Bacterial contamination of soil and manure on a cattle farm, depending on the period and place of sample collection

Abstract

The aim of bacteriological examinations was to evaluate soil and manure taken from dairy farms at different times and sampling sites. The study was conducted from September to October. Soil samples were collected directly at the wall of the barn (GI) and at distances of 15 m (GII) and 45 m (GIII) from the livestock facilities. Manure was collected inside the building, at the entrance (KI) and at 1/4 (KII) and ½ (KIII) of its length. Air temperature, relative humidity and the moisture content of the samples were recorded at the sampling sites. The soil and manure samples were subjected to quantitative and qualitative bacteriological examinations conducted in accordance with Polish Standards. Statistical analysis of the results was performed by a one-way analysis of variance and Duncan’s multiple comparison test. The highest number of bacteria in the soil was found at the wall of the barn. Most mesophilic bacteria, actinomycetes, coliforms and E. coli were found in late April and early May, most psychrophilic microorganisms in June, and most proteolytic bacteria at the end of December and in early January. The microbiological contamination of the soil was low (coli titer ≤0.01), amounting to 0.001, and it was detected only at the wall of the barn. The qualitative study of soil revealed only E. coli bacteria. The highest number of microbes in manure was found in samples from the middle of the barn (KIII) taken at the end of April and at the beginning May. Out of the bacteria examined in this study, E. coli and Enterobacter spp. were found in manure samples throughout the study period. While analyzing the impact of selected parameters, such as microclimate and humidity, on manure samples tested for bacteria, a correlation was observed between the presence of all microbes and sample moisture. The bacterial contamination of soil and manure was the biggest during the spring period, which was probably due to climatic and microclimatic conditions. However, the contamination was negligible owing to the absence of pathogenic bacteria and a high soil index. This proved that proper zoohygienic conditions were maintained on the farm.