Using Ultraviolet Irradiation to Disinfectcompound Feeds

Abstract

Compound feeds are sources of not only nutrients required to maintain animals’ vital activity, but also of a complex of microorganisms inhabiting them. This complex develops in them after the heat treatment of raw materials (extrusion, conditioning, expansion, etc.), which creates non-competitive conditions for the foreign microorganisms to enter (in particular, from non-grain and animal raw materials). At the same time, the animal's gastrointestinal tract contains its own complex microbiome, which in young animals (at the time of switching to pre-starter) is not yet fully formed and not very stable. It can be disturbed by foreign microbiota, which will lead to a decrease in productivity. In addition, the foreign microbiota requires an immune response from the body, which is a very energy-consuming process. Therefore, the disinfection of compound feed for young animals at the stage of production and in finished form is reasonable and important. The most promising method of disinfection today is ultraviolet irradiation, which is widely used for disinfection of surfaces, air and water. It is cheap, easy in mounting and maintenance and effective without disrupting any properties of the product or feed. For compound feeds, it is currently used only on livestock farms, and is not used on production lines. Therefore, the task of this study was to test the effectiveness of ultraviolet irradiation of a compound feed for further implementation in manufacture. Irradiation with a bactericidal lamp of a model feed mixture (60% crushed wheat, 30% sunflower oilcake, 10% wheat bran) was conducted. The numbers of MAFAnM (mesophilic aerobic and facultatively anaerobic microorganisms) declined from 1 million to 20 thousand cells per gram after 5 hours (300 minutes) of UVC exposition (254 nm wavelength). The diagram obtained coincides well with the reference diagram for a typical bacterial strain and shows that the use of ultraviolet irradiation is quite effective even without requiring a long-time exposition. Therefore, it can be used industrially to disinfect compound feeds and their raw materials.