Interventions to reduce the bacterial load in recycled broiler litter

Abstract

Two experiments were undertaken to evaluate the bacterial load in recycled litter between broiler flocks following addition of quicklime (T1), windrowing (T2), shallow fermentation (T3), and control (no intervention, T4). The first experiment was developed in field conditions in which the broiler houses were accompanied by 6 consecutive flocks and the effect of the treatments was assessed on enterobacteria and aerobic mesophiles. The second experiment was conducted in an experimental broiler house with recycled litter for assessment of Salmonella Enteritidis phage type 4 (SE PT4). In the field study, T3 presented the best results in reducing enterobacteria in broiler litter in relation to the other treatments, with the highest reduction occurring in the first 3 flocks, tending to stabilization from the fourth flock onward for all the treatments assessed. From the third to sixth flocks, enterobacteria level at the end of the treatments (d 12) was lower than the average in the fresh litter, except in T4. All treatments reduced aerobic mesophiles throughout the flocks, where T2 showed the highest reduction. The percentage of dry matter in the broiler litter diminished in T4 and increased in T3 over the course of the flocks. In the second experiment, the drop in the SE PT4 level in the broiler litter first occurred in T2 and T3. However, all the treatments except for T4 eliminated SE PT4 within 12 d. The temperature of the broiler litter in T2 was higher in relation to the other treatments. The results show that litter treatment prior to reutilization by the successive broiler flock is required to reduce the level of residual bacteria. The fermentative treatments (T2 and T3) were found to be superior to the others in terms of reducing the bacterial load, with shallow fermentation standing out with the highest reduction of enterobacteria and equivalent SE PT4 elimination when compared to windrowing.

Antibiotic resistance and virulence factors among Escherichia coli isolates from avian organic fertilizer

“…The feasibility of chicken production depends on the economic and environmental sustainability of the management system of the poultry litter discard. In Brazil, reuse of poultry litter is considered when the previous flocks did not present clinical or subclinical infection during housing (VAZ et al, 2017) and the litter can be reused for six cycles of chicken growing (VAZ et al, 2017).…”

“…However, the organic waste may not always be suitable for a correct composting, it means that sometimes it is necessary to increase the carbon disposable by adding an additional biodegradable organic matter and active biomass to the occurrence of the thermophilic phase (SONG et al, 2014). In the windrowing technique only the poultry litter was piled and covered with a black tarpaulin promoting an incomplete composting process, actually a fermentative process with low temperatures (<50 o C) depending on the bedding material used in the poultry houses (VAZ et al, 2017). In the present research the temperature reaches a maximum of 38 o C what was not enough for a good thermophilic phase.…”

“…According to VAZ et al, (2017) after the removal of the poultry floc, the caked portions of the bedding material are eliminated and the remaining litter was windrowed at the center of the poultry house, forming a single pile, which was covered with a 200 µm non-breathable black tarpaulin for 10 days. Then the tarpaulin was removed, and the litter was redistributed throughout the poultry house for a new poultry flock housing.…”

“…Due to economic reasons litter is often reutilized for several flocks, sometimes for 6 consecutives flocks (SONODA et al, 2012). During downtime between flocks the poultry litter is subjected to an in-house treatment aiming to reduce or inactivating residual microorganisms (VAZ et al, 2017). Studies have been indicated that manure-borne pathogens can survive in secondary habitats (i.e., manures, soils, and water) for weeks or even months, with their survival depending on the organism and soil biological, chemical, and physical conditions (ISHII et al, 2010).…”

Contribution of organic amendments to soil properties and survival of Stenocarpella on maize stalk

“…Although nutrients could be limiting factors in stalks (Torma et al, 2017), when supplied at higher amounts, such as those amended in poultry litter, nutrients may lead to Stenocarpella inoculum buildup. Lime and/or superphosphate for disinfection are incorporated where poultry litter is reused for a new batch of hens (Soliman et al, 2018;Vaz et al, 2017). Superphosphate increases the P content of manure, which raises its fertilizing strength.…”