Investigation of the microclimate of poultry houses and chemical composition of poultry litter, depending on the time of its accumulation in the cage batteries

Abstract

One of the main reasons of the destabilization of the ecological environment around poultry farms is the widespread use of resource-consuming and environmentally irrational production processes and technological preparation, processing and disposal of poultry waste. Nowadays, cage batteries with a belt removal system are becoming more widespread in the poultry farming. However, the use of such equipment does not guarantee compliance with applicable veterinary and sanitary requirements for the content of harmful gases in the air of the poultry houses and its microbial contamination. This, in turn, has a negative impact on the state of the environment. In addition, the equipment designed for countries with a milder climate than in Ukraine does not support the designed regimes of its individual systems. Therefore, the study of the effect of the accumulation of the litter on the belts of the cage batteries on its humidity, chemical composition and microclimate in the poultry house, from the environmental point of view, remains an urgent problem. On the basis of complex studies, the kinetics of the drying of the litter on the belt conveyors of the cage batteries for keeping laying hens with built-in air ducts and without air ducts in different seasons, as well as the effect of the duration of the accumulation of the litter on the microclimate in the poultry house, microbial contamination and chemical composition of the litter have been studied. The study of the microclimate in the poultry house, depending on the time of accumulation of the litter on the conveyor belts, showed that with the increase in the time of accumulation of excrements in the air, the content of ammonia increased, and after 5 days of accumulation in the cold season its level began to exceed the maximum contamination level (MCL)-15 mg per m3 of the air. The amount of ammonia on the 7th day of the litter accumulation in all poultry houses was 1.8-2.8 times greater (P<0.001) compared to the first day. The amount of carbon dioxide in the air increased by 1.14-2.00 times, but it never exceeded the MCL - 0.25%. When studying the both types of cage batteries, 1.2-2.6 times the maximum contamination level of the air (220 thous. microbic units per m3) was established in the poultry houses. In the case of cage batteries without built-in ducts from the 1st to the 7th day of accumulation, microbial air contamination increased by 1.9 times in the cold season, and by 1.7 times - in the warm season; and on the 7th day it was 579 and 462 thous. microbic units per m3, respectively. When using the cage batteries with built-in ducts, microbial air contamination increased slightly: by 1.7 times in the cold season and 1.4 times in the warm season and on the 7th day it was 535 and 580 thous. units per m3, respectively.