and survival of Escherichia coli (E. coli) on liquid fraction of dairy slurry, with the addition of different treatments during storage, such as addition of Biochar, beneficial microorganisms, sulphuric acid and the combinations of them. All the applied treatments to slurry show statistically significant differences (P < 0.001), according to the different sampling dates. Results showed that there are conditions and treatments that benefit the survival probability of E. coli , the treatments that include the acidification of slurry have the highest averages of CFU/ml (243288.3 at 37 °C; 136584 at 44 °C). These results can contribute to the improvement of the quality of slurry applied on soils, beneficiating agriculture but also public health. Highlights • Investigate the survival of E. coli on liquid fraction of dairy slurry. • Results showed treatments used benefit the survival probability of E. coli. • Treatments with acidification of slurry have the highest averages CFU E. coli /ml. • Addition of Biochar and beneficial microorganisms reduce CFU E. coli /ml. [ABSTRACT FROM AUTHOR]

Decomposition of dairy cows' excreta on housing floor leads to ammonia and greenhouse gases production, yet factors affecting total emissions have not been fully disclosed. This work aimed to assess the impact of lactation stage, feeding system and sampling time on gaseous emission potential of cow's faeces and urine in laboratory chambers systems. Individual faeces and urine were collected from two groups of four cows, at peak and post peak lactation, from three commercial farms with distinct feeding systems: total mixed ration (TMR), total mixed ration plus concentrate at robot (TMR + robot), and total mixed ration plus concentrate in automatic feeders (TMR + AF). Samples were collected before a.m. (T8h), at middle day (T12h), and before p.m. (T17h) milking. In a laboratory chambers system, faeces and urine were mixed in a ratio of 1.7:1, and ammonia and greenhouse gases emissions were monitored during 48-h. Cumulative N–N 2 O emissions were the highest in TMR + robot system, post peak cows and sampling time T17h. An interaction between stage of lactation and sampling time was detected for N–NH 3 and N–N 2 O (g/kg organic soluble N) emissions. Post peak cows also produced the highest cumulative N–NH 3 emissions. Overall results contribute for the identification of specific on-farm strategies to reduce gaseous emissions from cows' excreta. • Feeding systems, stage of lactation and sampling time altered GHG and NH 3 emissions. • Emissions of N–N 2 O were highest at TMR + robot and of N–NH 3 at TMR and TMR + AF systems. • Higher cumulative N–N 2 O and N–NH 3 emissions were observed in post peak lactation. • Excreta collected at T17h led to the highest N–N 2 O cumulative emissions. [ABSTRACT FROM AUTHOR]