Cilj rada bio je ispitati utjecaj fermentacije kozjeg i kravljeg mlijeka ABT- 2 kulturom na promjenu udjela pojedinačnih masnih kiselina u kozjem i kravljem mlijeku. Svrha rada bila je utvrditi povećanje udjela pojedinačnih kratko (SCFA - short chain fatty acids) i srednje (MCFA - middle chain fatty acids) lančanih masnih kiselina tijekom fermentacije kozjeg i kravljeg mlijeka. Hipoteza u radu bila je da veći udjeli SCFA i MCFA tijekom fermentacije ABT-2 kulturom nastaju u kozjem nego u kravljem mlijeku. Rezultati rada pokazali su da se fermentacijski procesi brže odvijaju u kozjem mlijeku u usporedbi s kravljim. Statistički značajno veći broj stanica probiotičkih bakterija Bifidobacterium spp. i Lactobacillus acidophilus La zabilježen je tijekom fermentacije kozjeg mlijeka, uz istodobno brže padanje pH vrijednosti kozjeg mlijeka u odnosu na kravlje. Uslijed fermentativne aktivnosti bifidobakterija iz ABT-2 kulture povećavao se udio SCFA i MCFA u obje vrste mlijeka. Međutim, značajno veći udio mjerenih SCFA i MCFA nastao je fermentacijom kozjeg mlijeka.In this paper, changes in composition and contents of each fatty acid during fermentation with ABT-2 culture were examined. The objective of this study was to determinate the increase of short (SCFA) and medium (MCFA) chain fatty acids in goat\u27s and cow\u27s milk during fermentation with ABT-2 culture. The hypothesis of this study was that higher contents of SCFA and MCFA are produced in goat\u27s milk in comparison with cow\u27s milk, during fermentation with ABT-2 culture. Obtained results have shown that fermentation process in goat\u27s milk is faster than in cow\u27s milk. The number of viable cells of probiotic bacteria Lactobacillus acidophilus La-5 and Bifidobacterium spp. was statistically greater in goat\u27s milk than in cow\u27s milk; consequently, pH value decreased more obviously in goat\u27s milk than in cow\u27s milk during whole fermentation process. Increase of SCFA and MCFA contents during fermentation was noted in both types of milk due to activity of bifidobacteria derived from ABT-2 culture. However, considerably higher amounts of examined SCFA and MCFA were produced in goat\u27s milk than in cow\u27s milk