Effect of Organic Acids and Bacterial-enzymatic Preparations on the Number of Fungal Populations and Silage Aerobic Stability

The impact of conservation additives, based on formic and propionic acids and bacterial-enzymatic preparations, on the number of mould fungi and yeast cells in silages was investigated. Silages were prepared from red clover (Trifolium pratense L.), Italian ryegrass (Lolium multiflorum L.) and their mixtures prepared at the ratio of 50:50. The aim of the experiment was to examine the influence of the applied additives on the oxygen stability of silages. The chemical analyses of silages included: the content of dry matter, lactic and butyric acids, ethanol and pH value. The applied preparations reduced the number of mould fungi and yeast cells in all the examined silages. The strongest inhibitory effect on the development of fungi was exerted by the preparation containing organic acids (KemiSile 2000). In the case of the silage from red clover, the number of mould fungi dropped (P<0.05) from 16.3 10 CFU g FM in the control to 7.5 10 CFU g FM in the treatment with the addition of KemiSile 2000. The number of yeast cells declined (P<0.05) from 447.3 10 CFU g FM in the control to 247.5 10 CFU g 1 FM after the treatment with KemiSile 2000. In Italian ryegrass silage KemiSile 2000 reduced (P<0.05) the number of mould fungi from 7.5 10 CFU g FM in the control to 3.5 10 CFU g FM. The number of yeasts cells declined (P<0.05) from 343.5 10 CFU g FM in the control to 175.3 10 CFU g 1 FM. In silage prepared from mixtures of Italian ryegrass and red clower (50:50) after treating with KemiSile 2000 the number of mould fungi was reduced (P<0.05) from 11.7 10 CFU g FM in the control to 5.7 10 CFU g FM, the number of yeasts cells declined (P<0.05) from 438.0 10 CFU g FM in the control to 213.1 10 CFU g FM. The examined bacterial-enzymatic preparations (Lactacel L and VTT) were found to be less effective. Nevertheless, all the tested preparations improved aerobic stability of silages.