Microbiological safety of the accelerated manure processing technology

Modern animal husbandry requires new environmentally friendly technologies for the processing and disposal of its by-products (BPAH), namely: manure and manure effluents from livestock complexes. One of these technologies is the production of reconstituted litter (RL) in Bedding Recovery Units (BRU) from cattle manure, introduced at one of the dairy complexes in the Kirov region. The recycling technology used made it possible to obtain a homogeneous product of a soft, loose consistency, high hydroscopicity, brown color with a weak characteristic earthy odor. Manure processing in BRU for 24 h at a temperature within 69±4°C contributes to a significant decrease in the humidity of manure effluents, an increase in the mass fraction of organic matter, ash content, pH, as well as a significant decrease of the total number of microorganisms (MO) (by 68.2 times) and species diversity (by 2.2 times). Proteus, Fusobacterium, Prevotella, Pseudomonas, Peptococcus, Aspergillus , and Klebsiella , which are among the causative agents of mastitis, have disappeared from the microbiota. The numbers of opportunistic Enterococci decreased from (8.0±0.5)×10 6 down to (5.0±0.5)×10 4 CFU/ml. After processing in BRU, Bifidobacteria took a dominant position in the composition of microbiota in RL (63% of the total number of identified MO). This fact should be regarded as an advantage of the used technology and one of the advantages of the RL. However, conditionally pathogenic microorganisms of the genera Clostridium, Bacteroides, Peptostreptococcus, Veillonella , and Candida showed high resistance to manure effluent processing in BRU. According to the chemical analysis results, the content of cattle on RL led to the accumulation of nitrogen, phosphorus and potassium in litter manure, which is due to the gradual degradation of organic components of RL during recycling. The presented results can be used to optimize the parameters of processing cattle manure using BRU to improve the quality of RL.