Article Details: Received: 2020-10-14 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.109-113 The aim of the study was to compare improved bedding composition with conventional straw bedding under farm conditions, regarding its effects on the indicator microorganisms influencing hygiene levels. Dairy cows were housed in newly-built stables divided into two parts each with four sections and bedded cubicles arranged in three rows. In the first part, the bedded cubicle floors were layered with straw up to a height of 20 cm. In the second part, the cubicles were layered to a height of 20 cm with improved bedding composition consisting of recycled manure solids (RMS; 10 kg), ground limestone (200 kg), straw (40 kg) and water (110 l). After layering the bedding was treated with a concrete selector to provide strength and sufficient resistance. Samples for microbiological examination were taken from four sections according to the time interval of production and bedding. From three sections were taken bedding samples according to a new recipe in intervals of 1-3 months after its use. A control sample of bedding, consisting of straw, was taken from the last, fourth section. Comparing classical straw bedding with the improved recipe bedding, the total viable count (TVC) and coliforms bacteria (CB) in a first and second month after laying were found to be reduced. In addition to TVC and CB, decreased numbers of faecal coliforms (FC) and faecal streptococci (FS) were observed in the first, second and third months after layering. In addition to reducing the number of microorganisms, the improved bedding showed a stabilizing effect by keeping the litter thickness up to the bedding threshold (200 mm), which has a beneficial effect for increased purity of the body and udder. Keywords: dairy cows, housing, hygiene, improved bedding, microorganisms References Bradley, A. et al. (2018). The impact of dairy cows’ bedding material and its microbial content on the quality and safety of milk–A cross sectional study of UK farms. International Journal of Food Microbiology, 23(269), 36–45. https://doi.org/10.1016/j.ijfoodmicro.2017.12.022 Broucek, J. et al. (2015). Impact of gestation and lactation stage on the dairy cow response following removal to unfamiliar housing and milking system. Italian Journal of Animal Scince, 14(2), 233–237. https://doi.org/10.4081/ijas.2015.3410 Fournel, S. et al. (2018). Production of recycled manure solids for bedding in Canadian dairy farms: I. Solid-liquid separation . Journal of Dairy Science , 102(2), 1832–1846. https://doi.org/10.3168/jds.2018-14966 Heinonen-Tanski, H. et al. (2006). Methods to reduce pathogen microorganisms in manure. Livestock Science , 102(3), 248–255. https://doi.org/10.1016/j.livsci.2006.03.024 Ismail, R. et al. (2013). Methods for recovering microorganisms from solid surfaces used in the food industry: a review of the literature. International Journal of Environmental Research and Public Health, 10(11), 6169–6183. https://dx.doi.org/10.3390%2Fijerph10116169 Maiorano, G. (2014). Livestock Production for a Sustainable Development. J. Microbiol. Biotechnol. Food Sci. 3 , 34–38. Available online: https://www.jmbfs.org/wp-content/uploads/2014/01/10_jmbfs_maiorano_2014_fs.pdf Leach, K. A. et al. (2015). Recycling manure as cow bedding: Potential benefits and risks for UK dairy farms. Vet. J., 206, 123-130. https://doi.org/10.1016/j.tvjl.2015.08.013 Popescu, S. et al. (2014). The effect of the housing system on the welfare quality of dairy cows . Italian Journal of Animal Scince, 13(1), 2940. https://doi.org/10.4081/ijas.2014.2940 Tancin, V. et al. 2013. Livestock farming in marginal areas (In Slovak), CVŽV, Nitra, Slovakia 2013. p. 70. ISBN 978-80-89418-26-8. Wolfe, T. et al. (2018). Effects of alternative deep bedding options on dairy cow preference, lying behavior, cleanliness, and teat end contamination. Journal of Dairy Science,101(1), 530-536. https://doi.org/10.3168/jds.2016-12358